Re: Another Fatal Accident

Rudders! Why are our yacht designers creating rudders that fall off? In 1998 I was in the Pacific cup race to Hawaii from San Francisco. We were in a fleet of roughly 75 boats and I remember being amazed that about 4 or5 (the exact number is lost to my poor memory) of our fleet lost it rudder in the 10-20 day sail to Hawaii! What if there was a endurance road race and 3-5% of the cars lost their steering due to mechanical failure? What would be the reaction? I am an machine design engineer and this particular failure is mostly preventable by good design.

This makes me think of a story my Uncle told me. He was a rocket scientist. Fresh out of CalTech at Douglas Aircraft he was talking with someone who was explaining a problem they had. The control fins (rudders) on the Nike missiles were falling off in flight. My Uncle said, that is because you have the pivot point at the end of the fin. It needs to be aft a little bit from the forward edge or you will get a vibration that will cause the fin (rudder) to fall off. They changed it and no more failures. That was a good way to start a new career and he did very well ending up being chief of structures for the missile division. I would be curious if the rudders that are failing have the shaft right at the forward edge of the rudder. You may notice that the Cal-40 does not have that problem as the shaft is aft of the forward edge. Maybe all boats do. Allen On Tue, Mar 12, 2013 at 8:22 PM, Greg Branch <th… [at] hotmail.com> wrote: > ** > > > Rudders! **** > > ** ** > > Why are our yacht designers creating rudders that fall off? **** > > ** ** > > In 1998 I was in the Pacific cup race to Hawaii from San Francisco. We > were in a fleet of roughly 75 boats and I remember being amazed that about > 4 or5 (the exact number is lost to my poor memory) of our fleet lost it > rudder in the 10-20 day sail to Hawaii! What if there was a endurance > road race and 3-5% of the cars lost their steering due to mechanical > failure? What would be the reaction? I am an machine design engineer > and this particular failure is mostly preventable by good design.**** > > >

What are the dangers, if any with the cal rudder....anybody ever had an, oh crap moment? I know that it would be very difficult to gain access to the rudder through the lazarette late at night upside down to patch something. I think about hitting a deadhead and ripping the post since its so vulnerable how it is exposed off of the hull. --- In Ca… [at] yahoogroups.com, Allen Edwards <allen.p.edwards@...> wrote: > > This makes me think of a story my Uncle told me. He was a rocket > scientist. Fresh out of CalTech at Douglas Aircraft he was talking with > someone who was explaining a problem they had. The control fins (rudders) > on the Nike missiles were falling off in flight. My Uncle said, that is > because you have the pivot point at the end of the fin. It needs to be aft > a little bit from the forward edge or you will get a vibration that will > cause the fin (rudder) to fall off. They changed it and no more failures. > That was a good way to start a new career and he did very well ending up > being chief of structures for the missile division. > > I would be curious if the rudders that are failing have the shaft right at > the forward edge of the rudder. You may notice that the Cal-40 does not > have that problem as the shaft is aft of the forward edge. Maybe all boats > do. > > Allen > > On Tue, Mar 12, 2013 at 8:22 PM, Greg Branch <thudbranch@...> wrote: > > > ** > > > > > > Rudders! **** > > > > ** ** > > > > Why are our yacht designers creating rudders that fall off? **** > > > > ** ** > > > > In 1998 I was in the Pacific cup race to Hawaii from San Francisco. We > > were in a fleet of roughly 75 boats and I remember being amazed that about > > 4 or5 (the exact number is lost to my poor memory) of our fleet lost it > > rudder in the 10-20 day sail to Hawaii! What if there was a endurance > > road race and 3-5% of the cars lost their steering due to mechanical > > failure? What would be the reaction? I am an machine design engineer > > and this particular failure is mostly preventable by good design.**** > > > > > > >

Greg, I was thinking, if these designers want to design so close to the edge of break-ability, especially on an off shore boat, they should, at least, provide for an emergency back up rudder system. You have to see the brochure on the Columbia Carbon 32 to see how long, thin and skinny the rear foil is as well as the keel foil and bulb. Another idea would be to use twin rudders, like the Transat 21's and others. Jerry From: Greg Branch <th… [at] hotmail.com> To: Ca… [at] yahoogroups.com Sent: Tuesday, March 12, 2013 8:22 PM Subject: [Cal_Boats] Re: Another Fatal Accident Rudders! Why are our yacht designers creating rudders that fall off? In 1998 I was in the Pacific cup race to Hawaii from San Francisco. We were in a fleet of roughly 75 boats and I remember being amazed that about 4 or5 (the exact number is lost to my poor memory) of our fleet lost it rudder in the 10-20 day sail to Hawaii! What if there was a endurance road race and 3-5% of the cars lost their steering due to mechanical failure? What would be the reaction? I am an machine design engineer and this particular failure is mostly preventable by good design.

Offshore racing regs do require an emer tiller and rudder. Unfortunately, most emer rudders are a floorboard attached to a spin pole or some other flimmzy method that passes inspection. Nick From: "Gerald Sobel" <so… [at] yahoo.com> To: "Cal Boats" <Ca… [at] yahoogroups.com> Sent: Wednesday, March 13, 2013 1:02:34 AM Subject: Re: [Cal_Boats] Re: Another Fatal Accident Greg, I was thinking, if these designers want to design so close to the edge of break-ability, especially on an off shore boat, they should, at least, provide for an emergency back up rudder system. You have to see the brochure on the Columbia Carbon 32 to see how long, thin and skinny the rear foil is as well as the keel foil and bulb. Another idea would be to use twin rudders, like the Transat 21's and others. Jerry From: Greg Branch <th… [at] hotmail.com> To: Ca… [at] yahoogroups.com Sent: Tuesday, March 12, 2013 8:22 PM Subject: [Cal_Boats] Re: Another Fatal Accident Rudders! Why are our yacht designers creating rudders that fall off? In 1998 I was in the Pacific cup race to Hawaii from San Francisco. We were in a fleet of roughly 75 boats and I remember being amazed that about 4 or5 (the exact number is lost to my poor memory) of our fleet lost it rudder in the 10-20 day sail to Hawaii! What if there was a endurance road race and 3-5% of the cars lost their steering due to mechanical failure? What would be the reaction? I am an machine design engineer and this particular failure is mostly preventable by good design.

James polled the list: "What are the dangers, if any with the cal rudder....anybody ever had an, oh crap moment?" I've never had the pleasure of suddenly losing a rudder (at least not on anything larger than about 18 feet), but this raises an important point. I believe that there are two tasks that every sailor should practice at least once a year, in addition to the obvious MOB drills. 1. Practice heaving to. It's becoming a lost art, and is such a wonderful, practical maneuver that can come in useful in many cheek-clenching situations. 2. Practice steering without the rudder. By adjusting your sails, you can control where the boat goes - more or less - under most points of sail. In addition to being a handy skill to have, it will also teach you a lot about trimming your boat so that you can get rid of weather or lee helm when you encounter it. (If you're fortunate enough to have a centerboard, as we do now, don't forget that it is an important arrow in your quiver for this task.) Alfred Poor 1973 Tartan 34C #288 "Jambalaya"

There is an awesome '90's vintage interview with Bill Lapworth, somewhere in the groups document section. He states how his boats increased in performance by building them light and sea-worthy, and that he basically saw many new boats as un-seaworthy and not truly capable of sailing in the natural element's that you might encounter on a given day. A great read. Look it up. George Macon To: Ca… [at] yahoogroups.com From: ng… [at] comcast.net Date: Wed, 13 Mar 2013 12:49:19 +0000 Subject: Re: [Cal_Boats] Re: Another Fatal Accident Offshore racing regs do require an emer tiller and rudder. Unfortunately, most emer rudders are a floorboard attached to a spin pole or some other flimmzy method that passes inspection. Nick From: "Gerald Sobel" <so… [at] yahoo.com> To: "Cal Boats" <Ca… [at] yahoogroups.com> Sent: Wednesday, March 13, 2013 1:02:34 AM Subject: Re: [Cal_Boats] Re: Another Fatal Accident Greg, I was thinking, if these designers want to design so close to the edge of break-ability, especially on an off shore boat, they should, at least, provide for an emergency back up rudder system. You have to see the brochure on the Columbia Carbon 32 to see how long, thin and skinny the rear foil is as well as the keel foil and bulb. Another idea would be to use twin rudders, like the Transat 21's and others. Jerry From: Greg Branch <th… [at] hotmail.com> To: Ca… [at] yahoogroups.com Sent: Tuesday, March 12, 2013 8:22 PM Subject: [Cal_Boats] Re: Another Fatal Accident Rudders! Why are our yacht designers creating rudders that fall off? In 1998 I was in the Pacific cup race to Hawaii from San Francisco. We were in a fleet of roughly 75 boats and I remember being amazed that about 4 or5 (the exact number is lost to my poor memory) of our fleet lost it rudder in the 10-20 day sail to Hawaii! What if there was a endurance road race and 3-5% of the cars lost their steering due to mechanical failure? What would be the reaction? I am an machine design engineer and this particular failure is mostly preventable by good design.