Left: Cringle
hand-work
at James
Lawrence;
Ketch Analía
with sails by
North; finishing
on Eilean by
North; Spirit
Yachts use
laminates by
OneSailsNEW MATERIALS ON OLD RIGS
Some classic boats in the Med race under the rating rules
of the Comité International de la Méditerranée (CIM),
which penalises the use of the most modern materials.
Many more yachts race under the IRC rating rules. This
does not recognise sail materials in its assessment of a
boat’s handicap, so in theory wooden boats can be fitted
with the most hi-tech, performance-oriented sails. Flying
sails so stretch-resistant, on modern halyards offering
little give, can place an unnatural load on an old wooden
rig. Big sailmakers now have their own software
applications that allow them to calculate rig loads in
advance, but Lastra says: “Obviously the results are
accurate for modern materials, however when we work
with old materials, there is a degree of estimation
involved in our calculations, since it is difficult to have
reliable values when working with wood 50 years old.
Contact with the captain, crew and owner becomes
crucial for success as these people have much
information that is not contained on the sail plan.”
Jeremy White of Elvstrøm concurs: “Wooden spars
have a mind of their own. Bend characteristics can
depend on how well the wood has been looked
after. If the rig has been left badly set up for a
number of years, then strange shapes can be set
into the spars which can take further years to
change back. You cannot tension a wooden rig
as highly as aluminum spars. If a boom or mast is
soft and bendy, this has to be calculated into the
cut of the sail, or the sail shape will look ugly.”
Things to look
for on your sailsBy Richard Dugdale of Jeckells
Rope shrinkage
If you have a sail with rope in the luff or foot, over time that rope can
shrink, altering the shape and aerodynamic properties of the sail, and
not fitting the spars correctly. Look for wrinkles coming from the luff or
foot that cannot be removed by tensioning the halyard or outhaul.Leech wear
The genoa leech is often the first thing to go on any sail, if it is left
exposed on a furler. If the leech starts ‘motoring’ on a modern yacht,
you can move the genoa car forward, but on most classic yachts with
fixed fairleads you can’t adjust the sheeting angle. A flapping leech will
decrease the sail's life and you’ll end up with disturbed air on the main.Fullness of the sail moving aft
Over time you’ll notice the boat heeling more, you’ll have more leeway,
more weatherhelm. Take a photograph from deck level, looking up, and
draw a straight line across the photo from luff to leech. If the sail does
not hold a fair elliptical curve then it needs attention.Stitching
UV degradation and chafe are always an issue, although braided UV-
and abrasion-resistant threads are available that cost more but do
increase the sail's life. Consider having the sails valeted before the
season. Remember the old adage – a stitch in time saves nine...One classic yacht flying modern sail on wooden spars
is Cetewayo, the 1955 Laurent Giles sloop owned by
British Classic Yacht Club Commodore David Murrin.
Disappointed by the lack of wooden yachts to race
against regularly, Murrin set about upgrading Cetewayo
over the 1990s so that she could race competitively
under the CHS (Channel Handicap System), the
forerunner to IRC. As part of this, in 1995 Murrin
replaced the Dacron sails, initially with white Mylar sails
built by Doyle and then with Kevlar sails from Rellings.
This was probably the first time a classic wooden
yacht had fitted the new high modulus [stretch-resistant]
sails available and many observers expected the boat to
be pulled apart by the resultant shock loads. However,
Murrin argued that such sails would undergo less
deformation and stretch, thus maintaining the power
generated as a forward-driving force rather than a
heeling moment. “As Cetewayo is a long, narrow boat, it
would be easier for her to absorb a driving-forward force
than a heeling moment that constantly puts stresses on
the narrow lateral rigging and down into the garboards.
Also, the high shock loads developed by high modulus
sails would be partly absorbed by the more flexible
wooden spar, and the use of traditional sheets.”
This thesis proved to be correct and Cetewayo
was raced extensively without incident for 20 years.
In 2015, however, she had fitted a taller and stiffer
Douglas fir mast, and since its addition, there have
been some signs of minor additional stress to
Cetewayo’s hull. This suggests the shock loads induced