|Windjet Water Craft|
Important - The Windjet project is currently not developing their water craft. Since initial trials in Weymouth during winter of '04, we have not put any time towards the development. This is not due to lack of performance, far from it. (Check out the craft in action at 30 knots, offshore over large chop) The main problem was speed of evolution. With only one or two (favorable weather) sailing days a month at Weymouth, you just do not have enough time at speed to evolve the craft. To speed up this development, you must go to a warm beach with reliable, daily breezes and a team permanently on site, which leads to the second problem of financial resources. Trying to challenge three, separate and difficult world records simultaneously, is just far too demanding without proper funding.
We therefore decided to focus on the land and ice records before we will return to the water craft development. However, for your interest, here is a brief glimpse into the research and progress made so far;
So How does it work?
The concept uses the 'inclined rig principle'. This in NOT a new idea and people have been playing around with the idea since the 1930's.
Instead of needing forces (usually static weight) to counteract the heeling moment generated by the rig, the inclined principle eliminates the heeling moment by realigning the forces. With no heeling moment, there is no need for a heavy craft, so the boat can be light and the lifting surfaces (sail and keel) can be high aspect (efficient) and pull far greater forces.
Three of the current main competitors (Monofoil, Trampofoil and Sailrocket) use this principle. Macquarie uses a more traditional vertical rig, while the windsurfers fall somewhere in between.
The key to success of using the inclined rig is the practical configuration of the craft and how the various lifting surfaces deal with the rapid accelerations. Getting a craft to operate at a steady speed is relatively simple. Getting a craft to operate at a range of speeds, from zero to 50+ knots, through violent accelerations, while maintaining a stable course, elevation and pitch, is far more complex.
The majority of Windjet's research went into this evaluation, with hundreds of small balsa models, to overcome a number of hurdles.
The craft that we produced is far from the ultimate design that we identified. Instead, it's design criteria was a stable platform, on which to evolve the rig and water foils, while getting some high speed experience. The biggest problems are often unforeseen and only begin to occur when nearing the final 10% of the boats potential, so it is very valuable to get some high speed experience before building the final itteration.
During Weymouth Speed Week
in at 160 kg, the craft can pull over three times its own weight, which
means becoming airborne is a real issue if you get it wrong. However it
is designed to recover, as has already been proven in a couple of
initial airborne adventures!
Leaving the workshop
Sailing in Light winds in Weymouth Harbour
Windjet Next to Sailrocket in Weymouth Harbour