[Public-List] cabin top traveller

[Don Campbell]

Hi Walter:
     This is about your comment to go to a cabin top traveller. Really consider the forces you are changing when you think about doing that. Firstly: you change the moment of the force on the boom from now 14’6” to about half of that. That means you will double all the other force requirements for the track and blocks, gooseneck,  and boom. So if you are now happy with the designed 4:1 on the main , you will have to go to at least 8:1 for the same pull on the sheet.  It will also mean you change the forces on the boom, mast track,  and  the sail itself. In fact getting a method to hold the connection to the boom for the mainsheet blocks without compromising boom strength and still able to withstand the extra forces is a real challenge. When a boom breaks in half, it is not a very pretty situation with sail and boom end flapping around your head. Secondly: The cabin top has not been designed to take the upward force that this proposed change will incur. While the builders have not known what fiberglass would do, so they overbuilt things, changing the structural component to try to do this change was not a part of the design or serendipity that we have enjoyed with a strong hull (which is different from the cabin top and deck). Thirdly: you will change sail shape and have a leech that will always be open because you will lose control of the end of the boom, This will offer more opportunity for a luffing leech and that is not an easy sail for power.  Lastly, you will have made the boat not class legal and so it can never be sold to anyone who might want to race her.

    I have no idea why one would want to change the traveller position, but if it is because the original equipment is slow, sticky or just awkward, then consider changing to a new track system and leave it where it is now. Hardware manufacturers do a really good job now of making things so they work in all conditions, and I know we have Albergs with new gear on them. I put Harken on #528 twenty  years ago now and I still like the system. I know others who have used Garhauer and they like that too. Really consider the change at boom end. I am also sure that if Carl were alive today and designing boats, or even commenting on refits, he would be using today’s hardware because it is functional , well built and safe.
Don