DaySailer.org Forum

the 'old style' mainsheet system had the sheet dead ended on the end of the boom, then through a turning block on the aft deck corner, across the rear deck to a turning block on the other aft corner, back up to a turning block on the back of the boom, forming a triangle, and then forward.
my recent acquisition has a rope traveller across the rear deck with the mainsheet deadended on a block with a becket on the end of the boom, down to a block that slides on the traveller, back up to the block on the end of the boom and then forward.
what system do you prefer/recommend? what are advantages of different systems?
thanks
dan in port royal

I've never used the old triangular system, but one advantage of the stern traveller is that you can put secondary lines on the traveller block to adjust the angle of the main sheet. When pointing in light or moderate winds, this lets you sheet the boom in close to the center line without flattening the sail. In heavy winds, you can set the traveller block amidships or let it drop all the way down to leeward. This increases the downward pull of the main sheet and spills some wind from the sail.

I suppose another (questionable) advantage is that you can easily change the block configuration if you want more mechanical advantage. I experimented with double fiddle blocks on the stern, but with a ratchet block on the main swivel, they weren't necessary, and I had a ton of hardware dangling on the end of the boom.

I went to a midboom 6:1 system and am very happy with it. You need a triple block and a triple with a becket

Dan,

I did some testing last year with different sheeting systems and the bottom line is stick with what works for you. Here's what I did and my opinions on each:

Crosby- This is the original setup (rear triangle) on early Odays. The 3:1 seems to be the right amount for me. It definitely loses some in pointing. On runs it takes more line than mid boom. Jibes have to be thought out more as well. If you have a motor it can get fouled, I don't and it has never fouled on me. It does distribute the load on the boom.
Side note: I used the crosby on a Mariner for quite a while with ratchet blocks on the transom corners this allows you to pull it near the center line. Really is quite an improvement.

Mid boom sheeting fixed to the centerboard: This has a lot of advantages of convenience and makes jibing easier since you can grab all the lines and pull the boom across. Doesn't point any better than the crosby. Does pull the sail down and in, more than the crosby and certainly more than a traveller setup. Definitely makes for more cockpit room and is almost foul proof. I have a mid boom on my Rhodes and it works well for that.

Stern traveller: The only one I tried is the single line type where the height is fixed and you can let it out or pull to center. Works well and can help pointing by pulling it to center. If the winds pick up you relase some line on the traveller to reduce heel. Distributes load like the crosby too. Has the same jibing issues as the crosby. This is what I see are on most of the NACR racing DS's or the more complicated type where you can adjust the height too.

Mid Boom traveller: I saved this for last because I know least about it, what I did was definitely makeshift and I only tried it in light wind. The biggest advantage? with this is you can pull the traveller to weather. When I did this the sail just stalled. It also makes the cockpit almost unusable in my opinion.

Ultimitely I left the original crosby for simplicity purposes. If I was to make improvements I'd still keep the crosby and use the ratchet blocks, I liked that setup. Since I don't use a traveller I do vang sheeting to control the boom height.

Fred
DS#1351

thanks for the very helpful posts. i'll probably keep my stern deck 'rope' traveller at least for a while...

I switched from rope triangle to rope traveler and honestly can't remember what difference it made, if any. Possibly, it's slight, or I don't know how to use the rope traveler optimally, or the sails were too baggy (at the time) to allow any comparison. Now that I have the rope traveler, inertia demands I keep it

A note on the ratios. If the mainsheet were lead, not ot the cleat on the CB trunk, but to some hypothetical cleat on the transom, you would have a true 3:1 reduction. Because of the way the end of the sheet is lead to the middle and then to the CB, the ration is only 2.5:1. (At the mid-point any sheet has only 1/2 the leverage as it would have at the end)

A mid-boom 6:1 purchase, is then only equivalent to a 3:1 purchase at the end of the boom, however, it has double the losses due to friction. That means it's actually only a few percent more powerful than the end-boom setups.