Graham Cox wrote:The sister blocks I use on my sheet spans are small stainless steel Ronstan blocks, with a fixed flange that has a small eye in it.  I just overlapped the flanges and bolted them together using a nyloc nut.  These sister blocks, being rigid, are the nearest thing to a euphroe (correct spelling?) possible and work brilliantly with no twist, friction or chafe.  I have posted a couple of photos of them in the Arion details album in my member albums.  I don't know how to paste a link in here so you will have to go and look for yourself.

[Webmaster edit: Here's the link, Graham.]

David Tyler wrote:

Gary King wrote:

David Tyler wrote:No, don't use a swivel head fitting. It just puts in more twists. The twists occur when the mainsheet itself has twisted, and the only solution is to go to the free end of the sheet and rotate it so that the turns are taken out. It occurs naturally over a period of time, even with the best-balanced rope.

Would this be the block for sheet spans?

It looks like a solution, but unfortunately it's only good for short-term use, the span chafes inside the loop. Without going to the trouble of making custom hardware, the easiest solution is to buy two fixed eye blocks like this, a large one for the sheet, and a smaller one for the span, and shackle them back to back. Do this in the store, so that you can find a shackle that fits.

David Tyler wrote:No, don't use a swivel head fitting. It just puts in more twists. The twists occur when the mainsheet itself has twisted, and the only solution is to go to the free end of the sheet and rotate it so that the turns are taken out. It occurs naturally over a period of time, even with the best-balanced rope.