The Wylie 66 has a simple two part bridle for both main and mizzen. On
the main, the sheet goes from the port cockpit winch through turning
blocks and conduits up through the house, exiting an interesting bell
shaped guide fitting in the top of the house, through a single block
on the wishbone, then back as a mirror image on the starboard side.
This allows trimming from either side. A bridle offers no advantage
over a simple 2-part tackle as installed on a Nonsuch. It is sometimes
used on dinghies because it acts like a much longer simple 2-part
tackle (the resultant vector of the two parts of the bridle as the
boom moves across appears to pivot well below the actual height of the
lower blocks) and this has an advantage for a low conventional boom on
a simple dinghy. Wylie did this just because it was a convenient way
to get the sheet to the coaming with fewer twists and turns. On the
mizzen, it keeps the sheet clear of the open transom.
On 'Anomaly', I used independent two part tackles (one to each side)
on both main and mizzen. It looks like a bridle system, but is not. On
the mizzen, this allows positive control of the position of the mizzen
boom at the cost of having to adjust two sheets. The advantage is the
ability to back the mizzen when backing down under sail, keep the
mizzen immobilized on center line while anchored or hove-to, and
things of that nature. On the mainsail I can set up both tackles to
keep the boom on centerline at anchor or while motoring in a sloppy
seaway, or hold it off center (usually to move the boom shadow off of
the solar cells, or while furling the sail). For both main and mizzen,
while close hauled the windward tackle is the active sheet and the
leeward tackle is the lazy sheet (and is slack). Once both are set up,
the rig is still self-tacking, there is no need to adjust the sheets
for a tack. Going from close hauled to a run, four sheets need to be
tended, except:
The main has an added twist: each sheet begins at the coaming winch,
runs forward to the mast, up to the boom and aft along the boom, then
down to the corner of the house through a floppy block and back to the
boom. This is a common 2-part tackle led aft to the winch via the
mast. But rather than dead end the sheet there at the boom, it turns
aft again, U-turns through a cheek block, and joins its counterpart
from the other side so that it is now just one line. There are sheet
stoppers on the boom to prevent the line from running through the
cheek block when they are closed. When closed, it acts as two
independent sheets as described above. However if the sheet stoppers
are open, the line runs though and now it behaves as a single 4-part
bridle system, trimmable from either coaming (so called "double-
ended"). We use it in both modes, depending on the situation. Running,
it is most convenient to use it as a 4-part bridle, because trimming
can be done from either winch and there is only one sheet to trim.
Close hauled, I can trim the boom closer using it as two 2-part
sheets, due to the angles of the tackles. Also while gybing,
manipulating the two tackles keeps very good control over the boom as
it gybes. The system works pretty well, though it requires some
thought at the beginning - most sailors coming on board scratch their
heads for a while. It also suffers from excess friction compared to
Wylie's system. That uses up a few more watts on the power winches
.
Jon Fitch
'Anomaly'
Currently lying Northeast Harbor, Mt. Desert Island, Maine