Inner
Forestay for Storm Jib on sloop-rigged boats
The
following advice was provided by Bob Hathaway in response to a query by
Lesley Whitfield and Paul Brittain who wanted to be able to use a storm
jib on their sloop-rigged, Victoria 26, "EverGreen". Bob provided
this response by e-mail on the 9th May 2004.
Congratulations
on your purchase of a Victoria 26. I owned one for many happy years
before and during my employment with Victoria Marine / Yachts.
The
inner forestay should be made from 5mm 1x19 wire with a matching bottlescrew
or (better) Wichard quick release adjuster. In the ultimate analysis it
will take over all of the load from the outer forestay and the chainplate
should be sized to suit the breaking load of 5mm wire. The normal
practice is that the chainplate has a design breaking load twice that of
the wire attached to it.
The
exact psitioning of windlasses on V26s varied with the mood of the deck
fitter, but typically you should be able to fit a deck padeye about 150-175mm
aft of the chain locker bulkhead. If reality is different to this
then please come back to me. With the design that I am describing
below, the closer that the padeye is fitted to the bulkhead the better.
Buried
in the laminate of the V26 deck is a 300mm wide "king plank" which will
take care of any through deck compression forces, so the padeye can simply
be bolted through to the chainplate described below without any need for
compression spacers or ply backing plates to spread the load.
The
anchor windlass backing plate should be replaced with a bracket in the
shape of a T with the vertical leg of the T braced with gussets aft to
the line of the padeye. The vertical leg of the T should be made as long
(vertically) as possible and consistent with the anchor locker hatch. There
should be a matching backing plate for through bolting through the bulkhead.
The entire assembly should be fabricated from 6mm stainless with a minimum
of 6 x 8mm dia bolts through the bulkhead.
This
deals with everything apart from the risk of the bulkhead failing in shear
or torsion. This is resolved by creating a GRP girder both sides
of the bulkhead by laying up a 6mm thick L between the bulkhead and the
deck, as deep as the space above the hatch for the width of the hatch but
increasing to 150mm outboard of the hatch to the hull sides. The
laminate should be taken round onto the hull sides both forward and aft
of the bulkhead to create a 3 dimensional structure. I would suggest
that epoxy resin and cloth would be stronger than polyester and mat and
it would be easier to achieve a good bond to the hull and bulkhead with
epoxy. Obviously, the laminating should be done prior to templating
the new chainplate.
The
resulting structure, with 8mm Wichard Padeye will be strong enough to lift
the boat with, which is, by the way, a pretty good way of assessing chainplate
strength! If you buy the double padeye you will also have a tack
attachment for your storm jib.
Having
prevented the deck tearing off, you also need to prevent the mast falling
down by fitting a pair of light (4mm wire or 6mm Kevlar) running backstays
to a pair of padeyes well aft. Because of the hull to deck joint,
a pair of simple 8mm U Bolts with backing plates through the toerail and
hull/deck joint will be strong enough. |