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Author: Brendan
Subject: Cabin-top sheeting
Info: (11085 views) Posted: Tuesday 1-10-12 05:11:53 PM
There have been several questions recently about sheeting (including cross-sheeting) to cabin top winches. As mentioned in these posts, several boats in SF are doing this. We started cross-sheeting on Get Happy!! after a long and painful upwind slog in the Ditch Run a few years ago, and have been pleased with the result.

We mounted 2spd Barient 18s on the cabintop, very near the aft edge of the cabintop and about centered on each side. They need to be mounted far aft so lines will clear the cabintop when cross sheeting. The Barient 18s provide plenty of power (as opposed to the single-speed Barient 10s we had as primaries.) The location on the cabintop is ergonomic, easy to adjust, and keeps people on the high side.

The primary disadvantage is that the cockpit is a tangled cross-sheeting hell and the "triangle" formed by the two sheets and the cabin-top are a definite no-go zone. Also, we have to strip the lazy sheet _every_ time we tack and set it up on top of the loaded sheet--otherwise when the loaded sheet is released, it falls on the new sheet and gets sucked in a tangle into the new winch. During tacks, only the jib trimmer (and helmsperson) can go through the cockpit, everyone else has to go around. And the jib trimmer has to avoid the triangle of death or they will become one with both jib sheets. Any one of these mistakes will be much worse than the what is saved by having the jib trimmer on the high side.

Also, cross-sheeting creates loads that the boat was not designed for and can lead to damage. We have not seen any signs of movement, but I've been told other Express 27s had problems. I _have_ seen other types of boats damaged by cross-sheeting.

All-in-all, we think it is worth it, but the jib trimmer definitely has to stay on top of things lest they tangle/override the sheets and/or themselves.

We have not removed the primary winches, and use them to hold Harken 57 airblocks on short climbing slings (just loop the slings with blocks over the winches). Thus, plenty strong enough for cross-sheeting. Also, we can pull off the slings and use the primaries, which we often do downwind. Or we can just go back to sheeting on the original primaries if we wanted to (light wind, family cruise).

If you decide to cross-sheet, beware: Here are some problems you may encounter:

- cross-over blocks will be under a lot of load, nearly 2x the sheet load.  They need to be stout and very securely mounted.  They may cause damage to your deck if not mounted properly.  They may cause damage to your crew if they break.
- cabintop winches need to be carefully remounted so the lines will run clear of all combings, and they must be of sufficient size for jib trim.
- big cabintop winches need to be used cautiously on halyards or you can destroy things.
- I've been told (but haven't seen) that some boats may have suffered structural damage from cross-sheeting.  When cross-sheeting, the boat is being loaded in a fashion it was not designed for.  Be aware that cockpit cracking, bulkhead damage, and other problems could occur.  Think carefully about the loads when mounting hardware, and stop your practice or make reinforcements if you see any signs of movement.
- if you use your winches for halyards, then you may have to fight for them at roundings (we have a dedicated halyard tensioner).  Careful coreography should avoid problems here.
- we have a little chafe on the combings even with a winch riser--you may find it hard to run all lines completely clear of the deck.

The class rules do not disallow the practice of cross-sheeting, so long as all parts and materials used are generally available and no modifications are done to the deck (other than drilling holes for mounting hardware). If you are trying something innovative, please ask if it would be allowed.

good luck,

--brendan
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