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Build Own It Unfortunately the new Stomp 38 lost its rudder before the Sydney-Southport race, and here is the report from the boat's owner, Nick De Laine. Below that is designer Steve Thompson's response. About 10 min before the race started we were over at Nielson park hiding from the 30 plus knots. We then powered out of there under motor and main when I felt a sudden bang through the wheel. One of the crew went down to check the steering but it was all OK. A couple minutes later we went to do a granny tack to position ourselves for the start sequence but we couldn’t complete the tack so we bared away and tried again. I thought it was operator error the steering didn’t feel very good at this time; due to not having a jib up at this stage. The race started, we had the no.4 and 1 reef in the main doing 15 knots comfortably she felt great with this configuration but was lacking a little grip in the rudder department. There was far too much traffic to go with the kite so we thought we would wait until we got through the heads. Then she just let go and I thought we had just spun out. I then tried to get her nose back down wind and couldn’t. We looked behind and saw the rudder trailing behind us. The rudder was recovered and had a small ding in the leading edge half way down. At this stage, we don’t know if this was from the recovery or from the something at Nielson park. We dropped our sails and called for assistance on the race channel. I would like to thank the CYCA for their quick and professional response to the situation. The factory has been great and they are getting a new rudder out to us in the next couple of weeks. We are all looking forward to the Winter Series. Kind Regards,
Fix It Hi Nick, I am completely devastated to hear that your rudder has broken, specially after all the hard work that has gone it to get Stomp to the start line. I will write some notes here to make everyone aware of the design and construction process so we at least have an understanding on that. The structural design for the rudder and stock was done by composite engineer Wayne Smith. I was with him when he did the calcs and he even tested his model against the ABS and it was good. We have built two rudders to this design Serena and also the T37 in the US without any problems. So I am satisfied that the design is good. The exact same blade and stock size and laminates were used in all cases. What I suspect is the problem is the way we have built this rudder and stock. Generally the conventional way to build a stock is to laminate it over a male mandrel in one piece and then place the stock into a large lathe and then true up the bearings. The stock is then bonded into the two halves of the rudder blade. The process we used is different in that we manufacture the rudder stock in a split female mould and then infuse the two halves into their respective half blades. The the two halves containing the stock halves are glued together. We use a special very high yield glue for this. There are a number of things that I need to check to be able to make the finale assessment of why it broke, the main one being the glue joint failed, and check that the designed laminate was used. One of the problems with this setup at the moment is that because there is so much leverage on the rudder with the large wheel and undersized quadrant it is hard to feel what is going on with the rudder. One thing though, no matter what you do with the rudder as long as you don't hit any solid objects at pace the rudder should never break. Stompcraft will replace The rudders for the first and second boat. Once I have all the facts I will make the decision to start the replacement rudder, hopefully Monday. This will probably be sent within 6-10 days. We will check the laminate schedule and the stock size against the original design and then if this is OK will proceed to manufacture the stock over a male mandrel. I and Stompcraft offer our sincerest apologies for this. 04/05/06 |