Main Sheet and Boom
Media Store 
 |
For the main sheet,you can use any of
the "regular" methods shown in books for bermuda rigs. Often, a traveler
is used aft and the main sheet is dead-ended to it with an eye, shackle
or snaphook that rides along it. The main sheet then is rove from
aft to forward through a single block placed aft on the boom, then led
to another single block located forward on the boom (you locate this block
so it will be convenient to hold while seated in the cockpit).
For a dinghy, the traveler can be made like the gaff bridle, out of wire or rope, but has to come high enough to clear the tiller. You can secure the traveler to an eye on both port and starboard sides of the transom or rear deck quarter. This works well for sails up to 80 square feet or so. But for more purchase and easier handling, and especially if the sail is larger than 80 square feet, a three part sheet is best. To add the extra purchase, use a becket block on the end of the boom. The main sheet is dead-ended to the becket, rove down to the single block on the traveler from forward to aft, up through the becket block's sheeve, then forward to the single block on the mast which is located where convenient to grasp the sheet coming down from it into the cockpit. Figure C below shows this arrangement with a traveler. |
Knowing the Ropes by Roger C. Taylor |
A variety of methods are illustrated above
from Leather's Gaff
Rig Handbook, and he goes into some detail regarding the use of a mainsheet
horse, as in "C" above, that allows the sheet to relieve the sail of twist.
This helps windward performance, an important attribute for a gaffer, as
it can't sail as close to the wind as its bermudan cousins. On some
boats, the mainsheet horse is extended slightly outboard with ends returned
by radius to the bulwarks, allowing the sheet to extend past the sides
of the boat.
The boom is one area where weight need not be reduced, according to Cunliffe in Hand Reef and Steer. A solid boom is fine. It is low enough that obsessing about weight isn't necessary. My little Weekender Aslan uses a four part main sheet, not because the sail area is large enough to require it, but because I've changed the design to incorporate both a tiller and a stern hatch that would interfere with having a single block at the center of the stern deck. A drawing from Roger Taylor's Knowing the Ropes is shown below showing a way to make this. While this is from a chapter that doesn't deal directly with gaff rig, it does help illustrate that valuable information can come from chapters on "modern" rigging. |
 |
This arrangement works great. This
pic is from my personal
website. For Weekender builders, I include the model numbers
of the Harkin blocks used on the MSN
Community Weekender Boatbuilding, also accessible from messing-about.com's
Weekender
Boatbuilding pages.
I was concerned about the length of the sheet. Generally, as you increase the number of "parts" (lengths of line between blocks) you increase the length of the line. In the photo at left, you can count four "parts", the first coming up from the port side of the stern, the second going down from the block on the back of the boom to the starboard side, the third going back up to the boom, and the fourth going forward to a block on the boom you can't see in this picture. In practice, there isn't a problem with too much line. I have heard that it is awkward to use this kind of arrangement if you have wheel steering, as the sheet gets tangled in the spokes. |
[ Next
Detail Page ] [ Home
] [ Forums ]
[ Weekender Boatbuilding
]
