From Conor O'Brien's "Sea-Boats, Oars and
Sails"
<> Gaff Rig Ideas
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It's well worth finding this little book. O'Brien
was a cruising yachtsman who sailed around the world -
he also ran in one Fastnet Race with his yacht, which
was rigged with a square sail. He didn't win, but
apparently he had an interesting time. In the book he
diagrams how to rig a small boat three or four ways,
using the same hull and the same sail area, keeping
everything reasonably small and low. Here are a few
examples. I've omitted his Standing Lug and Spritsail
drawings as they aren't anything out of the
ordinary.
Now of course you don't need to re-rig your boat,
but these ideas are simple, cheap, and based on his
seagoing and Channel-cruising experience, meaner stuff
than we're likely to encounter with our
day-cruisers.
Note the vang on the gaffer. Vangs died out
sometime in the 1800s and are all but unknown to
yachties but in old paintings and drawings vangs are
used all the time on spritsail rigs and gaff rigs; the
vang controls the end of the gaff and helps prevent
sagging in going to windward. It also controls the
gaff when running before the wind.
In his days gaffs were heavy. On a small boat, or
in a more modern mode, we can consider using bamboo,
aluminum tubing, or some sort of carbon fiber. I keep
wondering about scrapped carbon fiber windsurfer masts
as yards or gaffs.
Conor also hated booms. I think we can probably use
both a boom and his rigging ideas. I'd consider, at
least, experimenting with a light boom and battens at
the reef points if I went to rig a boat following his
advice. But that's another topic.
Gaff or
Yard
A removable sail. The peak tie loops
over a groove at the end of the spar and
through a hole. The halyard passes through
its own end and sits between wooden chocks
(this could also be a block of wood with a
hole in it; a comb-cleat). His diagram shows
the anti-jamming "forth and back" lacing on
the mast.
The small diagram shows lacing the head of
the sail to the boom with individual loops of
line.

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Halyard
"It is curious that none
of the examples which survive in England
-- bawleys, Itchen ferry boats (probably
extinct), Plymouth hookers, and their
like, take advantage of vangs to make the
sails set on a wind, and that they all use
two halyards where one will do. The
30-foot gaff of the Norfolk wherry, which
has to be cleared away and got up again
when the mast is lowered for shooting
bridges, is hoisted with a single halyard;
so is the smaller gaff of the whaleboat
used in the Azores. In the Norfolk rig, as
simplified for a 10-foot gaff (Fig. IVa),
the halyard leads through a masthead block
down to a single block on the gaff jaws,
up to another masthead block, and is made
fast to the peak; since there is a
two-to-one purchase on the throat and none
on the peak, the luff of the sail is
stretched before the peak is set up."
I use this arrangement on a lug sail yard
and it works very well at keeping the yard at
the proper angle, and firmly in place. It was
written up long ago by George Holmes in
connection with lug-rigged canoe yawls but
Conor is writing with reference to
'wherries', gaff riggers which sailed on the
Norfolk Broads in England. He was writing in
the 1930s so the line from the lower block he
calls wire rope. We can use Spectra line or
prestretch Dacron.
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Halyard
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Want
a topsail? Try this.
"I said it was probably
easiest to lower the mainsail right down
to reef it ; let us try lowering it right
down to set a topsail over it.
"The topsail is bent to a yard the
whole length of its luff, and the heel of
the yard hooked to an eye on one side of
the gaff jaws, and a rope becket on the
clew of the sail slipped over the peak of
the gaff. The yard can hang from this
while the mainsail is being hoisted, then
it is straightened up by the halyard,
which is the only extra rope aloft.
Lowering would be easy if the topsail were
to leeward of the peak halyards, for it
would fall down into the lee of the
mainsail ; not quite so easy if to
windward, and it might be desirable to
have a line bent to the yard to haul it
down on its proper side of the gaff. This
rig has the merit that the lightest part
of it is on top, and the biggest topsail
can be very large and light indeed."
He admits he hasn't actually tried it, but
as he says, there's no reason it won't work
on a small boat. The topsail halyard is a
long line which stays rigged through its
sheave.
If you add an extended yard to the bottom
of the topsail to make it stick out beyond
the gaff, you'd have a "jackyard topsail". No
reason this same scheme would not work for
such a topsail.
Now the vang on the end of the gaff
becomes a topsail sheet. Hmmm. Clever.
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Gunter
Sprit Rig
Ah, his "favorite rig". This he
calls the "gunter sprit" but it's practically
identical to the "pound-net sharpie" sail
described in Chapelle's American Small
Sailing Craft. Again the "vang" or "mast
rope" is essentially an upper sheet. O'Brien
doesn't like booms, but these rigs work fine
with booms. If you add battens along the reef
points you wind up with something very much
like Commodore Munroe's sharpie sail plans.
The "sprit" is rigidly attached to the
jaws so it won't foul the mizzen mast, and
the upper leech keeps it at the same angle
when the gunter yard is hoisted. The gunter
yard could swivel on the jaws so that stowing
the sail becomes a simple matter when the rig
is off the boat.
"Since the sprit always makes the
same angle with the mast the end of it may
come within an inch of the mizzen mast and
still never touch it, whatever height it
is hoisted to ; therefore it completely
fills the space between the masts, which a
gaff sail cannot do. A rope is made fast
to the mizzen masthead, rove through a
thimble [block, or fairlead --
COD] on the end of the sprit, and
belayed at the foot of that mast ; the
sprit, sliding up or down this mast-rope,
is under control all the time ; it is in
fact the main sheet, for it takes most of
the weight off the clew of the sail.
"I have tried out the principle on my
twenty-ton yacht, not indeed with a gunter
sprit, which I am only recommending from
personal experience as a boat's sail, but
with a gaff and topsail of just the same
shape ; and I found trimming sail absurdly
easy. With a single-part mast-rope I could
pull the gaff flat amidships when a
yachtsman's gale was blowing, and a single
whip on the clew was ample for the lower
sheet. The peculiar advantage of the
gunter sprit is that in reefing you have
only the halyards to look after, the rest
looks after itself. When the heel of the
sprit is right down on the thwart there is
only about 6 feet of the leach of the sail
loose, as I have drawn it, and less than
30 square feet of sail area ; the weakest
man could hardly fail to get hold of the
close reef cringle and secure it, and I
should keep a lazy sheet made fast to that
cringle to make it easy to catch."
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Three
knots
...of those he thinks you should know. The
Stunsail bend makes the smallest glob of line at the
spar of any knot, he says, so it won't hold the yard
away from the sheave or block. The Topsail Sheet bend
is something fun to know. I just like the drawing of
the anchor.
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to Odd Sails
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