[malamar]

http://www.impossibledream.org.uk/idream.html

Mi heroe es este paraplegico con dos cruces del Atlantico ya realizados en catamaran..

IMPOSSIBLE DREAM : PRESS RELEASE 1st NOV 2001
Today sees the turning over of the hulls and bridgedeck structure of Mike Browne’s new 17.5 m
catamaran "Impossible Dream’ at the Multimarine yard in Cornwall. This all-carbon-fibre, fast
cruising yacht has been designed by Nic Bailey to meet all of the owners requirement’s for an
easily handled, fast, comfortable and responsive yacht for him to sail despite being confined to a
wheelchair. Although he has little intention of sailing the boat single-handedly, it was an underlying
requirement that all aspects of sailing, sail handling, docking, anchoring and maintenance
should be capable of being carried out by him alone.
Mike has been an active adventure sportsman all his life. He discovered sailing following a bad
skiing accident some years ago, since when he has raced 2.4 m keelboats, being well placed in
the Sydney Paralympics. He also sails a small trimaran and is well aware that the key to building
a fast cruising multihull is a combination of high power to weight ratio and easily driven hulls. It
was an early decision to build the boat in all carbon-foam sandwich, not only for the direct reduction
in shell weight but to set the philosophical yardstick against which all subsequent design
decisions would be made. There are a lot of features necessary in a boat that is to be managed
from a wheelchair that will inevitably drive up the weight, so the design challenge has been to
tackle each one with an open mind and a pooling of ideas from as many sources as possible.
The primary concept of the boat is defined by the ‘racetrack’ which runs around the perimeter of
the bridgedeckhouse. It rises gently towards the bow, and is protected by a hollow bulwark that
also provides stowage for fenders. At the aft end, the bulwark widens out to provide an outside
helm position from which all sail trimming, engine controls and navigation functions can be carried
out. The sail trimming from these positions applies to the mainsail and twin headsails, all of which
can be tweaked by means of hydraulic rams. Captive reel winches were considered for the headsails
but rejected on the grounds of size and weight. Instead the sheets are lead through the
coachroof to bridgedeck level where they go to hydraulic self tailing winches. These will not backwind,
and so a hydraulic ram operates a floating block in a bight of the sheet giving the external
helm position a 1m quick release. The mainsheet itself is also lead forward inside the boom and
down through the coachroof to a nacelle under the bridgedeck containing twin rams, a fine tune
and a larger bored ‘dump’ ram; whilst the traveller is controlled by yet another athwartships ram
hidden in the aft coachroof arch. Coupled with hydraulic headsail furling gear and hydraulic inboom
furling for the mainsail; the hydraulics systems do add considerable weight to the boat, but
this is the hardware that enables the boat to carry a racing size rig area, and more importantly
enable Mike to trim the sails, and thus really drive the boat, on his own. He has accepted that
hoisting and setting either the asymmetric spinnaker or the code zero, from the end of the
bowsprit, is something to be done by others, when on-board.
A lot of the time, the boat will be handled from inside the bridgedeckhouse. There is a forward
steering position, in front of the mast and behind a curved, laminated, toughened, solar reflecting
glass, heated windscreen. The wheelchair locks onto a small chassis mounted on traveller track,
which enables it to traverse the width of the cockpit giving the helmsman good access to all
instruments as well as both primary winches, but preventing completely uncontrolled movement of
the chair in bad weather. Bringing sheets and halyards below coachroof level inevitably means a
route for water to get in as well, although dorade type sheave boxes will keep most of it out. The
bridgedeck floor is dished towards the centreline and sloping aft, to make it as easy as possible
for whatever gets in to get out again. Because there was little point in providing storage at high
level, it has been possible to put a extensive glazing into the deckhouse making it as transparent
as possible. The only real obstruction to complete all round visibility is the mast support beam,
but even this has been given lightening holes to improve visibility."
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