happy to be proven wrong. While beating down the English Channel we were able to tack through some 90-95° (made good) in 22kt TWS. Boat speed was in the 10-12kt range and the ride remained extremely easy and comfortable.
Despite later surfing down long waves at speeds of up to 27-28kt during the crossing of Biscay, the striking contrast between the excitement and exhilaration outside and the calm inside was, I felt, extraordinary and is quite unlike on any other boat I have experienced.
And so the general principles that now fuel our optimism about the future development of ‘Premium Catamarans’ are as follows…
Leaving aside the maths, if a narrow single-hulled boat is heavily laden with cruising gear and equipment the hull resis- tance will obviously increase and yet the righting moment may see no change – or it may even be reduced – by the added burden. If the same mass is added to a wide boat (and a catamaran is a very wide boat), and if that mass is assumed to be centred near the centreline of the boat, then it makes a considerable additional contribution to the RM (added mass x off- set between centreline of boat and centre of buoyancy of the leeward hull). Historically, however, the average cruising catamaran has not been equipped with a rig and rig-handling gear to exploit that increased RM so, as with the narrow- hulled monohull, more weight simply means a slower boat.
What has changed is that the technology is now available (at a price) to allow a ‘Premium Catamaran’ to turn that additional weight into power – which goes a long way towards cancelling out the detrimental effect of the added burden. Allegra is simply enjoying the benefits of a ‘cutting-edge’ set of spars (from Future Fibres) and sails (from North).
A quick look at a car of equivalent stature would reveal that there’s much more to making it fast than simply fitting a powerful engine. Allegra gets the most out of that rig by the use of the best possible deck-handling equipment (from Harken and Cariboni).
The underlying ‘chassis’ – the founda- tion on which all that gear depends – is the work of builders Green Marine, whose experience in the building of lightweight carbon structures is key to the success of the whole project.
A racing multihull of the same size as
Allegra would obviously be much faster, but the added weight found on a cruising catamaran like this also plays a vital role, by a happy coincidence, in making the movement of the boat smooth and com- fortable – which is clearly essential in the context of cruising.
Writing in praise of a ‘heavy’ multihull is not something I had imagined I would do, but based on the experience so far I must confess to being really excited about the future of this technology…
32 SEAHORSE
Diamonds are the mast’s best friend – Torbjørn Linderson The evolution of the modern High Perfor- mance Cruising Catamaran over the past 10 years has centred primarily around the 60ft range, an evolution that has resulted in boats that are both enjoyable to cruise as well as great fun to race. Moving for- wards, however, we will see the next important trend squarely at 78ft, the maxi- mum length of vessel to which the current EU ISO rule can be applied. Above this size designers will be facing much greater demands in terms of certification… and thus load-carrying ability.
First one out in this new wave is the Allegra 78, designed by Nigel Irens and built by Green Marine. The main charac- teristic of the boat is a focus on waterline length in combination with a relatively narrow beam, plus an emphasis on con- taining moderate weight rather than max- imising interior space. This is combined with a healthy 33.5m spar promoting hull flying rather earlier than on most of the
current crop of performance cruisers… While Allegra will not fly a hull as early as a pure racer. The powerful rig and the fact that it is engineered for full hull flying – even on a boat that has outgrown the 70ft range – have raised more than a few eye- brows. A more moderate rig, engineered for a maximum apparent wind speed, would by contrast have delivered a yacht that, while being impressive in windy conditions, would have a hard time keeping up with a modern high-performance monohull. With a large mainsail and a rotating wing mast Allegra is quick enough to per- manently douse nylon sails in favour of a Code 0/A3 sail for VMG work, providing enjoyable high-speed apparent-wind sailing rather than the monohull style of ‘deep’ approach that is typical even for many relatively fast cruising cats. Meanwhile, dynamic safety onboard is maintained by a comprehensive system using load cells to warn the crew when approaching certain levels of utilised RM as well as heel angle sensors for instant release of the sheets.
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