In search of Speed….
Building a boat is an ancient art. Our ancestors discovered that lashing tree trunks together would get you afloat and at some point after that discovered that purposefully shaping those timbers made things significantly easier to paddle and probably soon after that, that removing weight allowed more warriors, or fish, or livestock to be carried across water. Better technology was just under the surface at every stroke.
Paddling is hard work and difficult on a swell yet the wind has always been free. The first sails were made just to catch the wind. Later someone figured out how to curve the wind and sail across the breeze and the better they did it, the faster the boat would fly through the air and cleave through the water.
First one home with the fish gets the best price is how it sailboat racing began. Maybe before then, ‘First boat home beats the storm’ was an even higher prize? I wonder if in ancient communities, those men with an eye for a line, with the patience and skill to shape timber, with the instinct to feel the way the ocean would be parted around the bow or the way the wind would fill a sail, selected themselves as the most skilled artisans and craftsmen.
Through the ages on every continent, in every period of history boatbuilding has been at the essence of technology and behind the historical headines, reputations and livelihoods were made by building faster boats, feeding a desire to skim across the water for trade or commerce or competition or indeed conflict.
Project Speedbird is our dream, the result of two friends; one an ambitious adventurer, one an aeronautical enginner, turned boat builder. With a one-off boat, a huge amount of skill and determination, we intend to set new speed records. Break barriers. We’re aiming at the ultimate in speed sailing; the Women’s record for the Nautical Mile.
The project is technical and demanding and requires the boat to be ahead of the game and Hannah White, the sailor at the helm, to be right on top of hers.
Sailing a small boat at 20knots is like driving a car at 50mph down a bumpy track – total focus is needed or you’ll spear off into the bushes but probably get away with minor damage.
Imagine a Group B rally car at 100mph on an ice stage. Spray, poor visibility, sliding and gripping at the same time. A sailing boat at this speed is a beast. A runaway train accelerating downhill in it’s own breeze, travelling faster than the wind – and all the time one slip can mean the whole thing hitting the water and probably a hefty repair bill. Carbon is strong but a 6g deceleration is a force to be reckoned with.
The forces are exponential. The wind speed is now around 50mph across the deck. The same as above but louder. The rally car without a windscreen.
Low 40s… All we can say is, it’s going to be worse – and better. We just don’t know how much worse. We haven’t done it yet. Our new frontier.
A few windsurfers and kite surfers have cracked 40 but only a handful of people have sailed boats at speeds like this. All will remember the first time the readout clicking over from a 39 to a 40. To keep control of the whole thing and hold that speed for a nautical mile? It’s a very big ask from boat and sailor.
So, the boat – State of the art, carbon fibre, F1 technology…. If you know anything of competitive vehicle sports, you’re expecting that paragraph…Well, not this time. Not that one.
Carbon fibre was commonplace in hulls and masts in sailboat racing from the early 90s (I can recall building a mast for a customer from what is now considered in cycling to be ‘cutting edge’ High Modulus fibre, back in 2001) and indeed the first carbon fibre monocoque racing boat in the World, a trimaran called Colt Cars, was built on the Isle of Wight in 1980 – a whole year before McLaren used a composite safety cell in it’s F1 car and three seasons before it’s all conquering MP4/1c and the end of an epoch as F1 constructors finally gave up on the riveted aluminium monocoque.
High performance racing sailboats are not built from ‘F1 style carbon fibre composites’. F1 cars are built like high performance racing sailboats. It would be undermining to our sport for an actual cutting edge project to sound ‘star-gazy’ at these materials. They are our building blocks. We use them all the time from production, off the shelf dinghies to 100ft long ocean racing maxis and everything in between.
So, what IS so special about the construction of the Speedbird? Well the clever thing is not only the speed at which it will travel, but the speed at which we can build it. The boat needs to develop quickly as we approach those frontiers because quite simply we don’t know exactly what the subsurface hydrofoils will be like – We have parameters from our design work, and we have the best sections supported by data we can access – but there’s the finer detail which needs to be able to evolve – and evolve quickly.
David Chisholm Technical Director, Project Speedbird ‘The water on the top surface of the hydrofoils will be under such low pressure as we approach our maximum speed that it will boil. When it does it releases gas and that gas pocket sits on top and behind the hydrofoil but is much larger in volume and so than the frontal area of the ‘foil and it acts like a brake. As the boat slows down, the gas bubble (we call it ‘Cavitation’) disperses and the boat can accelerate again.. We will be able to reach that speed all day long but not pass it. Like a rev limiter in a racing car engine.’
The technologies we are employing means we can build the speed seeking hydrofoils we need in a matter of hours not days. How? We start with the premise that Speedbird is a one off and not a production boat. To build quickly we need a way around both the design testing stage and the time consuming tool making process.
Computational Flow Dynamics (CFD) software takes days to run, wind tunnels and tow tanks even longer when you consider the model building programmes… So we’re not doing them. The boat is set up to be it’s own test rig. We use sensors and telemetry to get the data quickly and we use cameras to capture a lot of flow information on sails and the hydrofoils.. Then we develop the parts we have, and refit them, or we make new improved parts…
To do that last part quickly, instead of machining master patterns in aluminium and from those, making carbon moulds to withstand the cure temperatures as would be the ‘traditional’ route (taking days per part) we’re cutting directly into a very high temperature low density foam, moulding the part, breaking off the mould (it becomes extremely brittle at the cure temperature required by the carbon) and then passing the 3D CNC controlled router back over that part to remove any residue from the temporary mould. A sacrificial layer of a particular recipe has been developed to treat the mould surface and from the tests we’ve done the parts are accurate and have a great surface finish.
DC Says, ‘It is quick. Nearly as quick as 3D printing for some parts – but instead of a brittle 3D printed plastic part, we can make high modulus Carbon parts, with the fibre where we want it – and at a fraction of the cost’
This process means development can keep up with the Speedbird programme and help it to go faster. Our frontiers are real and our solutions must be just as practical. Designing the whole thing in a virtual world and doing half scale testing introduces delay, inaccuracy and cost. We prefer to use our boat building skills which we can rely on more heavily. We will be using state of the art CAD design and CNC machining, but in a very dynamic and new way.
So, yes, the boat itself is pretty regular as far as we’re concerned – titanium fittings, modern rope materials like Dyneema and Cuban fibre and we’re using super high modulus carbon fibre for the hull and mast – which is normal for sailboat building. And yes, the sails will be carbon reinforced membrane technology – which has been around for at least 15 years which was picked up by F1 teams in 2012 as a clever way to make aerofoils… and we do share most of our technology with the most technically demanding competition in our sport – the America’s Cup… But then, the boat we’re building will be travelling a little bit faster than the ‘Cup’ boats, even in the hydrofoiling age.
So, F1, AC Boats, even state of the art Range Rovers all use similar technology, identical materials, and learn from each others development, but we are by no means copying… we are trying, testing, pioneering, and hopefully are ahead of that game. After all boatbuilding is an evocative and ancient trade. An unbroken history of design and development, constantly in tune with materials, technology and the environment, since man first sat on a floating log and thought, ‘This beats swimming’.
- Next s