Main halyard pulley?? is stuck at top of mast.

Boat has been sitting in a slip for several years -- never sailed during that time. Tried yesterday to raise the main sail -- no luck. Pulling down as hard as possible in the halyard line will not budge it. My minimal understanding of the seat used to hoist someone up to the top of the mast tells me it must use the halyard line. If so, is there any other method to get someone to the top of the mast?? Would like to avoid stepping the mast but that may be the only option. All ideas welcome.

Drop the halyard for the foresail, if you have roller furling you will have to lower the foresail. greg From: "ma… [at] pacbell.net" <ma… [at] pacbell.net> To: Ca… [at] yahoogroups.com Sent: Sun, August 29, 2010 5:31:16 PM Subject: [Cal_Boats] Main halyard pulley?? is stuck at top of mast. Boat has been sitting in a slip for several years -- never sailed during that time. Tried yesterday to raise the main sail -- no luck. Pulling down as hard as possible in the halyard line will not budge it. My minimal understanding of the seat used to hoist someone up to the top of the mast tells me it must use the halyard line. If so, is there any other method to get someone to the top of the mast?? Would like to avoid stepping the mast but that may be the only option. All ideas welcome.

What kind of boat do you have? I had a cal 25 and the main halyard was flagging in a breeze and went over the top of the mast and then foulded the jib halyard. I was able to lift the main halyard by tying a stick to the spinnaker halyard and using this to lift the fouled halyard. A large gun is required to get me to consider going to the top of a 12' ladder, the top of my mast is only seen by me when it is on the ground. _____ From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of ma… [at] pacbell.net Sent: Sunday, August 29, 2010 4:31 PM To: Ca… [at] yahoogroups.com Subject: [Cal_Boats] Main halyard pulley?? is stuck at top of mast. Boat has been sitting in a slip for several years -- never sailed during that time. Tried yesterday to raise the main sail -- no luck. Pulling down as hard as possible in the halyard line will not budge it. My minimal understanding of the seat used to hoist someone up to the top of the mast tells me it must use the halyard line. If so, is there any other method to get someone to the top of the mast?? Would like to avoid stepping the mast but that may be the only option. All ideas welcome.

I don't know about the safety aspect compared to the main halyard, but when my main was fouled I went up the mast with the spinnaker halyard since we have roller furling on the jib. It worked, but who knows how safe it was. Richard Anderson 1975 Cal 2-29 --- In Ca… [at] yahoogroups.com, "John Boyce" <jecyob@...> wrote: > > What kind of boat do you have? I had a cal 25 and the main halyard was > flagging in a breeze and went over the top of the mast and then foulded the > jib halyard. I was able to lift the main halyard by tying a stick to the > spinnaker halyard and using this to lift the fouled halyard. A large gun is > required to get me to consider going to the top of a 12' ladder, the top of > my mast is only seen by me when it is on the ground. > > _____ > > From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf > Of macsolns@... > Sent: Sunday, August 29, 2010 4:31 PM > To: Ca… [at] yahoogroups.com > Subject: [Cal_Boats] Main halyard pulley?? is stuck at top of mast. > > > > > Boat has been sitting in a slip for several years -- never sailed during > that time. > > Tried yesterday to raise the main sail -- no luck. Pulling down as hard as > possible in the halyard line will not budge it. > > My minimal understanding of the seat used to hoist someone up to the top of > the mast tells me it must use the halyard line. If so, is there any other > method to get someone to the top of the mast?? > > Would like to avoid stepping the mast but that may be the only option. > > All ideas welcome. >

I did the same thing, with a prussic knot on the jib halyard. Walter S/V Ita CAL 29 --- On Mon, 8/30/10, wirelessmonster <ri… [at] richardanderson.net> wrote: From: wirelessmonster <ri… [at] richardanderson.net> Subject: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. To: Ca… [at] yahoogroups.com Date: Monday, August 30, 2010, 4:53 AM I don't know about the safety aspect compared to the main halyard, but when my main was fouled I went up the mast with the spinnaker halyard since we have roller furling on the jib. It worked, but who knows how safe it was. Richard Anderson 1975 Cal 2-29 --- In Ca… [at] yahoogroups.com, "John Boyce" <jecyob@...> wrote: > > What kind of boat do you have? I had a cal 25 and the main halyard was > flagging in a breeze and went over the top of the mast and then foulded the > jib halyard. I was able to lift the main halyard by tying a stick to the > spinnaker halyard and using this to lift the fouled halyard. A large gun is > required to get me to consider going to the top of a 12' ladder, the top of > my mast is only seen by me when it is on the ground. > > _____ > > From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf > Of macsolns@... > Sent: Sunday, August 29, 2010 4:31 PM > To: Ca… [at] yahoogroups.com > Subject: [Cal_Boats] Main halyard pulley?? is stuck at top of mast. > > > > > Boat has been sitting in a slip for several years -- never sailed during > that time. > > Tried yesterday to raise the main sail -- no luck. Pulling down as hard as > possible in the halyard line will not budge it. > > My minimal understanding of the seat used to hoist someone up to the top of > the mast tells me it must use the halyard line. If so, is there any other > method to get someone to the top of the mast?? > > Would like to avoid stepping the mast but that may be the only option. > > All ideas welcome. >

Hello, macsolns. Based on the statement below, I would involve someone in this endeavor who knows something about how the halyards, blocks, lines, and sheaves are set up (and not the kid from the rigger's who considers himself indestructible). Running someone up the mast is dangerous, and involves a number of safety precautions. Also helps if said runner-up-the-mast has some idea of what they will be looking for. there are a number of possible failure and fouling modes. "My minimal understanding of the seat used to hoist someone up to the top of the mast tells me it must use the halyard line." Your line grinders (person/people) are important in terms of knowing how to maintain line tensions, and handle tension on back-up lines. Coming down smoothly can be important. Your climber should know how to assist in the process so they are not just dead weight going up the mast. Also need to know your boat model, and what it is rigged for (spin?, boom lift?, dual jib halyard?, int/ext hals?). Maybe there is another boat in the yard that has a mast down where you can study the basics of the line set-ups? Perfectly doable. Just suggesting that some experience and caution helps. Cheers Charlie CAL 25s - CAL 40 Annapolis From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of John Boyce Sent: Sunday, August 29, 2010 9:00 PM To: Ca… [at] yahoogroups.com Subject: RE: [Cal_Boats] Main halyard pulley?? is stuck at top of mast. What kind of boat do you have? I had a cal 25 and the main halyard was flagging in a breeze and went over the top of the mast and then foulded the jib halyard. I was able to lift the main halyard by tying a stick to the spinnaker halyard and using this to lift the fouled halyard. A large gun is required to get me to consider going to the top of a 12' ladder, the top of my mast is only seen by me when it is on the ground. From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of ma… [at] pacbell.net Sent: Sunday, August 29, 2010 4:31 PM To: Ca… [at] yahoogroups.com Subject: [Cal_Boats] Main halyard pulley?? is stuck at top of mast. Boat has been sitting in a slip for several years -- never sailed during that time. Tried yesterday to raise the main sail -- no luck. Pulling down as hard as possible in the halyard line will not budge it. My minimal understanding of the seat used to hoist someone up to the top of the mast tells me it must use the halyard line. If so, is there any other method to get someone to the top of the mast?? Would like to avoid stepping the mast but that may be the only option. All ideas welcome.

drop mast. other halyards are now suspect. Reggie To: Ca… [at] yahoogroups.com From: hu… [at] bah.com Date: Mon, 30 Aug 2010 07:12:20 -0400 Subject: RE: [Cal_Boats] Main halyard pulley?? is stuck at top of mast. Hello, macsolns. Based on the statement below, I would involve someone in this endeavor who knows something about how the halyards, blocks, lines, and sheaves are set up (and not the kid from the rigger's who considers himself indestructible). Running someone up the mast is dangerous, and involves a number of safety precautions. Also helps if said runner-up-the-mast has some idea of what they will be looking for. there are a number of possible failure and fouling modes. "My minimal understanding of the seat used to hoist someone up to the top of the mast tells me it must use the halyard line." Your line grinders (person/people) are important in terms of knowing how to maintain line tensions, and handle tension on back-up lines. Coming down smoothly can be important. Your climber should know how to assist in the process so they are not just dead weight going up the mast. Also need to know your boat model, and what it is rigged for (spin?, boom lift?, dual jib halyard?, int/ext hals?). Maybe there is another boat in the yard that has a mast down where you can study the basics of the line set-ups? Perfectly doable. Just suggesting that some experience and caution helps. Cheers Charlie CAL 25s - CAL 40 Annapolis From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of John Boyce Sent: Sunday, August 29, 2010 9:00 PM To: Ca… [at] yahoogroups.com Subject: RE: [Cal_Boats] Main halyard pulley?? is stuck at top of mast. What kind of boat do you have? I had a cal 25 and the main halyard was flagging in a breeze and went over the top of the mast and then foulded the jib halyard. I was able to lift the main halyard by tying a stick to the spinnaker halyard and using this to lift the fouled halyard. A large gun is required to get me to consider going to the top of a 12' ladder, the top of my mast is only seen by me when it is on the ground. From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of ma… [at] pacbell.net Sent: Sunday, August 29, 2010 4:31 PM To: Ca… [at] yahoogroups.com Subject: [Cal_Boats] Main halyard pulley?? is stuck at top of mast. Boat has been sitting in a slip for several years -- never sailed during that time. Tried yesterday to raise the main sail -- no luck. Pulling down as hard as possible in the halyard line will not budge it. My minimal understanding of the seat used to hoist someone up to the top of the mast tells me it must use the halyard line. If so, is there any other method to get someone to the top of the mast?? Would like to avoid stepping the mast but that may be the only option. All ideas welcome.

wirelessmonster wrote: > > > > I don't know about the safety aspect compared to the main halyard, but > when my main was fouled I went up the mast with the spinnaker halyard > since we have roller furling on the jib. It worked, but who knows how > safe it was. > My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. Chris Campbell

Why can't you unroll the jib, lower it then use the jib halyard? You can then use the spin halyard as the safety backup. John From: Chris Campbell <cl… [at] charterinternet.com> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 9:15:46 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. wirelessmonster wrote: > >I don't know about the safety aspect compared to the main halyard, but when my >main was fouled I went up the mast with the spinnaker halyard since we have >roller furling on the jib. It worked, but who knows how safe it was. > My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. Chris Campbell

When we go up the mast we use a halyard to hoist up a 3:1 tackle then run that thru a winch...Its much faster and reduces the load on the halyard and sheave. Mark ----- Original Message ----- From: John Courter To: Ca… [at] yahoogroups.com Sent: Monday, August 30, 2010 9:36 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Why can't you unroll the jib, lower it then use the jib halyard? You can then use the spin halyard as the safety backup. John ------------------------------------------------------------------------------ From: Chris Campbell <cl… [at] charterinternet.com> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 9:15:46 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. wirelessmonster wrote: I don't know about the safety aspect compared to the main halyard, but when my main was fouled I went up the mast with the spinnaker halyard since we have roller furling on the jib. It worked, but who knows how safe it was. My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. Chris Campbell __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

Hi All On Lake Pepin in Wisconsin we'd use the ~80' mast raising pole with super duty winch and 3/8" steel cable to send up the brave soul in the bosuns chair. Just a thought. Jeff Raethke Cal 2-25 "Molly Rose" On Aug 30, 2010, at 1:47 PM, "Mark Alan Stahnke \(MAS Consulting\)" <ma… [at] cox.net> wrote: >  > > When we go up the mast we use a halyard to hoist up a 3:1 tackle then run that thru a winch...Its much faster and reduces the load on the halyard and sheave. > Mark > > ----- Original Message ----- > From: John Courter > To: Ca… [at] yahoogroups.com > Sent: Monday, August 30, 2010 9:36 AM > Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. > > > Why can't you unroll the jib, lower it then use the jib halyard? You can then use the spin halyard as the safety backup. > > John > > From: Chris Campbell <cl… [at] charterinternet.com> > To: Ca… [at] yahoogroups.com > Sent: Mon, August 30, 2010 9:15:46 AM > Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. > > > wirelessmonster wrote: > >> >> >> I don't know about the safety aspect compared to the main halyard, but when my main was fouled I went up the mast with the spinnaker halyard since we have roller furling on the jib. It worked, but who knows how safe it was. >> > > My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). > > You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. > > Chris Campbell > > > > > __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ > > The message was checked by ESET NOD32 Antivirus. > > http://www.eset.com > > > __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ > > The message was checked by ESET NOD32 Antivirus. > > http://www.eset.com >

Jeff Raethke wrote: > > Hi All > On Lake Pepin in Wisconsin we'd use the ~80' mast raising pole with > super duty winch and 3/8" steel cable to send up the brave soul in the > bosuns chair. Sounds safer than the elderly halyards on a long-unused boat. Chris Campbell >

It actually increases load on the halyard. Taking the simplest case, a block hoisted up on the halyard gets you no advantage, but if you're lifting 100 lbs, then there is 100 lbs of load on each part adding to 200 lbs of load on the halyard supporting the block. John From: Mark Alan Stahnke (MAS Consulting) <ma… [at] cox.net> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 11:47:05 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  When we go up the mast we use a halyard to hoist up a 3:1 tackle then run that thru a winch...Its much faster and reduces the load on the halyard and sheave. Mark >From: John Courter >To: Ca… [at] yahoogroups.com >Sent: Monday, August 30, 2010 9:36 AM >Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. > > >Why can't you unroll the jib, lower it then use the jib halyard? You can then >use the spin halyard as the safety backup. > >John > > > > From: Chris Campbell <cl… [at] charterinternet.com> >To: Ca… [at] yahoogroups.com >Sent: Mon, August 30, 2010 9:15:46 AM >Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. > > >wirelessmonster wrote: > >> >>I don't know about the safety aspect compared to the main halyard, but when my >>main was fouled I went up the mast with the spinnaker halyard since we have >>roller furling on the jib. It worked, but who knows how safe it was. >> My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. Chris Campbell > > >__________ Information from ESET NOD32 Antivirus, version of virus signature >database 5409 (20100830) __________ > >The message was checked by ESET NOD32 Antivirus. > >http://www.eset.com > __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

If a 100 pound weight is lifted on a halyard the force on the halyard is 100 pounds If a block and tackle is attached to the hoist and the block and tackle is used to lift the load the force on the halyard is 100 pounds plus the weight of the block and tackle. If there is only one block there is no advantage to those doing the hoisting and the force on the single block is 200 pounds If there are four blocks and a becket giving a mechanical advantage of 3 to 1 those lifting will have to pull 33 pounds, the halyard still has 100 pounds of force, the connection between the weight and the first block has a force of 100 pounds, the last block (assuming four independent blocks has 66 pounds of force and .... Just drop the mast the sheave is probably frozen and the shaft goes through both the main and the genoa sheaves and the genoa halyard on a roller furler is probably so chafed that it will fail and the 100 pound weight will make a big mess on the deck. John B _____ From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of John Courter Sent: Monday, August 30, 2010 5:47 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. It actually increases load on the halyard. Taking the simplest case, a block hoisted up on the halyard gets you no advantage, but if you're lifting 100 lbs, then there is 100 lbs of load on each part adding to 200 lbs of load on the halyard supporting the block. John _____ From: Mark Alan Stahnke (MAS Consulting) <ma… [at] cox.net> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 11:47:05 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  When we go up the mast we use a halyard to hoist up a 3:1 tackle then run that thru a winch...Its much faster and reduces the load on the halyard and sheave. Mark From: John Courter <mailto:ca… [at] yahoo.com> To: Ca… [at] yahoogroups.com Sent: Monday, August 30, 2010 9:36 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Why can't you unroll the jib, lower it then use the jib halyard? You can then use the spin halyard as the safety backup. John _____ From: Chris Campbell <cl… [at] charterinternet.com> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 9:15:46 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. wirelessmonster wrote: I don't know about the safety aspect compared to the main halyard, but when my main was fouled I went up the mast with the spinnaker halyard since we have roller furling on the jib. It worked, but who knows how safe it was. My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. Chris Campbell __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com <http://www.eset.com/>

Hang on a minute. If there is a 100 lb weight at the end of a line passed through a block aloft and I pull on that line with enough force to lift the weight (100 lbs) then there is twice the original 100 lbs. Yes? No? Regards, Wayne From: John Boyce <je… [at] gmail.com> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 8:41:59 PM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  If a 100 pound weight is lifted on a halyard the force on the halyard is 100 pounds If a block and tackle is attached to the hoist and the block and tackle is used to lift the load the force on the halyard is 100 pounds plus the weight of the block and tackle. If there is only one block there is no advantage to those doing the hoisting and the force on the single block is 200 pounds If there are four blocks and a becket giving a mechanical advantage of 3 to 1 those lifting will have to pull 33 pounds, the halyard still has 100 pounds of force, the connection between the weight and the first block has a force of 100 pounds, the last block (assuming four independent blocks has 66 pounds of force and .... Just drop the mast the sheave is probably frozen and the shaft goes through both the main and the genoa sheaves and the genoa halyard on a roller furler is probably so chafed that it will fail and the 100 pound weight will make a big mess on the deck. John B From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of John Courter Sent: Monday, August 30, 2010 5:47 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. It actually increases load on the halyard. Taking the simplest case, a block hoisted up on the halyard gets you no advantage, but if you're lifting 100 lbs, then there is 100 lbs of load on each part adding to 200 lbs of load on the halyard supporting the block. John From: Mark Alan Stahnke (MAS Consulting) <ma… [at] cox.net> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 11:47:05 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  When we go up the mast we use a halyard to hoist up a 3:1 tackle then run that thru a winch...Its much faster and reduces the load on the halyard and sheave. Mark >From: John Courter >To: Ca… [at] yahoogroups.com >Sent: Monday, August 30, 2010 9:36 AM >Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. > > >Why can't you unroll the jib, lower it then use the jib halyard? You can >then use the spin halyard as the safety backup. > >John > > > > From: Chris Campbell <cl… [at] charterinternet.com> >To: Ca… [at] yahoogroups.com >Sent: Mon, August 30, 2010 9:15:46 AM >Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of >mast. > > >wirelessmonster wrote: > >> >>I don't know about the safety aspect compared to the main halyard, but when >>my main was fouled I went up the mast with the spinnaker halyard since we >>have roller furling on the jib. It worked, but who knows how safe it was. >> My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. Chris Campbell > > >__________ Information from ESET NOD32 Antivirus, version of virus signature >database 5409 (20100830) __________ > >The message was checked by ESET NOD32 Antivirus. > >http://www.eset.com > __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

How it works [cid:image001.png@01CB48DD.D8875070]<http://en.wikipedia.org/wiki/File:Pulley0.svg> Diagram 1 - A basic equation for a pulley: In equilibrium, the force F on the pulley axle is equal and opposite to the sum of the tensions<http://en.wikipedia.org/wiki/Tension_(mechanics)> in each line leaving the pulley, and these tensions are equal. [cid:image002.png@01CB48DD.D8875070]<http://en.wikipedia.org/wiki/File:Pulley1.svg> Diagram 2 - A simple pulley system - a single movable pulley lifting weight W. The tension in each line is W/2, yielding an advantage of 2. [cid:image003.png@01CB48DD.D8875070]<http://en.wikipedia.org/wiki/File:Pulley1a.svg> Diagram 2a - Another simple pulley system similar to diagram 2, but in which the lifting force is redirected downward. [cid:image004.jpg@01CB48DD.D8875070]<http://en.wikipedia.org/wiki/File:Polispasto2B.jpg> A practical compound pulley corresponding to diagram 2a [cid:image005.png@01CB48DD.D8875070]<http://en.wikipedia.org/wiki/File:Pulley2.svg> Diagram 3 - A simple compound pulley system: a movable pulley and a fixed pulley lifting weight W. The tension in each line is W/3, yielding an advantage of 3. [cid:image006.png@01CB48DD.D8875070]<http://en.wikipedia.org/wiki/File:Pulley2a.svg> Diagram 3a - A simple compound pulley system: a movable pulley and a fixed pulley lifting weight W, with an additional pulley redirecting the lifting force downward. The tension in each line is W/3, yielding an advantage of 3. [cid:image007.png@01CB48DD.D8875070]<http://en.wikipedia.org/wiki/File:Pulley3a.svg> Diagram 4a - A more complicated compound pulley system. The tension in each line is W/4, yielding an advantage of 4. An additional pulley redirecting the lifting force has been added. [cid:image008.jpg@01CB48DD.D8875070]<http://en.wikipedia.org/wiki/File:Polispasto4.jpg> Figure 4b - A practical block and tackle pulley system corresponding to diagram 4a. Note that the axles of the fixed and movable pulleys have been combined. From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Wayne Gillikin Sent: Tuesday, August 31, 2010 6:32 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Hang on a minute. If there is a 100 lb weight at the end of a line passed through a block aloft and I pull on that line with enough force to lift the weight (100 lbs) then there is twice the original 100 lbs. Yes? No? Regards, Wayne From: John Boyce <je… [at] gmail.com> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 8:41:59 PM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  If a 100 pound weight is lifted on a halyard the force on the halyard is 100 pounds If a block and tackle is attached to the hoist and the block and tackle is used to lift the load the force on the halyard is 100 pounds plus the weight of the block and tackle. If there is only one block there is no advantage to those doing the hoisting and the force on the single block is 200 pounds If there are four blocks and a becket giving a mechanical advantage of 3 to 1 those lifting will have to pull 33 pounds, the halyard still has 100 pounds of force, the connection between the weight and the first block has a force of 100 pounds, the last block (assuming four independent blocks has 66 pounds of force and .... Just drop the mast the sheave is probably frozen and the shaft goes through both the main and the genoa sheaves and the genoa halyard on a roller furler is probably so chafed that it will fail and the 100 pound weight will make a big mess on the deck. John B From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of John Courter Sent: Monday, August 30, 2010 5:47 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. It actually increases load on the halyard. Taking the simplest case, a block hoisted up on the halyard gets you no advantage, but if you're lifting 100 lbs, then there is 100 lbs of load on each part adding to 200 lbs of load on the halyard supporting the block. John From: Mark Alan Stahnke (MAS Consulting) <ma… [at] cox.net> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 11:47:05 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  When we go up the mast we use a halyard to hoist up a 3:1 tackle then run that thru a winch...Its much faster and reduces the load on the halyard and sheave. Mark From: John Courter<mailto:ca… [at] yahoo.com> To: Ca… [at] yahoogroups.com<mailto:Ca… [at] yahoogroups.com> Sent: Monday, August 30, 2010 9:36 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Why can't you unroll the jib, lower it then use the jib halyard? You can then use the spin halyard as the safety backup. John From: Chris Campbell <cl… [at] charterinternet.com<mailto:cl… [at] charterinternet.com>> To: Ca… [at] yahoogroups.com<mailto:Ca… [at] yahoogroups.com> Sent: Mon, August 30, 2010 9:15:46 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. wirelessmonster wrote: I don't know about the safety aspect compared to the main halyard, but when my main was fouled I went up the mast with the spinnaker halyard since we have roller furling on the jib. It worked, but who knows how safe it was. My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. Chris Campbell __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com<http://www.eset.com/>

Ok, so maybe it does not reduce the load on the masthead sheave but I do state that the physical effort is significantly reduce by first hoisting a 3:1. I got the idea watching the rigger fly up the mast with the aid of his assistant. Not being as young as the assistant, I rigged the same 3:1 but thru a winch and grinding was so much easier than the prior method of halyard thru the same winch. I guess I assumed that there would be reduced stress on the masthead sheave. Mark ----- Original Message ----- From: ti… [at] ch2m.com To: Ca… [at] yahoogroups.com Sent: Tuesday, August 31, 2010 7:26 AM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Wikipedia How it works Diagram 1 - A basic equation for a pulley: In equilibrium, the force F on the pulley axle is equal and opposite to the sum of the tensions in each line leaving the pulley, and these tensions are equal. Diagram 2 - A simple pulley system - a single movable pulley lifting weight W. The tension in each line is W/2, yielding an advantage of 2. Diagram 2a - Another simple pulley system similar to diagram 2, but in which the lifting force is redirected downward. A practical compound pulley corresponding to diagram 2a Diagram 3 - A simple compound pulley system: a movable pulley and a fixed pulley lifting weight W. The tension in each line is W/3, yielding an advantage of 3. Diagram 3a - A simple compound pulley system: a movable pulley and a fixed pulley lifting weight W, with an additional pulley redirecting the lifting force downward. The tension in each line is W/3, yielding an advantage of 3. Diagram 4a - A more complicated compound pulley system. The tension in each line is W/4, yielding an advantage of 4. An additional pulley redirecting the lifting force has been added. Figure 4b - A practical block and tackle pulley system corresponding to diagram 4a. Note that the axles of the fixed and movable pulleys have been combined. From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Wayne Gillikin Sent: Tuesday, August 31, 2010 6:32 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Hang on a minute. If there is a 100 lb weight at the end of a line passed through a block aloft and I pull on that line with enough force to lift the weight (100 lbs) then there is twice the original 100 lbs. Yes? No? Regards, Wayne ------------------------------------------------------------------------------ From: John Boyce <je… [at] gmail.com> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 8:41:59 PM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  If a 100 pound weight is lifted on a halyard the force on the halyard is 100 pounds If a block and tackle is attached to the hoist and the block and tackle is used to lift the load the force on the halyard is 100 pounds plus the weight of the block and tackle. If there is only one block there is no advantage to those doing the hoisting and the force on the single block is 200 pounds If there are four blocks and a becket giving a mechanical advantage of 3 to 1 those lifting will have to pull 33 pounds, the halyard still has 100 pounds of force, the connection between the weight and the first block has a force of 100 pounds, the last block (assuming four independent blocks has 66 pounds of force and .... Just drop the mast the sheave is probably frozen and the shaft goes through both the main and the genoa sheaves and the genoa halyard on a roller furler is probably so chafed that it will fail and the 100 pound weight will make a big mess on the deck. John B ------------------------------------------------------------------------------ From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of John Courter Sent: Monday, August 30, 2010 5:47 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. It actually increases load on the halyard. Taking the simplest case, a block hoisted up on the halyard gets you no advantage, but if you're lifting 100 lbs, then there is 100 lbs of load on each part adding to 200 lbs of load on the halyard supporting the block. John ------------------------------------------------------------------------------ From: Mark Alan Stahnke (MAS Consulting) <ma… [at] cox.net> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 11:47:05 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  When we go up the mast we use a halyard to hoist up a 3:1 tackle then run that thru a winch...Its much faster and reduces the load on the halyard and sheave. Mark ----- Original Message ----- From: John Courter To: Ca… [at] yahoogroups.com Sent: Monday, August 30, 2010 9:36 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Why can't you unroll the jib, lower it then use the jib halyard? You can then use the spin halyard as the safety backup. John ---------------------------------------------------------------------------- From: Chris Campbell <cl… [at] charterinternet.com> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 9:15:46 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. wirelessmonster wrote: I don't know about the safety aspect compared to the main halyard, but when my main was fouled I went up the mast with the spinnaker halyard since we have roller furling on the jib. It worked, but who knows how safe it was. My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. Chris Campbell __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 5412 (20100831) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

In Tim's first diagram it seems that the load on the block is only F (the weight suspended from it) and the load on each line is F/2. But how does that square with this info from the Harken site (http://www.harken.com/charts/blockloadvangle.php). Isn't this saying that the load on the block is twice the force/weight? Does the issue of equilibrium have anything to do with it? So, if the weight is simply hanging there it distributes its weight evenly between the two lines and the block only experiences the force of the weight. However, it if I need to raise the weight then I have to apply additional force? Does that make any sense? I am not even close to an engineer so please keep your explanation simple. I genuinely don't understand this and find it extremely puzzling. BLOCK LOADING VS ANGLE OF DEFLECTION Load on a block is a combination of the load on the line passing through the block, plus a block-loading factor, which is determined by the angle by which the block turns the sheet . For example, a footblock that turns a sheet 180° will see a load equal to twice the load on the sheet. A deck organizer, which turns a halyard only 30°, will see just 52% of the load on the halyard. Angle of deflection Load factor Angle of Deflection Load factor 30° 52% 120° 173% 45° 76% 135° 185% 60° 100% 150° 193% 75° 122% 160° 197% 90° 141% 180° 200% 105° 159% Copyright© 2010 Harken, Inc. All rights reserved If you would like to link to or reprint this article please contact Brownie Lewis From: "ti… [at] ch2m.com" <ti… [at] ch2m.com> To: Ca… [at] yahoogroups.com Sent: Tue, August 31, 2010 10:26:37 AM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Wikipedia How it works Diagram 1 - A basic equation for a pulley: In equilibrium, the force F on the pulley axle is equal and opposite to the sum of the tensions in each line leaving the pulley, and these tensions are equal. Diagram 2 - A simple pulley system - a single movable pulley lifting weight W. The tension in each line is W/2, yielding an advantage of 2. Diagram 2a - Another simple pulley system similar to diagram 2, but in which the lifting force is redirected downward. A practical compound pulley corresponding to diagram 2a Diagram 3 - A simple compound pulley system: a movable pulley and a fixed pulley lifting weight W. The tension in each line is W/3, yielding an advantage of 3. Diagram 3a - A simple compound pulley system: a movable pulley and a fixed pulley lifting weight W, with an additional pulley redirecting the lifting force downward. The tension in each line is W/3, yielding an advantage of 3. Diagram 4a - A more complicated compound pulley system. The tension in each line is W/4, yielding an advantage of 4. An additional pulley redirecting the lifting force has been added. Figure 4b - A practical block and tackle pulley system corresponding to diagram 4a. Note that the axles of the fixed and movable pulleys have been combined. From:Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Wayne Gillikin Sent: Tuesday, August 31, 2010 6:32 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Hang on a minute. If there is a 100 lb weight at the end of a line passed through a block aloft and I pull on that line with enough force to lift the weight (100 lbs) then there is twice the original 100 lbs. Yes? No? Regards, Wayne From:John Boyce <je… [at] gmail.com> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 8:41:59 PM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  If a 100 pound weight is lifted on a halyard the force on the halyard is 100 pounds If a block and tackle is attached to the hoist and the block and tackle is used to lift the load the force on the halyard is 100 pounds plus the weight of the block and tackle. If there is only one block there is no advantage to those doing the hoisting and the force on the single block is 200 pounds If there are four blocks and a becket giving a mechanical advantage of 3 to 1 those lifting will have to pull 33 pounds, the halyard still has 100 pounds of force, the connection between the weight and the first block has a force of 100 pounds, the last block (assuming four independent blocks has 66 pounds of force and .... Just drop the mast the sheave is probably frozen and the shaft goes through both the main and the genoa sheaves and the genoa halyard on a roller furler is probably so chafed that it will fail and the 100 pound weight will make a big mess on the deck. John B From:Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of John Courter Sent: Monday, August 30, 2010 5:47 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. It actually increases load on the halyard. Taking the simplest case, a block hoisted up on the halyard gets you no advantage, but if you're lifting 100 lbs, then there is 100 lbs of load on each part adding to 200 lbs of load on the halyard supporting the block. John From:Mark Alan Stahnke (MAS Consulting) <ma… [at] cox.net> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 11:47:05 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  When we go up the mast we use a halyard to hoist up a 3:1 tackle then run that thru a winch...Its much faster and reduces the load on the halyard and sheave. Mark >From:John Courter >To:Ca… [at] yahoogroups.com >Sent:Monday, August 30, 2010 9:36 AM >Subject:Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. > > >Why can't you unroll the jib, lower it then use the jib halyard? You can then >use the spin halyard as the safety backup. > >John > > >From:Chris Campbell <cl… [at] charterinternet.com> >To: Ca… [at] yahoogroups.com >Sent: Mon, August 30, 2010 9:15:46 AM >Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. > > >wirelessmonster wrote: > >> >>I don't know about the safety aspect compared to the main halyard, but when my >>main was fouled I went up the mast with the spinnaker halyard since we have >>roller furling on the jib. It worked, but who knows how safe it was. My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. Chris Campbell > > > >__________ Information from ESET NOD32 Antivirus, version of virus signature >database 5409 (20100830) __________ > >The message was checked by ESET NOD32 Antivirus. > >http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

Simple read the part in the Harken Manual: “load equal to twice the load on the sheet…” It is the first diagram “backwards” the sheet load is L/2… so at 90 degree loading, the load to hold the block is twice the sheet load. [cid:image001.png@01CB48E4.172D01C0] <http://en.wikipedia.org/wiki/File:Pulley0.svg> From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Wayne Gillikin Sent: Tuesday, August 31, 2010 8:07 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. (Harken) In Tim's first diagram it seems that the load on the block is only F (the weight suspended from it) and the load on each line is F/2. But how does that square with this info from the Harken site (http://www.harken.com/charts/blockloadvangle.php). Isn't this saying that the load on the block is twice the force/weight? Does the issue of equilibrium have anything to do with it? So, if the weight is simply hanging there it distributes its weight evenly between the two lines and the block only experiences the force of the weight. However, it if I need to raise the weight then I have to apply additional force? Does that make any sense? I am not even close to an engineer so please keep your explanation simple. I genuinely don't understand this and find it extremely puzzling. BLOCK LOADING VS ANGLE OF DEFLECTION [http://www.harken.com/images/load-angle.gif]Load on a block is a combination of the load on the line passing through the block, plus a block-loading factor, which is determined by the angle by which the block turns the sheet . For example, a footblock that turns a sheet 180° will see a load equal to twice the load on the sheet. A deck organizer, which turns a halyard only 30°, will see just 52% of the load on the halyard. Angle of deflection Load factor Angle of Deflection Load factor 30° 52% 120° 173% 45° 76% 135° 185% 60° 100% 150° 193% 75° 122% 160° 197% 90° 141% 180° 200% 105° 159% Copyright© 2010 Harken, Inc. All rights reserved If you would like to link to or reprint this article please contact Brownie Lewis<http://harken.com/email/HarkenAdvertising.aspx> From: "ti… [at] ch2m.com" <ti… [at] ch2m.com> To: Ca… [at] yahoogroups.com Sent: Tue, August 31, 2010 10:26:37 AM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Wikipedia How it works [cid:image001.png@01CB48E4.172D01C0]<http://en.wikipedia.org/wiki/File:Pulley0.svg> Diagram 1 - A basic equation for a pulley: In equilibrium, the force F on the pulley axle is equal and opposite to the sum of the tensions<http://en.wikipedia.org/wiki/Tension_(mechanics)> in each line leaving the pulley, and these tensions are equal. [cid:image002.png@01CB48E4.172D01C0]<http://en.wikipedia.org/wiki/File:Pulley1.svg> Diagram 2 - A simple pulley system - a single movable pulley lifting weight W. The tension in each line is W/2, yielding an advantage of 2. [cid:image003.png@01CB48E4.172D01C0]<http://en.wikipedia.org/wiki/File:Pulley1a.svg> Diagram 2a - Another simple pulley system similar to diagram 2, but in which the lifting force is redirected downward. [cid:image004.jpg@01CB48E4.172D01C0]<http://en.wikipedia.org/wiki/File:Polispasto2B.jpg> A practical compound pulley corresponding to diagram 2a [cid:image005.png@01CB48E4.172D01C0]<http://en.wikipedia.org/wiki/File:Pulley2.svg> Diagram 3 - A simple compound pulley system: a movable pulley and a fixed pulley lifting weight W. The tension in each line is W/3, yielding an advantage of 3. [cid:image006.png@01CB48E4.172D01C0]<http://en.wikipedia.org/wiki/File:Pulley2a.svg> Diagram 3a - A simple compound pulley system: a movable pulley and a fixed pulley lifting weight W, with an additional pulley redirecting the lifting force downward. The tension in each line is W/3, yielding an advantage of 3. [cid:image007.png@01CB48E4.172D01C0]<http://en.wikipedia.org/wiki/File:Pulley3a.svg> Diagram 4a - A more complicated compound pulley system. The tension in each line is W/4, yielding an advantage of 4. An additional pulley redirecting the lifting force has been added. [cid:image008.jpg@01CB48E4.172D01C0]<http://en.wikipedia.org/wiki/File:Polispasto4.jpg> Figure 4b - A practical block and tackle pulley system corresponding to diagram 4a. Note that the axles of the fixed and movable pulleys have been combined. From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Wayne Gillikin Sent: Tuesday, August 31, 2010 6:32 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Hang on a minute. If there is a 100 lb weight at the end of a line passed through a block aloft and I pull on that line with enough force to lift the weight (100 lbs) then there is twice the original 100 lbs. Yes? No? Regards, Wayne From: John Boyce <je… [at] gmail.com> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 8:41:59 PM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  If a 100 pound weight is lifted on a halyard the force on the halyard is 100 pounds If a block and tackle is attached to the hoist and the block and tackle is used to lift the load the force on the halyard is 100 pounds plus the weight of the block and tackle. If there is only one block there is no advantage to those doing the hoisting and the force on the single block is 200 pounds If there are four blocks and a becket giving a mechanical advantage of 3 to 1 those lifting will have to pull 33 pounds, the halyard still has 100 pounds of force, the connection between the weight and the first block has a force of 100 pounds, the last block (assuming four independent blocks has 66 pounds of force and .... Just drop the mast the sheave is probably frozen and the shaft goes through both the main and the genoa sheaves and the genoa halyard on a roller furler is probably so chafed that it will fail and the 100 pound weight will make a big mess on the deck. John B From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of John Courter Sent: Monday, August 30, 2010 5:47 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. It actually increases load on the halyard. Taking the simplest case, a block hoisted up on the halyard gets you no advantage, but if you're lifting 100 lbs, then there is 100 lbs of load on each part adding to 200 lbs of load on the halyard supporting the block. John From: Mark Alan Stahnke (MAS Consulting) <ma… [at] cox.net> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 11:47:05 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  When we go up the mast we use a halyard to hoist up a 3:1 tackle then run that thru a winch...Its much faster and reduces the load on the halyard and sheave. Mark From: John Courter<mailto:ca… [at] yahoo.com> To: Ca… [at] yahoogroups.com<mailto:Ca… [at] yahoogroups.com> Sent: Monday, August 30, 2010 9:36 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Why can't you unroll the jib, lower it then use the jib halyard? You can then use the spin halyard as the safety backup. John From: Chris Campbell <cl… [at] charterinternet.com<mailto:cl… [at] charterinternet.com>> To: Ca… [at] yahoogroups.com<mailto:Ca… [at] yahoogroups.com> Sent: Mon, August 30, 2010 9:15:46 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. wirelessmonster wrote: I don't know about the safety aspect compared to the main halyard, but when my main was fouled I went up the mast with the spinnaker halyard since we have roller furling on the jib. It worked, but who knows how safe it was. My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. Chris Campbell __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com<http://www.eset.com/>

Thanks, Tim. Please bear with me for a (hopefully) final question. Are you saying that the load on a line without any deflection is simply the load and when you deflect the line 180 degrees around a block the load on the line on each side of the block is halved so the load on the block is still only the original load on the undeflected line? So the load factor is increasing with deflection but the load is being shared by the lines and is decreasing? I thought the Harken example was saying that if you calculated the force on a sail and you took the sheet through a block that turned it 180 degrees you had twice the force on the block. You're saying I was completely misreading the Harken chart. Back to the drawing board! Regards, Wayne From: "ti… [at] ch2m.com" <ti… [at] ch2m.com> To: Ca… [at] yahoogroups.com Sent: Tue, August 31, 2010 11:11:23 AM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. (Harken) Simple read the part in the Harken Manual: “load equal to twice the load on the sheet…” It is the first diagram “backwards” the sheet load is L/2… so at 90 degree loading, the load to hold the block is twice the sheet load. From:Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Wayne Gillikin Sent: Tuesday, August 31, 2010 8:07 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. (Harken) In Tim's first diagram it seems that the load on the block is only F (the weight suspended from it) and the load on each line is F/2. But how does that square with this info from the Harken site (http://www.harken.com/charts/blockloadvangle.php). Isn't this saying that the load on the block is twice the force/weight? Does the issue of equilibrium have anything to do with it? So, if the weight is simply hanging there it distributes its weight evenly between the two lines and the block only experiences the force of the weight. However, it if I need to raise the weight then I have to apply additional force? Does that make any sense? I am not even close to an engineer so please keep your explanation simple. I genuinely don't understand this and find it extremely puzzling. BLOCK LOADING VS ANGLE OF DEFLECTION Load on a block is a combination of the load on the line passing through the block, plus a block-loading factor, which is determined by the angle by which the block turns the sheet . For example, a footblock that turns a sheet 180° will see a load equal to twice the load on the sheet. A deck organizer, which turns a halyard only 30°, will see just 52% of the load on the halyard. Angle of deflection Load factor Angle of Deflection Load factor 30° 52% 120° 173% 45° 76% 135° 185% 60° 100% 150° 193% 75° 122% 160° 197% 90° 141% 180° 200% 105° 159% Copyright© 2010 Harken, Inc. All rights reserved If you would like to link to or reprint this article please contact Brownie Lewis From:"ti… [at] ch2m.com" <ti… [at] ch2m.com> To: Ca… [at] yahoogroups.com Sent: Tue, August 31, 2010 10:26:37 AM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Wikipedia How it works Diagram 1 - A basic equation for a pulley: In equilibrium, the force F on the pulley axle is equal and opposite to the sum of the tensions in each line leaving the pulley, and these tensions are equal. Diagram 2 - A simple pulley system - a single movable pulley lifting weight W. The tension in each line is W/2, yielding an advantage of 2. Diagram 2a - Another simple pulley system similar to diagram 2, but in which the lifting force is redirected downward. A practical compound pulley corresponding to diagram 2a Diagram 3 - A simple compound pulley system: a movable pulley and a fixed pulley lifting weight W. The tension in each line is W/3, yielding an advantage of 3. Diagram 3a - A simple compound pulley system: a movable pulley and a fixed pulley lifting weight W, with an additional pulley redirecting the lifting force downward. The tension in each line is W/3, yielding an advantage of 3. Diagram 4a - A more complicated compound pulley system. The tension in each line is W/4, yielding an advantage of 4. An additional pulley redirecting the lifting force has been added. Figure 4b - A practical block and tackle pulley system corresponding to diagram 4a. Note that the axles of the fixed and movable pulleys have been combined. From:Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Wayne Gillikin Sent: Tuesday, August 31, 2010 6:32 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Hang on a minute. If there is a 100 lb weight at the end of a line passed through a block aloft and I pull on that line with enough force to lift the weight (100 lbs) then there is twice the original 100 lbs. Yes? No? Regards, Wayne From:John Boyce <je… [at] gmail.com> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 8:41:59 PM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  If a 100 pound weight is lifted on a halyard the force on the halyard is 100 pounds If a block and tackle is attached to the hoist and the block and tackle is used to lift the load the force on the halyard is 100 pounds plus the weight of the block and tackle. If there is only one block there is no advantage to those doing the hoisting and the force on the single block is 200 pounds If there are four blocks and a becket giving a mechanical advantage of 3 to 1 those lifting will have to pull 33 pounds, the halyard still has 100 pounds of force, the connection between the weight and the first block has a force of 100 pounds, the last block (assuming four independent blocks has 66 pounds of force and .... Just drop the mast the sheave is probably frozen and the shaft goes through both the main and the genoa sheaves and the genoa halyard on a roller furler is probably so chafed that it will fail and the 100 pound weight will make a big mess on the deck. John B From:Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of John Courter Sent: Monday, August 30, 2010 5:47 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. It actually increases load on the halyard. Taking the simplest case, a block hoisted up on the halyard gets you no advantage, but if you're lifting 100 lbs, then there is 100 lbs of load on each part adding to 200 lbs of load on the halyard supporting the block. John From:Mark Alan Stahnke (MAS Consulting) <ma… [at] cox.net> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 11:47:05 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  When we go up the mast we use a halyard to hoist up a 3:1 tackle then run that thru a winch...Its much faster and reduces the load on the halyard and sheave. Mark >From:John Courter >To:Ca… [at] yahoogroups.com >Sent:Monday, August 30, 2010 9:36 AM >Subject:Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. > > >Why can't you unroll the jib, lower it then use the jib halyard? You can then >use the spin halyard as the safety backup. > >John > > >From:Chris Campbell <cl… [at] charterinternet.com> >To: Ca… [at] yahoogroups.com >Sent: Mon, August 30, 2010 9:15:46 AM >Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. > > >wirelessmonster wrote: > >> >>I don't know about the safety aspect compared to the main halyard, but when my >>main was fouled I went up the mast with the spinnaker halyard since we have >>roller furling on the jib. It worked, but who knows how safe it was. My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. Chris Campbell > > > >__________ Information from ESET NOD32 Antivirus, version of virus signature >database 5409 (20100830) __________ > >The message was checked by ESET NOD32 Antivirus. > >http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

For the Harken table you must think relative to the force on the strap holding the block to the deck or whatever the attachment point is. Picture the block attached to a spring scale that measures how much pull there is on the attachment. [L] = load O = block --- =line (^) = scale If [L]----------O----------->100lbs (^) 0lbs (Harken point of reference) Load/line straight with the block, then the scale would read zero “the line does not touch the block” so at zero angle the force on the block is - nothing. If as below the F/2 = the sheet load is [SL]… so [SL] times two = F - or as Harken has said F= 200% (2x) the [SL] [cid:image001.png@01CB48EB.7340C490]<http://en.wikipedia.org/wiki/File:Pulley0.svg> (^) = 2x line load or 200% line load = full force/weight. F=100lbs F/2=50lbs 2x50=100lbs From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Wayne Gillikin Sent: Tuesday, August 31, 2010 8:56 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. (Harken) Thanks, Tim. Please bear with me for a (hopefully) final question. Are you saying that the load on a line without any deflection is simply the load and when you deflect the line 180 degrees around a block the load on the line on each side of the block is halved so the load on the block is still only the original load on the undeflected line? So the load factor is increasing with deflection but the load is being shared by the lines and is decreasing? I thought the Harken example was saying that if you calculated the force on a sail and you took the sheet through a block that turned it 180 degrees you had twice the force on the block. You're saying I was completely misreading the Harken chart. Back to the drawing board! Regards, Wayne From: "ti… [at] ch2m.com" <ti… [at] ch2m.com> To: Ca… [at] yahoogroups.com Sent: Tue, August 31, 2010 11:11:23 AM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. (Harken) Simple read the part in the Harken Manual: “load equal to twice the load on the sheet…” It is the first diagram “backwards” the sheet load is L/2… so at 90 degree loading, the load to hold the block is twice the sheet load. [cid:image001.png@01CB48EB.7340C490] <http://en.wikipedia.org/wiki/File:Pulley0.svg> From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Wayne Gillikin Sent: Tuesday, August 31, 2010 8:07 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. (Harken) In Tim's first diagram it seems that the load on the block is only F (the weight suspended from it) and the load on each line is F/2. But how does that square with this info from the Harken site (http://www.harken.com/charts/blockloadvangle.php). Isn't this saying that the load on the block is twice the force/weight? Does the issue of equilibrium have anything to do with it? So, if the weight is simply hanging there it distributes its weight evenly between the two lines and the block only experiences the force of the weight. However, it if I need to raise the weight then I have to apply additional force? Does that make any sense? I am not even close to an engineer so please keep your explanation simple. I genuinely don't understand this and find it extremely puzzling. BLOCK LOADING VS ANGLE OF DEFLECTION [http://www.harken.com/images/load-angle.gif]Load on a block is a combination of the load on the line passing through the block, plus a block-loading factor, which is determined by the angle by which the block turns the sheet . For example, a footblock that turns a sheet 180° will see a load equal to twice the load on the sheet. A deck organizer, which turns a halyard only 30°, will see just 52% of the load on the halyard. Angle of deflection Load factor Angle of Deflection Load factor 30° 52% 120° 173% 45° 76% 135° 185% 60° 100% 150° 193% 75° 122% 160° 197% 90° 141% 180° 200% 105° 159% Copyright© 2010 Harken, Inc. All rights reserved If you would like to link to or reprint this article please contact Brownie Lewis<http://harken.com/email/HarkenAdvertising.aspx> From: "ti… [at] ch2m.com" <ti… [at] ch2m.com> To: Ca… [at] yahoogroups.com Sent: Tue, August 31, 2010 10:26:37 AM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Wikipedia How it works [cid:image001.png@01CB48EB.7340C490]<http://en.wikipedia.org/wiki/File:Pulley0.svg> Diagram 1 - A basic equation for a pulley: In equilibrium, the force F on the pulley axle is equal and opposite to the sum of the tensions<http://en.wikipedia.org/wiki/Tension_(mechanics)> in each line leaving the pulley, and these tensions are equal. [cid:image002.png@01CB48EB.7340C490]<http://en.wikipedia.org/wiki/File:Pulley1.svg> Diagram 2 - A simple pulley system - a single movable pulley lifting weight W. The tension in each line is W/2, yielding an advantage of 2. [cid:image003.png@01CB48EB.7340C490]<http://en.wikipedia.org/wiki/File:Pulley1a.svg> Diagram 2a - Another simple pulley system similar to diagram 2, but in which the lifting force is redirected downward. [cid:image004.jpg@01CB48EB.7340C490]<http://en.wikipedia.org/wiki/File:Polispasto2B.jpg> A practical compound pulley corresponding to diagram 2a [cid:image005.png@01CB48EB.7340C490]<http://en.wikipedia.org/wiki/File:Pulley2.svg> Diagram 3 - A simple compound pulley system: a movable pulley and a fixed pulley lifting weight W. The tension in each line is W/3, yielding an advantage of 3. [cid:image006.png@01CB48EB.7340C490]<http://en.wikipedia.org/wiki/File:Pulley2a.svg> Diagram 3a - A simple compound pulley system: a movable pulley and a fixed pulley lifting weight W, with an additional pulley redirecting the lifting force downward. The tension in each line is W/3, yielding an advantage of 3. [cid:image007.png@01CB48EB.7340C490]<http://en.wikipedia.org/wiki/File:Pulley3a.svg> Diagram 4a - A more complicated compound pulley system. The tension in each line is W/4, yielding an advantage of 4. An additional pulley redirecting the lifting force has been added. [cid:image008.jpg@01CB48EB.7340C490]<http://en.wikipedia.org/wiki/File:Polispasto4.jpg> Figure 4b - A practical block and tackle pulley system corresponding to diagram 4a. Note that the axles of the fixed and movable pulleys have been combined. From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Wayne Gillikin Sent: Tuesday, August 31, 2010 6:32 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Hang on a minute. If there is a 100 lb weight at the end of a line passed through a block aloft and I pull on that line with enough force to lift the weight (100 lbs) then there is twice the original 100 lbs. Yes? No? Regards, Wayne From: John Boyce <je… [at] gmail.com> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 8:41:59 PM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  If a 100 pound weight is lifted on a halyard the force on the halyard is 100 pounds If a block and tackle is attached to the hoist and the block and tackle is used to lift the load the force on the halyard is 100 pounds plus the weight of the block and tackle. If there is only one block there is no advantage to those doing the hoisting and the force on the single block is 200 pounds If there are four blocks and a becket giving a mechanical advantage of 3 to 1 those lifting will have to pull 33 pounds, the halyard still has 100 pounds of force, the connection between the weight and the first block has a force of 100 pounds, the last block (assuming four independent blocks has 66 pounds of force and .... Just drop the mast the sheave is probably frozen and the shaft goes through both the main and the genoa sheaves and the genoa halyard on a roller furler is probably so chafed that it will fail and the 100 pound weight will make a big mess on the deck. John B From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of John Courter Sent: Monday, August 30, 2010 5:47 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. It actually increases load on the halyard. Taking the simplest case, a block hoisted up on the halyard gets you no advantage, but if you're lifting 100 lbs, then there is 100 lbs of load on each part adding to 200 lbs of load on the halyard supporting the block. John From: Mark Alan Stahnke (MAS Consulting) <ma… [at] cox.net> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 11:47:05 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  When we go up the mast we use a halyard to hoist up a 3:1 tackle then run that thru a winch...Its much faster and reduces the load on the halyard and sheave. Mark From: John Courter<mailto:ca… [at] yahoo.com> To: Ca… [at] yahoogroups.com<mailto:Ca… [at] yahoogroups.com> Sent: Monday, August 30, 2010 9:36 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Why can't you unroll the jib, lower it then use the jib halyard? You can then use the spin halyard as the safety backup. John From: Chris Campbell <cl… [at] charterinternet.com<mailto:cl… [at] charterinternet.com>> To: Ca… [at] yahoogroups.com<mailto:Ca… [at] yahoogroups.com> Sent: Mon, August 30, 2010 9:15:46 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. wirelessmonster wrote: I don't know about the safety aspect compared to the main halyard, but when my main was fouled I went up the mast with the spinnaker halyard since we have roller furling on the jib. It worked, but who knows how safe it was. My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. Chris Campbell __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com<http://www.eset.com/>

Wayne Gillikin wrote: > Thanks, Tim. > > Please bear with me for a (hopefully) final question. Are you saying > that the load on a line without any deflection is simply the load and > when you deflect the line 180 degrees around a block the load on the > line on each side of the block is halved so the load on the block is > still only the original load on the undeflected line? So the load > factor is increasing with deflection but the load is being shared by > the lines and is decreasing? As I see it, for static forces, the load on each line is halved and the total load on the block stays the same. You can distribute forces over more units, reducing the force on each, but can't multiply it. Chris Campbell

Thanks, Tim. Very illuminating. Regards, Wayne From: "ti… [at] ch2m.com" <ti… [at] ch2m.com> To: Ca… [at] yahoogroups.com Sent: Tue, August 31, 2010 12:16:26 PM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. (Harken) For the Harken table you must think relative to the force on the strap holding the block to the deck or whatever the attachment point is. Picture the block attached to a spring scale that measures how much pull there is on the attachment. [L] = load O = block --- =line (^) = scale If [L]----------O---------à100lbs (^) 0lbs (Harken point of reference) Load/line straight with the block, then the scale would read zero “the line does not touch the block” so at zero angle the force on the block is - nothing. If as below the F/2 = the sheet load is [SL]… so [SL] times two = F - or as Harken has said F= 200% (2x) the [SL] (^) = 2x line load or 200% line load = full force/weight. F=100lbs F/2=50lbs 2x50=100lbs From:Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Wayne Gillikin Sent: Tuesday, August 31, 2010 8:56 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. (Harken) Thanks, Tim. Please bear with me for a (hopefully) final question. Are you saying that the load on a line without any deflection is simply the load and when you deflect the line 180 degrees around a block the load on the line on each side of the block is halved so the load on the block is still only the original load on the undeflected line? So the load factor is increasing with deflection but the load is being shared by the lines and is decreasing? I thought the Harken example was saying that if you calculated the force on a sail and you took the sheet through a block that turned it 180 degrees you had twice the force on the block. You're saying I was completely misreading the Harken chart. Back to the drawing board! Regards, Wayne From:"ti… [at] ch2m.com" <ti… [at] ch2m.com> To: Ca… [at] yahoogroups.com Sent: Tue, August 31, 2010 11:11:23 AM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. (Harken) Simple read the part in the Harken Manual: “load equal to twice the load on the sheet…” It is the first diagram “backwards” the sheet load is L/2… so at 90 degree loading, the load to hold the block is twice the sheet load. From:Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Wayne Gillikin Sent: Tuesday, August 31, 2010 8:07 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. (Harken) In Tim's first diagram it seems that the load on the block is only F (the weight suspended from it) and the load on each line is F/2. But how does that square with this info from the Harken site (http://www.harken.com/charts/blockloadvangle.php). Isn't this saying that the load on the block is twice the force/weight? Does the issue of equilibrium have anything to do with it? So, if the weight is simply hanging there it distributes its weight evenly between the two lines and the block only experiences the force of the weight. However, it if I need to raise the weight then I have to apply additional force? Does that make any sense? I am not even close to an engineer so please keep your explanation simple. I genuinely don't understand this and find it extremely puzzling. BLOCK LOADING VS ANGLE OF DEFLECTION Load on a block is a combination of the load on the line passing through the block, plus a block-loading factor, which is determined by the angle by which the block turns the sheet . For example, a footblock that turns a sheet 180° will see a load equal to twice the load on the sheet. A deck organizer, which turns a halyard only 30°, will see just 52% of the load on the halyard. Angle of deflection Load factor Angle of Deflection Load factor 30° 52% 120° 173% 45° 76% 135° 185% 60° 100% 150° 193% 75° 122% 160° 197% 90° 141% 180° 200% 105° 159% Copyright© 2010 Harken, Inc. All rights reserved If you would like to link to or reprint this article please contact Brownie Lewis From:"ti… [at] ch2m.com" <ti… [at] ch2m.com> To: Ca… [at] yahoogroups.com Sent: Tue, August 31, 2010 10:26:37 AM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Wikipedia How it works Diagram 1 - A basic equation for a pulley: In equilibrium, the force F on the pulley axle is equal and opposite to the sum of the tensions in each line leaving the pulley, and these tensions are equal. Diagram 2 - A simple pulley system - a single movable pulley lifting weight W. The tension in each line is W/2, yielding an advantage of 2. Diagram 2a - Another simple pulley system similar to diagram 2, but in which the lifting force is redirected downward. A practical compound pulley corresponding to diagram 2a Diagram 3 - A simple compound pulley system: a movable pulley and a fixed pulley lifting weight W. The tension in each line is W/3, yielding an advantage of 3. Diagram 3a - A simple compound pulley system: a movable pulley and a fixed pulley lifting weight W, with an additional pulley redirecting the lifting force downward. The tension in each line is W/3, yielding an advantage of 3. Diagram 4a - A more complicated compound pulley system. The tension in each line is W/4, yielding an advantage of 4. An additional pulley redirecting the lifting force has been added. Figure 4b - A practical block and tackle pulley system corresponding to diagram 4a. Note that the axles of the fixed and movable pulleys have been combined. From:Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Wayne Gillikin Sent: Tuesday, August 31, 2010 6:32 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Hang on a minute. If there is a 100 lb weight at the end of a line passed through a block aloft and I pull on that line with enough force to lift the weight (100 lbs) then there is twice the original 100 lbs. Yes? No? Regards, Wayne From:John Boyce <je… [at] gmail.com> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 8:41:59 PM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  If a 100 pound weight is lifted on a halyard the force on the halyard is 100 pounds If a block and tackle is attached to the hoist and the block and tackle is used to lift the load the force on the halyard is 100 pounds plus the weight of the block and tackle. If there is only one block there is no advantage to those doing the hoisting and the force on the single block is 200 pounds If there are four blocks and a becket giving a mechanical advantage of 3 to 1 those lifting will have to pull 33 pounds, the halyard still has 100 pounds of force, the connection between the weight and the first block has a force of 100 pounds, the last block (assuming four independent blocks has 66 pounds of force and .... Just drop the mast the sheave is probably frozen and the shaft goes through both the main and the genoa sheaves and the genoa halyard on a roller furler is probably so chafed that it will fail and the 100 pound weight will make a big mess on the deck. John B From:Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of John Courter Sent: Monday, August 30, 2010 5:47 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. It actually increases load on the halyard. Taking the simplest case, a block hoisted up on the halyard gets you no advantage, but if you're lifting 100 lbs, then there is 100 lbs of load on each part adding to 200 lbs of load on the halyard supporting the block. John From:Mark Alan Stahnke (MAS Consulting) <ma… [at] cox.net> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 11:47:05 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  When we go up the mast we use a halyard to hoist up a 3:1 tackle then run that thru a winch...Its much faster and reduces the load on the halyard and sheave. Mark >From:John Courter >To:Ca… [at] yahoogroups.com >Sent:Monday, August 30, 2010 9:36 AM >Subject:Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. > > >Why can't you unroll the jib, lower it then use the jib halyard? You can then >use the spin halyard as the safety backup. > >John > > >From:Chris Campbell <cl… [at] charterinternet.com> >To: Ca… [at] yahoogroups.com >Sent: Mon, August 30, 2010 9:15:46 AM >Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. > > >wirelessmonster wrote: > >> >>I don't know about the safety aspect compared to the main halyard, but when my >>main was fouled I went up the mast with the spinnaker halyard since we have >>roller furling on the jib. It worked, but who knows how safe it was. My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. Chris Campbell > > > >__________ Information from ESET NOD32 Antivirus, version of virus signature >database 5409 (20100830) __________ > >The message was checked by ESET NOD32 Antivirus. > >http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

Given this situation and others, is one of the main reasons I want to install these (see below) on the mast ever 18". Mast steps (several sources and models available) http://www.thechandleryonline.com//product.asp?pf_id=054_A81000&dept_id=1717 With a good harness and safety rig, it is possible to do it yourself, both up and down using whatever lines are available on your vessel in any given situation. Given that fact that you are not indestructible, best done at dockside but can be done while on an anchor if you really have too. harnesses http://www.rei.com/search?query=harness&button.x=0&button.y=0 brakes (ascenders & descenders) http://www.rei.com/category/4500694 Combine that kit with a simple tool bag and your tools each on there own line tied to the bag your should be in good shape. Best /ch

Opps, it looks like I was too sleepy when I did this one. I'd still stick to the last line in my e-mail. _____ From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Wayne Gillikin Sent: Tuesday, August 31, 2010 8:32 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Hang on a minute. If there is a 100 lb weight at the end of a line passed through a block aloft and I pull on that line with enough force to lift the weight (100 lbs) then there is twice the original 100 lbs. Yes? No? Regards, Wayne _____ From: John Boyce <je… [at] gmail.com> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 8:41:59 PM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  If a 100 pound weight is lifted on a halyard the force on the halyard is 100 pounds If a block and tackle is attached to the hoist and the block and tackle is used to lift the load the force on the halyard is 100 pounds plus the weight of the block and tackle. If there is only one block there is no advantage to those doing the hoisting and the force on the single block is 200 pounds If there are four blocks and a becket giving a mechanical advantage of 3 to 1 those lifting will have to pull 33 pounds, the halyard still has 100 pounds of force, the connection between the weight and the first block has a force of 100 pounds, the last block (assuming four independent blocks has 66 pounds of force and .... Just drop the mast the sheave is probably frozen and the shaft goes through both the main and the genoa sheaves and the genoa halyard on a roller furler is probably so chafed that it will fail and the 100 pound weight will make a big mess on the deck. John B _____ From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of John Courter Sent: Monday, August 30, 2010 5:47 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. It actually increases load on the halyard. Taking the simplest case, a block hoisted up on the halyard gets you no advantage, but if you're lifting 100 lbs, then there is 100 lbs of load on each part adding to 200 lbs of load on the halyard supporting the block. John _____ From: Mark Alan Stahnke (MAS Consulting) <ma… [at] cox.net> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 11:47:05 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  When we go up the mast we use a halyard to hoist up a 3:1 tackle then run that thru a winch...Its much faster and reduces the load on the halyard and sheave. Mark From: John Courter <mailto:ca… [at] yahoo.com> To: Ca… [at] yahoogroups.com Sent: Monday, August 30, 2010 9:36 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Why can't you unroll the jib, lower it then use the jib halyard? You can then use the spin halyard as the safety backup. John _____ From: Chris Campbell <cl… [at] charterinternet.com> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 9:15:46 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. wirelessmonster wrote: I don't know about the safety aspect compared to the main halyard, but when my main was fouled I went up the mast with the spinnaker halyard since we have roller furling on the jib. It worked, but who knows how safe it was. My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. Chris Campbell __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com <http://www.eset.com/>

Delightful and even cute pictures, Timm. As far as the grinders go on a 3:1, they will have to pull three times as much line at 1/3 the force. And, of course, as one approaches the compressed end of the pulley arrangement, there is potential for binding. One could take the main sheet off boom/traveler and attach it to a halyard as a method for a person to jack themselves up the mast. Problem is that the main sheet might then have to be several hundred feet long depending on purchase arrangement. Advice to originator is "Take the mast down." It is, by the way, often difficult to fix stuff at the top of the mast while sitting there. Hard to reach hidden things, hang onto tools, and the like. So if the mast climber is not experienced, would be good for all below to wear hard hats. Even a screw can hurt when dropped from that height. Cheers Charlie From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of ti… [at] ch2m.com Sent: Tuesday, August 31, 2010 10:27 AM To: Ca… [at] yahoogroups.com Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Wikipedia How it works [cid:976055100@01092010-1CE5]<http://en.wikipedia.org/wiki/File:Pulley0.svg> Diagram 1 - A basic equation for a pulley: In equilibrium, the force F on the pulley axle is equal and opposite to the sum of the tensions<http://en.wikipedia.org/wiki/Tension_(mechanics)> in each line leaving the pulley, and these tensions are equal. [cid:976055100@01092010-1CEC]<http://en.wikipedia.org/wiki/File:Pulley1.svg> Diagram 2 - A simple pulley system - a single movable pulley lifting weight W. The tension in each line is W/2, yielding an advantage of 2. [cid:976055100@01092010-1CF3]<http://en.wikipedia.org/wiki/File:Pulley1a.svg> Diagram 2a - Another simple pulley system similar to diagram 2, but in which the lifting force is redirected downward. [cid:976055100@01092010-1CFA]<http://en.wikipedia.org/wiki/File:Polispasto2B.jpg> A practical compound pulley corresponding to diagram 2a [cid:976055100@01092010-1D01]<http://en.wikipedia.org/wiki/File:Pulley2.svg> Diagram 3 - A simple compound pulley system: a movable pulley and a fixed pulley lifting weight W. The tension in each line is W/3, yielding an advantage of 3. [cid:976055100@01092010-1D08]<http://en.wikipedia.org/wiki/File:Pulley2a.svg> Diagram 3a - A simple compound pulley system: a movable pulley and a fixed pulley lifting weight W, with an additional pulley redirecting the lifting force downward. The tension in each line is W/3, yielding an advantage of 3. [cid:976055100@01092010-1D0F]<http://en.wikipedia.org/wiki/File:Pulley3a.svg> Diagram 4a - A more complicated compound pulley system. The tension in each line is W/4, yielding an advantage of 4. An additional pulley redirecting the lifting force has been added. [cid:976055100@01092010-1D16]<http://en.wikipedia.org/wiki/File:Polispasto4.jpg> Figure 4b - A practical block and tackle pulley system corresponding to diagram 4a. Note that the axles of the fixed and movable pulleys have been combined. From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Wayne Gillikin Sent: Tuesday, August 31, 2010 6:32 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Hang on a minute. If there is a 100 lb weight at the end of a line passed through a block aloft and I pull on that line with enough force to lift the weight (100 lbs) then there is twice the original 100 lbs. Yes? No? Regards, Wayne From: John Boyce <je… [at] gmail.com> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 8:41:59 PM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  If a 100 pound weight is lifted on a halyard the force on the halyard is 100 pounds If a block and tackle is attached to the hoist and the block and tackle is used to lift the load the force on the halyard is 100 pounds plus the weight of the block and tackle. If there is only one block there is no advantage to those doing the hoisting and the force on the single block is 200 pounds If there are four blocks and a becket giving a mechanical advantage of 3 to 1 those lifting will have to pull 33 pounds, the halyard still has 100 pounds of force, the connection between the weight and the first block has a force of 100 pounds, the last block (assuming four independent blocks has 66 pounds of force and .... Just drop the mast the sheave is probably frozen and the shaft goes through both the main and the genoa sheaves and the genoa halyard on a roller furler is probably so chafed that it will fail and the 100 pound weight will make a big mess on the deck. John B From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of John Courter Sent: Monday, August 30, 2010 5:47 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. It actually increases load on the halyard. Taking the simplest case, a block hoisted up on the halyard gets you no advantage, but if you're lifting 100 lbs, then there is 100 lbs of load on each part adding to 200 lbs of load on the halyard supporting the block. John From: Mark Alan Stahnke (MAS Consulting) <ma… [at] cox.net> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 11:47:05 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  When we go up the mast we use a halyard to hoist up a 3:1 tackle then run that thru a winch...Its much faster and reduces the load on the halyard and sheave. Mark From: John Courter<mailto:ca… [at] yahoo.com> To: Ca… [at] yahoogroups.com<mailto:Ca… [at] yahoogroups.com> Sent: Monday, August 30, 2010 9:36 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Why can't you unroll the jib, lower it then use the jib halyard? You can then use the spin halyard as the safety backup. John From: Chris Campbell <cl… [at] charterinternet.com<mailto:cl… [at] charterinternet.com>> To: Ca… [at] yahoogroups.com<mailto:Ca… [at] yahoogroups.com> Sent: Mon, August 30, 2010 9:15:46 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. wirelessmonster wrote: I don't know about the safety aspect compared to the main halyard, but when my main was fouled I went up the mast with the spinnaker halyard since we have roller furling on the jib. It worked, but who knows how safe it was. My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. Chris Campbell __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com<http://www.eset.com/>

Wayne, think of it this way. As with all physics 101 items, we are assuming weightless, frictionless, low-cal lines and pulleys. There is some work to be done. That work is to raise (e.g.) a 100 lb weight up a 50 foot mast. Regardless of how you do it, that is the work to be done. Now let's put in the pulleys with three lines (3:1 purchase). Regardless of this intermediate rig, there is a weight of 100lb pulling at both the top and the bottom of the contraption. Work can be called a force applied through a distance. With the 3 line rig, your puller will have to pull 3 times as far to get the work done. But the total work is the same (a 100 lb weight up a 50 foot mast). Therefore the puller will have to pull 1/3 as hard for 3 times as long. Your puller has to pull in 150 feet of line to take the weight up the 50 foot mast. It seems easier because the puller has to pull only 1/3 as hard, but for a longer time. As far as the weight distribution goes, as I said above "Regardless of this intermediate rig, there is a weight of 100lb pulling at both the top and the bottom of the contraption." If there are three lines in between the top and bottom, they share that 100lb load equally, or about 33 lbs apiece. The pulley rigs are meant to reduce the instantaneous force required, but spread it over a longer time or distance. This why we old folks buy 2:1 and 3:1 winches. Don't have to pull as hard, but we have to pull longer - which overall seems easier. Cheers Charlie From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Wayne Gillikin Sent: Tuesday, August 31, 2010 9:32 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Hang on a minute. If there is a 100 lb weight at the end of a line passed through a block aloft and I pull on that line with enough force to lift the weight (100 lbs) then there is twice the original 100 lbs. Yes? No? Regards, Wayne From: John Boyce <je… [at] gmail.com> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 8:41:59 PM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  If a 100 pound weight is lifted on a halyard the force on the halyard is 100 pounds If a block and tackle is attached to the hoist and the block and tackle is used to lift the load the force on the halyard is 100 pounds plus the weight of the block and tackle. If there is only one block there is no advantage to those doing the hoisting and the force on the single block is 200 pounds If there are four blocks and a becket giving a mechanical advantage of 3 to 1 those lifting will have to pull 33 pounds, the halyard still has 100 pounds of force, the connection between the weight and the first block has a force of 100 pounds, the last block (assuming four independent blocks has 66 pounds of force and .... Just drop the mast the sheave is probably frozen and the shaft goes through both the main and the genoa sheaves and the genoa halyard on a roller furler is probably so chafed that it will fail and the 100 pound weight will make a big mess on the deck. John B From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of John Courter Sent: Monday, August 30, 2010 5:47 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. It actually increases load on the halyard. Taking the simplest case, a block hoisted up on the halyard gets you no advantage, but if you're lifting 100 lbs, then there is 100 lbs of load on each part adding to 200 lbs of load on the halyard supporting the block. John From: Mark Alan Stahnke (MAS Consulting) <ma… [at] cox.net> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 11:47:05 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  When we go up the mast we use a halyard to hoist up a 3:1 tackle then run that thru a winch...Its much faster and reduces the load on the halyard and sheave. Mark From: John Courter<mailto:ca… [at] yahoo.com> To: Ca… [at] yahoogroups.com<mailto:Ca… [at] yahoogroups.com> Sent: Monday, August 30, 2010 9:36 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Why can't you unroll the jib, lower it then use the jib halyard? You can then use the spin halyard as the safety backup. John From: Chris Campbell <cl… [at] charterinternet.com<mailto:cl… [at] charterinternet.com>> To: Ca… [at] yahoogroups.com<mailto:Ca… [at] yahoogroups.com> Sent: Mon, August 30, 2010 9:15:46 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. wirelessmonster wrote: I don't know about the safety aspect compared to the main halyard, but when my main was fouled I went up the mast with the spinnaker halyard since we have roller furling on the jib. It worked, but who knows how safe it was. My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. Chris Campbell __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com<http://www.eset.com/>

Nice explanation Charlie... Also know as.. "you don't get something for nothing" :) Barrie > > >  > Wayne, think of it this way. > > As with all physics 101 items, we are assuming weightless, frictionless, > low-cal lines and pulleys. > > There is some work to be done. That work is to raise (e.g.) a 100 lb > weight up a 50 foot mast. Regardless of how you do it, that is the work to > be done. Now let's put in the pulleys with three lines (3:1 purchase). > Regardless of this intermediate rig, there is a weight of 100lb pulling at > both the top and the bottom of the contraption. > > Work can be called a force applied through a distance. With the 3 line > rig, your puller will have to pull 3 times as far to get the work done. But > the total work is the same (a 100 lb weight up a 50 foot mast). Therefore > the puller will have to pull 1/3 as hard for 3 times as long. Your puller > has to pull in 150 feet of line to take the weight up the 50 foot mast. It > seems easier because the puller has to pull only 1/3 as hard, but for a > longer time. > > As far as the weight distribution goes, as I said above "Regardless of this > intermediate rig, there is a weight of 100lb pulling at both the top and the > bottom of the contraption." If there are three lines in between the top > and bottom, they share that 100lb load equally, or about 33 lbs apiece. > > The pulley rigs are meant to reduce the instantaneous force required, but > spread it over a longer time or distance. This why we old folks buy 2:1 and > 3:1 winches. Don't have to pull as hard, but we have to pull longer - which > overall seems easier. > > Cheers > Charlie >

Charlie - you're a genius - what a beautiful way to explain it. Just like Newton. No something for nothing - you don't get out what you don't put in, (and usually a lot less, as ours or anything's effort tends to wander off into the universe (2nd law)). All based on the concept of 'work' something we measure with gravity. What we struggle against to get out of bed and go to work each day. - Nick --- In Ca… [at] yahoogroups.com, "Husar, Charlie [USA]" <husar_charlie@...> wrote: > > Wayne, think of it this way.

Good explanation, clear concise, My Best, Mike From: "Husar, Charlie [USA]" <hu… [at] bah.com> To: "Ca… [at] yahoogroups.com" <Ca… [at] yahoogroups.com> Sent: Tue, August 31, 2010 8:06:38 PM Subject: [Cal_Boats] Work Factor for Pulleys (Wayne)  Wayne, think of it this way. As with all physics 101 items, we are assuming weightless, frictionless, low-cal lines and pulleys. There is some work to be done. That work is to raise (e.g.) a 100 lb weight up a 50 foot mast. Regardless of how you do it, that is the work to be done. Now let's put in the pulleys with three lines (3:1 purchase). Regardless of this intermediate rig, there is a weight of 100lb pulling at both the top and the bottom of the contraption. Work can be called a force applied through a distance. With the 3 line rig, your puller will have to pull 3 times as far to get the work done. But the total work is the same (a 100 lb weight up a 50 foot mast). Therefore the puller will have to pull 1/3 as hard for 3 times as long. Your puller has to pull in 150 feet of line to take the weight up the 50 foot mast. It seems easier because the puller has to pull only 1/3 as hard, but for a longer time. As far as the weight distribution goes, as I said above "Regardless of this intermediate rig, there is a weight of 100lb pulling at both the top and the bottom of the contraption." If there are three lines in between the top and bottom, they share that 100lb load equally, or about 33 lbs apiece. The pulley rigs are meant to reduce the instantaneous force required, but spread it over a longer time or distance. This why we old folks buy 2:1 and 3:1 winches. Don't have to pull as hard, but we have to pull longer - which overall seems easier. Cheers Charlie From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Wayne Gillikin Sent: Tuesday, August 31, 2010 9:32 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Hang on a minute. If there is a 100 lb weight at the end of a line passed through a block aloft and I pull on that line with enough force to lift the weight (100 lbs) then there is twice the original 100 lbs. Yes? No? Regards, Wayne From: John Boyce <je… [at] gmail.com> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 8:41:59 PM Subject: RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  If a 100 pound weight is lifted on a halyard the force on the halyard is 100 pounds If a block and tackle is attached to the hoist and the block and tackle is used to lift the load the force on the halyard is 100 pounds plus the weight of the block and tackle. If there is only one block there is no advantage to those doing the hoisting and the force on the single block is 200 pounds If there are four blocks and a becket giving a mechanical advantage of 3 to 1 those lifting will have to pull 33 pounds, the halyard still has 100 pounds of force, the connection between the weight and the first block has a force of 100 pounds, the last block (assuming four independent blocks has 66 pounds of force and .... Just drop the mast the sheave is probably frozen and the shaft goes through both the main and the genoa sheaves and the genoa halyard on a roller furler is probably so chafed that it will fail and the 100 pound weight will make a big mess on the deck. John B From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of John Courter Sent: Monday, August 30, 2010 5:47 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. It actually increases load on the halyard. Taking the simplest case, a block hoisted up on the halyard gets you no advantage, but if you're lifting 100 lbs, then there is 100 lbs of load on each part adding to 200 lbs of load on the halyard supporting the block. John From: Mark Alan Stahnke (MAS Consulting) <ma… [at] cox.net> To: Ca… [at] yahoogroups.com Sent: Mon, August 30, 2010 11:47:05 AM Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast.  When we go up the mast we use a halyard to hoist up a 3:1 tackle then run that thru a winch...Its much faster and reduces the load on the halyard and sheave. Mark >From: John Courter >To: Ca… [at] yahoogroups.com >Sent: Monday, August 30, 2010 9:36 AM >Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. > > >Why can't you unroll the jib, lower it then use the jib halyard? You can then >use the spin halyard as the safety backup. > >John > > > > From: Chris Campbell <cl… [at] charterinternet.com> >To: Ca… [at] yahoogroups.com >Sent: Mon, August 30, 2010 9:15:46 AM >Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. > > >wirelessmonster wrote: > >> >>I don't know about the safety aspect compared to the main halyard, but when my >>main was fouled I went up the mast with the spinnaker halyard since we have >>roller furling on the jib. It worked, but who knows how safe it was. >> My own preference for going aloft in a bosun's chair is to have two halyards, so there's some backup in case the first one fails (a real possibility in an older, neglected boat). You could try to examine the masthead with binoculars, or perhaps go aloft in a neighboring boat with good halyards just to look over at yours. Chris Campbell > > >__________ Information from ESET NOD32 Antivirus, version of virus signature >database 5409 (20100830) __________ > >The message was checked by ESET NOD32 Antivirus. > >http://www.eset.com > __________ Information from ESET NOD32 Antivirus, version of virus signature database 5409 (20100830) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

Husar, Charlie [USA] wrote: > > >  > > Wayne, think of it this way. > > As with all physics 101 items, we are assuming weightless, > frictionless, low-cal lines and pulleys. > > There is some work to be done. That work is to raise (e.g.) a 100 lb > weight up a 50 foot mast. Regardless of how you do it, that is the > work to be done. Now let's put in the pulleys with three lines (3:1 > purchase). Regardless of this intermediate rig, there is a weight of > 100lb pulling at both the top and the bottom of the contraption. > > Work can be called a force applied through a distance. With the 3 > line rig, your puller will have to pull 3 times as far to get the work > done. But the total work is the same (a 100 lb weight up a 50 foot > mast). Therefore the puller will have to pull 1/3 as hard for 3 times > as long. Your puller has to pull in 150 feet of line to take the > weight up the 50 foot mast. It seems easier because the puller has > to pull only 1/3 as hard, but for a longer time. > > As far as the weight distribution goes, as I said above "Regardless of > this intermediate rig, there is a weight of 100lb pulling at both the > top and the bottom of the contraption." If there are three lines in > between the top and bottom, they share that 100lb load equally, or > about 33 lbs apiece. Hey, Charlie, are you a teacher? If not, you ought to be. You can make a complex concept comprehensible, in clear prose. Good work. It's a gift and you've got it. Our local marine historical group has a captain who's a gifted woodworker, both in his trade as a timber framer and in his hobby as a boatbuilder and sailor. When some newbie is about to do something really stupid, he'll wander over and say, "here's how I like to do it." No shouting about stupidity and blunders, just a demonstration of the right way. It's an effective way of teaching. Chris Campbell >

When looking for a ascender hardware, I realized the mountaineering gear is made for a different kind of line (rope) and the teeth in the ascenders may be too harsh for typical sailing gear. I ended up with these.. http://www.atninc.com/topclimber_en.php I use a 6' harness to tie to the mast, then I can only fall as far as the last spreader (G) I will agree with Timm, working from a bosuns chair is not very comfortable or efficient. Our local boat yard has a "cherry picker" boom truck and can get most jobs completed without the risk of climbing, and much less expensive. YMMV John From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of chris123 Sent: Tuesday, August 31, 2010 5:09 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. Given this situation and others, is one of the main reasons I want to install these (see below) on the mast ever 18". Mast steps (several sources and models available) http://www.thechandleryonline.com//product.asp?pf_id=054_A81000 <http://www.thechandleryonline.com/product.asp?pf_id=054_A81000&dept_id=1717 > &dept_id=1717 With a good harness and safety rig, it is possible to do it yourself, both up and down using whatever lines are available on your vessel in any given situation. Given that fact that you are not indestructible, best done at dockside but can be done while on an anchor if you really have too. harnesses http://www.rei.com/search?query=harness <http://www.rei.com/search?query=harness&button.x=0&button.y=0> &button.x=0&button.y=0 brakes (ascenders & descenders) http://www.rei.com/category/4500694 Combine that kit with a simple tool bag and your tools each on there own line tied to the bag your should be in good shape. Best /ch

What is nice about collapsable climbers on the mast is that you are much safer and it can be done at any time. You use the harness only as a safety device and the ascender/descender as a break on the any line in case you fall. You pull yourself up on the steps not the lines. The primary safety device is a simple rope that you swing around the mast and attach to the harness at both ends. So as you open the next step, you snap the line above it, just like the hydro guys used to do in days gone by. For me it works well and has two levels of safety: the rope attached to the harness and wrapped around the mast, and the ascender/descender which serves as a break in case you fall off the steps and the rope fails. Doubled lines are a good thing. You probably will do severe damage to the family jewels if you fall, so it more a balancing act that you need to be cognisant off. ie: lean back agains the primary rope around the mast as you go up. Again just like the hydro guys or if you are rapelling down a cliff the old way with lines in your hands. Its tricky but once you get used to it, its actually comfortable. Finally Im getting older, so climbing on fixed steps is less fatiguing then the ATN for me at least. YMMV. All the best. /ch On Fri, Sep 3, 2010 at 7:11 PM, john raxter <jr… [at] triad.rr.com> wrote: > > > When looking for a ascender hardware, I realized the mountaineering gear > is made for a different kind of line (rope) and the teeth in the ascenders > may be too harsh for typical sailing gear. > > > > I ended up with these…. > > > > http://www.atninc.com/topclimber_en.php > > > > I use a 6’ harness to tie to the mast, then I can only fall as far as the > last spreader (G) > > > > I will agree with Timm, working from a bosuns chair is not very > comfortable or efficient. > > > > Our local boat yard has a “cherry picker” boom truck and can get most jobs > completed without the risk of climbing, and much less expensive. > > > > YMMV > > John > > > > > > *From:* Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] *On > Behalf Of *chris123 > *Sent:* Tuesday, August 31, 2010 5:09 PM > > *To:* Ca… [at] yahoogroups.com > *Subject:* Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of > mast. > > > > > > Given this situation and others, is one of the main reasons I want to > install these (see below) on the mast ever 18". > > Mast steps (several sources and models available) > > http://www.thechandleryonline.com//product.asp?pf_id=054_A81000&dept_id=1717<http://www.thechandleryonline.com/product.asp?pf_id=054_A81000&dept_id=1717> > > With a good harness and safety rig, it is possible to do it yourself, both > up and down using whatever lines are available on your vessel in any given > situation. Given that fact that you are not indestructible, best done at > dockside but can be done while on an anchor if you really have too. > > harnesses > http://www.rei.com/search?query=harness&button.x=0&button.y=0 > > brakes (ascenders & descenders) > http://www.rei.com/category/4500694 > > Combine that kit with a simple tool bag and your tools each on there own > line tied to the bag your should be in good shape. > > Best > > /ch > > > -- /ch

I use a ATN topclimber on a line attached to the jib halyard at the top and to the jib tack pulled tight. I then climb up at an angle along the forestay with a prussic knot on the forestay attached to a safety harness. It is much easier to move the prussic knot along the forestay than along a line. Just make sure the line you are climbing is very tight. It is easier to climb using the topclimber if it is at this kind of an angle. They recommend this at ATN. On the other topic of how much force is on the halyard if you are using a block and tackle to climb. It is the weight of the load times 1 plus the inverse of the purchase. So, if you have a 4:1 purchase and 100 pound load it is 100 pounds of the load plus the 25 pounds the guy doing the pulling is doing. Now, if you pull from the chair, it is only 100 pounds and not only that but what was a 4:1 setup will now be a 5:1. For example, a single block pulling someone up the mast will be 1:1 (no advantage) if pulled from the ground but will be 2:1 if the guy in the chair is pulling himself up. This confuses most people so if you think it is wrong just consider how much line you will pull in if you are on the chair compared to how far you move. If you have a 50 ft mast and a single block, you have 100 feet of line. The guy on the ground pulls 50 feet of line to hoist the load but someone on the chair pulls in the entire 100 feet. Cheers, Allen

One thing to consider is a simple equation F = M x A or force equals mass times acceleration. So, if the thing isn't accelerating, then the sum of all forces on it is zero. It can be moving and have net zero force if it is not accelerating. So basically, all these diagrams have the sum of all forces equal to zero. Another way to say it is that the forces up equal the forces down. The other trick to solving these kind of problems is that the force on the rope is always the same as it goes over the various blocks. If lines go off at angles, then it gets more complicated but the same thing holds that the sum of all the forces is zero. The reality is that the force on the line is not the same because there is friction in the blocks so if you get too many blocks in your system it won't work well, but that is always ignored in these discussions. Allen On Tue, Aug 31, 2010 at 9:30 AM, Wayne Gillikin <wa… [at] yahoo.com>wrote: > > Thanks, Tim. Very illuminating. > > Regards, > Wayne > ------------------------------ > *From:* "ti… [at] ch2m.com" <ti… [at] ch2m.com> > *To:* Ca… [at] yahoogroups.com > *Sent:* Tue, August 31, 2010 12:16:26 PM > *Subject:* RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of > mast. (Harken) > > > > For the Harken table you must think relative to the force on the strap > holding the block to the deck or whatever the attachment point is. > > > > Picture the block attached to a spring scale that measures how much pull > there is on the attachment. > > > > [L] = load > > O = block > > --- =line > > (^) = scale > > > > If [L]----------O---------à100lbs > > * (^) 0lbs (Harken point of reference)* > > > > > > Load/line straight with the block, then the scale would read zero “the line > does not touch the block” so at zero angle the force on the block is - > nothing. > > > ------------------------------ > > > > If as below the F/2 = the sheet load is [SL]… so > > > > [SL] times two = F - or as Harken has said *F= 200% (2x) the [SL]* > > > > [image: > http://upload.wikimedia.org/wikipedia/commons/thumb/c/c7/Pulley0.svg/63px-Pulley0.svg.png]<http://en.wikipedia.org/wiki/File:Pulley0.svg> > > * (^) = 2x line load or 200% line load = full force/weight. * > > F=100lbs > > F/2=50lbs > > 2x50=100lbs > > > > > > > > > > > > *From:* Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] *On > Behalf Of *Wayne Gillikin > *Sent:* Tuesday, August 31, 2010 8:56 AM > *To:* Ca… [at] yahoogroups.com > *Subject:* Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of > mast. (Harken) > > > > Thanks, Tim. > > > > Please bear with me for a (hopefully) final question. Are you saying that > the load on a line without any deflection is simply the load and when you > deflect the line 180 degrees around a block the load on the line on each > side of the block is halved so the load on the block is still only the > original load on the undeflected line? So the load factor is increasing > with deflection but the load is being shared by the lines and is decreasing? > > > > I thought the Harken example was saying that if you calculated the force on > a sail and you took the sheet through a block that turned it 180 degrees you > had twice the force on the block. You're saying I was completely misreading > the Harken chart. > > > > Back to the drawing board! > > > > Regards, > > Wayne > > > ------------------------------ > > *From:* "ti… [at] ch2m.com" <ti… [at] ch2m.com> > *To:* Ca… [at] yahoogroups.com > *Sent:* Tue, August 31, 2010 11:11:23 AM > *Subject:* RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of > mast. (Harken) > > > > Simple read the part in the Harken Manual: > > > > “load equal to twice the load on the sheet…” > > > > It is the first diagram “backwards” the sheet load is L/2… so at 90 degree > loading, the load to hold the block is twice the sheet load. [image: > http://upload.wikimedia.org/wikipedia/commons/thumb/c/c7/Pulley0.svg/63px-Pulley0.svg.png]<http://en.wikipedia.org/wiki/File:Pulley0.svg> > > > > > > > > *From:* Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] *On > Behalf Of *Wayne Gillikin > *Sent:* Tuesday, August 31, 2010 8:07 AM > *To:* Ca… [at] yahoogroups.com > *Subject:* Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of > mast. (Harken) > > > > > > In Tim's first diagram it seems that the load on the block is only F (the > weight suspended from it) and the load on each line is F/2. But how does > that square with this info from the Harken site ( > http://www.harken.com/charts/blockloadvangle.php). Isn't this saying that > the load on the block is twice the force/weight? > > > > Does the issue of equilibrium have anything to do with it? So, if the > weight is simply hanging there it distributes its weight evenly between the > two lines and the block only experiences the force of the weight. However, > it if I need to raise the weight then I have to apply additional force? > Does that make any sense? > > > > I am not even close to an engineer so please keep your explanation simple. > I genuinely don't understand this and find it extremely puzzling. > > > > *BLOCK LOADING VS ANGLE OF DEFLECTION* > > > > Load on a block is a combination of the load on the line passing through > the block, plus a block-loading factor, which is determined by the angle by > which the block turns the sheet . For example, a footblock that turns a > sheet 180° will see a load equal to twice the load on the sheet. A deck > organizer, which turns a halyard only 30°, will see just 52% of the load on > the halyard. > > > ------------------------------ > > Angle of deflection > > Load factor > > * * > > Angle of Deflection > > Load factor > ------------------------------ > ------------------------------ > > 30° > > 52% > > 120° > > 173% > ------------------------------ > ------------------------------ > > 45° > > 76% > > 135° > > 185% > ------------------------------ > ------------------------------ > > 60° > > 100% > > 150° > > 193% > ------------------------------ > ------------------------------ > > 75° > > 122% > > 160° > > 197% > ------------------------------ > ------------------------------ > > 90° > > 141% > > 180° > > 200% > ------------------------------ > ------------------------------ > > 105° > > 159% > > > > > ------------------------------ > > *Copyright© 2010 Harken, Inc. All rights reserved > If you would like to link to or reprint this article please contact Brownie > Lewis <http://harken.com/email/HarkenAdvertising.aspx>* > ------------------------------ > > *From:* "ti… [at] ch2m.com" <ti… [at] ch2m.com> > *To:* Ca… [at] yahoogroups.com > *Sent:* Tue, August 31, 2010 10:26:37 AM > *Subject:* RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of > mast. Wikipedia > > > How it works > > [image: > http://upload.wikimedia.org/wikipedia/commons/thumb/c/c7/Pulley0.svg/63px-Pulley0.svg.png]<http://en.wikipedia.org/wiki/File:Pulley0.svg> > > Diagram 1 - A basic equation for a pulley: In equilibrium, the force *F*on the pulley axle is equal and opposite to the sum of the > tensions <http://en.wikipedia.org/wiki/Tension_(mechanics)> in each line > leaving the pulley, and these tensions are equal. > > [image: > http://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/Pulley1.svg/80px-Pulley1.svg.png]<http://en.wikipedia.org/wiki/File:Pulley1.svg> > > Diagram 2 - A simple pulley system - a single movable pulley lifting weight > *W*. The tension in each line is *W/2*, yielding an advantage of 2. > > [image: > http://upload.wikimedia.org/wikipedia/commons/thumb/8/86/Pulley1a.svg/80px-Pulley1a.svg.png]<http://en.wikipedia.org/wiki/File:Pulley1a.svg> > > Diagram 2a - Another simple pulley system similar to diagram 2, but in > which the lifting force is redirected downward. > > [image: > http://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/Polispasto2B.jpg/68px-Polispasto2B.jpg]<http://en.wikipedia.org/wiki/File:Polispasto2B.jpg> > > > > > > A practical compound pulley corresponding to diagram 2a > > > > [image: > http://upload.wikimedia.org/wikipedia/commons/thumb/6/6c/Pulley2.svg/80px-Pulley2.svg.png]<http://en.wikipedia.org/wiki/File:Pulley2.svg> > > Diagram 3 - A simple compound pulley system: a movable pulley and a fixed > pulley lifting weight *W*. The tension in each line is *W/3*, yielding an > advantage of 3. > > [image: > http://upload.wikimedia.org/wikipedia/commons/thumb/d/d4/Pulley2a.svg/100px-Pulley2a.svg.png]<http://en.wikipedia.org/wiki/File:Pulley2a.svg> > > Diagram 3a - A simple compound pulley system: a movable pulley and a fixed > pulley lifting weight *W*, with an additional pulley redirecting the > lifting force downward. The tension in each line is *W/3*, yielding an > advantage of 3. > > [image: > http://upload.wikimedia.org/wikipedia/commons/thumb/1/17/Pulley3a.svg/107px-Pulley3a.svg.png]<http://en.wikipedia.org/wiki/File:Pulley3a.svg> > > Diagram 4a - A more complicated compound pulley system. The tension in each > line is *W/4*, yielding an advantage of 4. An additional pulley > redirecting the lifting force has been added. > > [image: > http://upload.wikimedia.org/wikipedia/commons/thumb/2/2a/Polispasto4.jpg/75px-Polispasto4.jpg]<http://en.wikipedia.org/wiki/File:Polispasto4.jpg> > > Figure 4b - A practical block and tackle pulley system corresponding to > diagram 4a. Note that the axles of the fixed and movable pulleys have been > combined. > > > > *From:* Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] *On > Behalf Of *Wayne Gillikin > *Sent:* Tuesday, August 31, 2010 6:32 AM > *To:* Ca… [at] yahoogroups.com > *Subject:* Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of > mast. > > > > > > Hang on a minute. If there is a 100 lb weight at the end of a line passed > through a block aloft and I pull on that line with enough force to lift the > weight (100 lbs) then there is twice the original 100 lbs. Yes? No? > > > > Regards, > > Wayne > > > ------------------------------ > > *From:* John Boyce <je… [at] gmail.com> > *To:* Ca… [at] yahoogroups.com > *Sent:* Mon, August 30, 2010 8:41:59 PM > *Subject:* RE: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of > mast. > > > >  > > If a 100 pound weight is lifted on a halyard the force on the halyard is > 100 pounds > > > > If a block and tackle is attached to the hoist and the block and tackle is > used to lift the load the force on the halyard is 100 pounds plus the weight > of the block and tackle. > > > > If there is only one block there is no advantage to those doing the > hoisting and the force on the single block is 200 pounds > > > > If there are four blocks and a becket giving a mechanical advantage of 3 to > 1 those lifting will have to pull 33 pounds, the halyard still has 100 > pounds of force, the connection between the weight and the first block has a > force of 100 pounds, the last block (assuming four independent blocks has 66 > pounds of force and .... > > > > Just drop the mast the sheave is probably frozen and the shaft goes through > both the main and the genoa sheaves and the genoa halyard on a roller furler > is probably so chafed that it will fail and the 100 pound weight will make a > big mess on the deck. > > > > John B > > > > > ------------------------------ > > *From:* Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] *On > Behalf Of *John Courter > *Sent:* Monday, August 30, 2010 5:47 PM > *To:* Ca… [at] yahoogroups.com > *Subject:* Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of > mast. > > > > It actually increases load on the halyard. Taking the simplest case, a > block hoisted up on the halyard gets you no advantage, but if you're lifting > 100 lbs, then there is 100 lbs of load on each part adding to 200 lbs of > load on the halyard supporting the block. > > > > John > > > ------------------------------ > > *From:* Mark Alan Stahnke (MAS Consulting) <ma… [at] cox.net> > *To:* Ca… [at] yahoogroups.com > *Sent:* Mon, August 30, 2010 11:47:05 AM > *Subject:* Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of > mast. > > > >  > > When we go up the mast we use a halyard to hoist up a 3:1 tackle then run > that thru a winch...Its much faster and reduces the load on the halyard and > sheave. > > Mark > > > > ----- Original Message ----- > > *From:* John Courter <ca… [at] yahoo.com> > > *To:* Ca… [at] yahoogroups.com > > *Sent:* Monday, August 30, 2010 9:36 AM > > *Subject:* Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of > mast. > > > > > > Why can't you unroll the jib, lower it then use the jib halyard? You can > then use the spin halyard as the safety backup. > > > > John > > > ------------------------------ > > *From:* Chris Campbell <cl… [at] charterinternet.com> > *To:* Ca… [at] yahoogroups.com > *Sent:* Mon, August 30, 2010 9:15:46 AM > *Subject:* Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of > mast. > > > > wirelessmonster wrote: > > > > > I don't know about the safety aspect compared to the main halyard, but when > my main was fouled I went up the mast with the spinnaker halyard since we > have roller furling on the jib. It worked, but who knows how safe it was. > > > My own preference for going aloft in a bosun's chair is to have two > halyards, so there's some backup in case the first one fails (a real > possibility in an older, neglected boat). > > You could try to examine the masthead with binoculars, or perhaps go aloft > in a neighboring boat with good halyards just to look over at yours. > > Chris Campbell > > > > > > __________ Information from ESET NOD32 Antivirus, version of virus > signature database 5409 (20100830) __________ > > The message was checked by ESET NOD32 Antivirus. > > http://www.eset.com > > > > __________ Information from ESET NOD32 Antivirus, version of virus > signature database 5409 (20100830) __________ > > The message was checked by ESET NOD32 Antivirus. > > http://www.eset.com > > > > > > > > > >

> > > if I need to raise the weight then I have to apply additional force? > Just to expand on my other reply, the same force that will hold something in equilibrium can raise it. You need a small additional force to get it moving and to overcome friction but those are ignored in the analysis you are looking at. Allen

Hi, All. Allen is right on in that the force on the halyard when raising the weight is greater than the example of loads I previously discussed. Additionally... ...well, here goes... My example of loads on the halyard and block rig was a static example of the distribution of the load and did not include friction - which is velocity dependent - and other very real factors. In fact, I am moving the weight up the mast, meaning I am adding force beyond gravity to move the weight. However, the actual force on the line is dependent on how fast the puller is pulling. (added force being mass times acceleration as Allen states). The value of the force on the line varies according to pull speed; it is not necessarily (but can be) the 25 added lbs the puller is pulling in the 4:1 rig as Allen suggested in previous note. On one end of the load scale, the pull speed is verrryyy slow. After a long time, the weight will be up the mast. The force on the halyard is almost no bigger than the static example of 100lb. On the other hand, if the pull speed is great, the load on the halyard can be huge. If I really jerk the line, it could be thousands of pounds. After all, I am forcing the weight on the line to accelerate and move very quickly. Even as the speeds vary, the total work is the same. It is just a matter of small force for long time or a larger force for less time. Still 100lb up a fifty foot mast. An example for added forces would be that I want to break a piece of thread. If I pull gradually, it may not break since I am not pulling hard enough to exceed the thread strength. Now if I jerk the thread quickly, I am applying a bunch more force for a brief period and the thread breaks. You will note that if you do not trust a line, you pull slowly and steadily to minimize its chance of breaking. At a specific speed of pull, the added force on the halyard is indeed 25 lbs. We could calculate that, but I will leave it as an exercise to the reader. Don't forget that the force of gravity at the Earth's surface is usually taken as 9.8 meters/sec squared. It will vary with altitude, moon position, and earth density below you - definitely lower order effects. (In the limit of high speed, relativistic effects take over and the calculation becomes more complex.) I'm not sure that the max message size on this list could handle the size of the equation that includes relativity, g force variation, line stretch, friction (static and moving), use of 3-in-1 oil, and all that stuff. :- ] Did you know that the GPS you use is a demonstration of Einstein's theory of relativity? To achieve the required GPS accuracy, the speed of the satellites requires that the clocks be compensated because time slows down as speed increases. The satellites are doing about 18,000 mph. OK, OK. Much more than enough from me. Get a jockey to run up the mast, a halyard and a safety line, and a winch grinder with a bit of oomph. I guess the original problem was that the main block is stuck or the halyard is somehow pinched up there. I vote the latter, since the line should slide over a stuck block with some effort. Good thing about being 200 lb. I am rarely asked to go up the mast (but often asked to grind). Cheers Charlie From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Allen Edwards Sent: Monday, September 06, 2010 1:04 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. (Harken) if I need to raise the weight then I have to apply additional force? Just to expand on my other reply, the same force that will hold something in equilibrium can raise it. You need a small additional force to get it moving and to overcome friction but those are ignored in the analysis you are looking at. Allen

> Did you know that the GPS you use is a demonstration of Einstein's theory > of relativity? To achieve the required GPS accuracy, the speed of the > satellites requires that the clocks be compensated because time slows down > as speed increases. The satellites are doing about 18,000 mph. > Funny you should say that. I worked for one of the the guys who invented GPS for a few years and he tried to explain it to me once. I thought I understood relativity but when he said the clock would lose the same time per orbit regardless of its speed... something about the angular acceleration, my response was... huh? I don't understand it so don't ask. Allen

--- In Ca… [at] yahoogroups.com, "Husar, Charlie [USA]" <husar_charlie@...> wrote: > Good thing about being 200 lb. I am rarely asked to go up the mast (but often asked to grind). I have relied on the same theory but it does not always work. Once on our schooner a halyard had gone up the topmast or jammed there or something. The captain called for volunteers. There was a deafening silence. The prospect of going all the way up was slightly frightening, so I spoke up. "I'll go if you can haul me." The captain, whose good judgment is well known, said "I can haul you up." Remember, this schooner has no winches, so he sweated me up to the top with brute strength. I was at about 200 lbs then. Chris Campbell

Allen, since the orbital speed gets lower as the orbit gets larger, one orbit means more time at less speed. Is it possible that the time of orbit and the speed (note I am saying scalar speed instead of vector velocity) of the object offset each other? That is, is it possible that the speed drops out of the computation and we can just count orbits to determine relativistic effects? Haven't screwed around with my math in a while. Maybe if things get real dull... I am desperately seeking a sailing connection here. Cheers, Anyway Charlie From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Allen Edwards Sent: Monday, September 06, 2010 10:09 AM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. (Harken) Did you know that the GPS you use is a demonstration of Einstein's theory of relativity? To achieve the required GPS accuracy, the speed of the satellites requires that the clocks be compensated because time slows down as speed increases. The satellites are doing about 18,000 mph. Funny you should say that. I worked for one of the the guys who invented GPS for a few years and he tried to explain it to me once. I thought I understood relativity but when he said the clock would lose the same time per orbit regardless of its speed... something about the angular acceleration, my response was... huh? I don't understand it so don't ask. Allen

That may be it but I seem to remember something about the orbit being a circle implied constant acceleration and that had something to do with it. I understand the idea that a clock made of two mirrors with a light pulse going between them at the speed of light implies that time is different for a person on a train with the light clock then for an observer on the ground watching the train and the clock go by. That is pretty simple as the stationary observer sees the path between the mirrors as longer and if light speed is constant, time is longer for him. Or is it shorter??? My boat isn't that fast so I don't worry about it although I am happy that my old boss worried about it when they designed the GPS system. I just ordered a Foretrex 301 so that I can have my GPS on my wrist and see it when I am on the rail. I can put VMG, TURN, Time to Next, and SPEED on it at one time. Can't wait until the next race. TURN is a great function that I just discovered. It tells you what direction to turn the boat to get to the mark and how much. The other GPS function that I just learned is to set a route between the committee boat and the pin. Then set the GPS to OFF COURSE and it will tell you how far you are away from the starting line. Way cool. Allen On Tue, Sep 7, 2010 at 8:08 AM, Husar, Charlie [USA] <hu… [at] bah.com>wrote: > > > Allen, since the orbital speed gets lower as the orbit gets larger, one > orbit means more time at less speed. Is it possible that the time of orbit > and the speed (note I am saying scalar speed instead of vector velocity) of > the object offset each other? That is, is it possible that the speed drops > out of the computation and we can just count orbits to determine > relativistic effects? Haven't screwed around with my math in a > while. Maybe if things get real dull... > > I am desperately seeking a sailing connection here. > > Cheers, Anyway > Charlie > > ------------------------------ > *From:* Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] *On > Behalf Of *Allen Edwards > *Sent:* Monday, September 06, 2010 10:09 AM > *To:* Ca… [at] yahoogroups.com > *Subject:* Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of > mast. (Harken) > > > Did you know that the GPS you use is a demonstration of Einstein's >> theory of relativity? To achieve the required GPS accuracy, the speed of the >> satellites requires that the clocks be compensated because time slows down >> as speed increases. The satellites are doing about 18,000 mph. >> > > Funny you should say that. I worked for one of the the guys who invented > GPS for a few years and he tried to explain it to me once. I thought I > understood relativity but when he said the clock would lose the same time > per orbit regardless of its speed... something about the angular > acceleration, my response was... huh? I don't understand it so don't ask. > > Allen > > >