boom mainsheet block

[Gee Are]

Hello,

I have seen a few of photos of Seaspray Catamarans.  Some of them show the mainsheet coming from the boom.  I am interested in mid-boom mainsheet block.  Who makes the block used on this system?  I have not seen any closeups of this block.  Does it have a cam?  How does it attach to the boom?  The reason I am interested is I sail a Prindle 18.  About 25% of the time I sail it with a set of factory wings.  Every time I put the wings on I have to adjust the cam angle on my mainsheet blocks.  Then re-adjust them when I ail without the wings.  I have looked at some A-cats with mid-boom blocks but the ones I have seen are feed from the mainsheet coming up through the middle tramp.

Thanks in advance for any info and photos.

Greg

[Don]

Hi Greg,

It is a Harken product called a Pivoting Exit  #140 or 141 if you want Carbo-cam.  I am not sure how well it will work on a Prindle 18 as your mainsail is much larger than a Seaspray.  You may want to reverse the cam blocks depending where you place it on the boom.  It is attached to the boom with three SS rivets and can be removed from the attachment plate by removing the pin and ring.  For those of us using this boom end sheeting system the advantage is not having to pass the tiller around the mainsheet block as the traveller rope is attached to the transoms on each hull as well there is a considerable weight saving.  There is also less rope to deal with as we use a 2:1 block system as opposed to the typical 4:1 block system mounted about 2/3 of the way along the boom from the mast.

Don