
The slewing potential
increases reaching speed, above. The larger design also
reaffirmed the effectiveness of Catapult's simpler design. |
As a one off development project, the 5.5m inflatable catamaran was
constructed by Jon Montgomery, with assistance from Topper. The
intention was to try out a larger version of the Catapult, as
well as to incorporate new technology allowing the hulls to
slew. The boat was hand made, utilising existing extrusions and
items already available for other boats.
The unique feature is the hull slewing - slewing 10 degrees pushes a bow
forward 20" but only reduces the beam by a few inches. It
was possible to slew the hulls whilst sailing, which shifted
weight and modified the waterline length. Alex Montgomery
comments that it was quite a strange experience to do this
whilst sailing, controlled via a block and tackle.
Around 15 degrees seemed the best combination.
To allow this, the cross beams are mounted higher, (see photos below).
The centre of effort of the sail moves when the hulls are
slewed, so the 5.5 has swivelling centreboards to bring the boat back into
balance, rather than dagger boards (see
Alex at speed singlehanded further below.)
The boat had two rigs. One was a 2 piece Tornado mast (cut down &
re-wired) carrying 13 sqm sail.
The other is an A class rig, a 9m one piece aluminium wing mast with
tapering top section carrying a 13.9 sqm Dacron sail with foam
battens.
A 7 sqm storm sail was also used at Speed Week.
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