vol 8, issue 6

F1 powerboats - full-throttle technology

17 June 2013
By Sean Davies
Share |
An F1 powerboat crashing

Advances in safety mean that during a crash the equipment takes the impact rather than the driver

A F1 powerboat speeding across the water

The top speed of an F1 powerboat, despite improved acceleration is the same as an F1 car

Price and Jones at the UIM F1 H20 Powerboat Grand Prix of Ukraine, July 20-21, 2012

Jones (right) and ex-world champion Jay Price

An F1 powerboat accelerating

A powerboat runs on a cushion of air with only about the last 5cm of the boat making contact with the water

Sir Henry O'Neal de Hane Seagrave

Sir Henry Seagrave was the first person to hold both the land and water speed records simultaneously

Formula 1 powerboat engineering is a delicate discipline, and one small misjudgement could make the difference between victory and disaster.

"It's like driving a Formula One car across a ploughed field." The words of three-time world champion Niki Lauda after driving an F1 powerboat shortly after his third triumph in the 1980s. And that sums up the powerboat experience perfectly: a 400hp Merlin two-stroke engine propelling a 400kg catamaran at speeds of up to 150mph on a cushion of air held to the water by scant millimetres of adhesion that prevent a catastrophic failure.

One man that knows all about F1 powerboats is Jonathan Jones. The Wales-born racer lifted top honours in 1986, 1989, 1991 and finally 1998. Nowadays Jones is owner of Dragon F1 Powerboats. "When you are racing a car you are always in contact with the road," Jones explains. "When you are racing a Formula One powerboat you don't have that security. It's a six-metre catamaran that runs on a cushion of air. It looks like an aircraft because you are totally enclosed in a cockpit. You are strapped into a cocoon with a five-point harness, crashboxes either side in case of an accident and a life-support system in case it turns over.

"With a powerboat you are running on a cushion of air with probably only the last 5cm of the boat actually making contact with the water."

To control the boat the driver has buttons on the steering wheel and the floor. These control hydraulic rams that move the outboard engine at the back of the boat in and out as well as up and down. The more you move the engine out the more air is trapped inside the tunnel - the area between the two sponsons - and the faster you accelerate.

Being in control

"There is a fine line between getting it right and running on a cushion of air and totally losing control," Jones explains. "You don't want a lot of contact with the water because it creates drag, but at the same time you need some contact otherwise you lose control of the boat. You are trimming the boat by moving the engine in and out and up and down as you try to get the boat to glide millimetres off the top of the water.

"Sometimes if you alter the angle by even one or two degrees it is the difference between running the boat perfectly without any drag and getting too much air under the hull causing the boat to blow over."

The engine is on a pivot system and the hydraulic rams move it in and out. "When we move the engine out at the back it lifts the front of the boat and the more air runs in the tunnel," Jones says. "The more air you get in the tunnel the more lift you get and the greater acceleration you get.

"You come out of a corner, you trim the engine out by about 15 degrees, it lifts the nose and you capture the air in the tunnel, accelerate off the corner and try to control the boat to keep as much air in the tunnel. After about 250m you start bringing the nose down by trimming the engine in, which lowers the nose and the boat levels out as you reach top speed. You approach the corner, which is a single turn buoy about half a metre wide and you are only half a metre away, at about 125mph, take the turn and exit at about 100mph. I've measured the lateral G-force at 6.5Gs, but it happens very quickly."

There is instrumentation on board but driving the boat is down to the driver and the way he feels the boat through his backside. "The driver will play with these buttons about 100 to 120 times a lap, and each lap will last 60-90 seconds depending on the circuit," Jones says. In effect this is altering the suspension by altering the angle of the boat.

Under the 'bonnet'

The powerboats have no gears or brakes. Power is via a foot throttle but without a gearbox it is a direct drive off the 400hp engine. The engine revs are limited by the ECU box, supplied by the series organisers, to just shy of 10,000rpm. In the past these engines revved up to 12,500rpm but they didn't last very long.

All boats have telemetry on board but by F1 car standards it is fairly rudimentary. It tells the engineers how the engine and boat are performing - measuring rpm, speed and exhaust temperature. "We don't use real-time telemetry, but data that is downloaded at the end of each run," Jones says.

Because the engines don't have a gearbox, different propellers are selected for different circuits to optimise power delivery. All the propellers are four blade surface propellers. "This means that when two blades are out of the water the other two are in the water," Jones explains. "The amount of cavitation on these propellers is very slight, probably only 10 per cent slip. These will push the boat on at a speed comparable to an F1 racing car.

"I took part in a TV programme about 15 years ago called 'You Bet', in which I took on a Formula One car. We went down to London's Docklands Airport. We had the car running on the runway and the powerboat in the dock alongside it. We were doing dead starts for a quarter mile and I just beat the car over three runs."

Although the acceleration is good on a powerboat, the top speed is not as high as an F1 car. "We can run upwards of 150mph, but when we are competing it's about 130mph," Jones says. "We are looking for acceleration and mid-range, rather than top speed.

"The types of circuits are similar to F1 with a long straight followed by left and right'hand corners, so you need to pick the right propeller. You can pick one for acceleration but it might lose out on top speed; you need to find that happy medium. At each race you have a choice from about a dozen propellers."

Jones continues: "These propellers are forged from advanced materials. They are extremely thin, as sharp as a razor, and they vary in pitch and diameter. Teams would buy the blanks and modify them."

Boat specifications

Aside from Jones' company, there are several boat builders around the world - DAC and BaBa in Italy, Seabold from America, Molgard from Denmark and Moore from France. The boat is carbon fibre and the total package including engine weighs 400kg. When you finish the race the boat and driver must weigh 525kg so boats often carry ballast.

As well as the weight restriction there is a minimum length - 5.2m - but the boat can be as wide as you like and incorporate any shapes. The other restriction is the safety cell - the cockpit that the driver sits in. That cell has to pass impact testing, much the same as with F1 cars. The minimum is 3,000 Newtons.

On the outside of the cell is the crash box to absorb energy in collisions. "About eight or nine years ago there were a number of accidents where one boat would hit another," Jones reports. "Because the cell is so rigid, it's made out of 15 layers of carbon fibre and about ten layers of Dinamar, it has no give so that when one boat hit another the driver absorbed all the impact himself, causing his insides to get torn apart. That led to the introduction of the crash box, an area outside the safety cell itself, which comprises of 15mm of impact foam so in the event of a collision it absorbs the energy."

Formula One powerboat racing is the pinnacle of powerboat racing. Twelve teams each with two boats compete at ten events each year. This season begins in Brazil in early June and rounds follow in Ukraine, China, Qatar and the Emirates.

Powerboat racing

The start in a powerboat race is vital. With overtaking difficult there is a premium in reaching the first buoy ahead of the opposition. It is a dead engine start off a pontoon, which is slightly angled towards the direction of travel. "Within a qualifying lap that lasts between 60 and 90 seconds, depending on the course, there is less than a second covering all the competitors," Jones adds.

"Overtaking opportunities are limited, maybe someone runs wide at a corner and you can duck inside them, or being braver than the other guy if you are running into a head wind and the boat is almost out of control - the guy with the biggest balls would hang that boat out for a moment longer."

Over his several decades at the pinnacle of the sport Jones has seen the evolution of the boats with safety coming more to the fore. "When I started racing the boats were pretty similar to those raced today, but they didn't have the safety cocoon that drivers sit in," Jones explains. "You were strapped in, but you didn't have a life support system and you didn't have an air-bag system.

"If another driver hit the side of you, you'd had it. If you blew the boat over, you shot 40ft in the air at 130mph and when you hit the water you ended up in hospital at the very least - that happened to me many times."

In 1986 they introduced the safety cell and the canopy, which is an integrated quick-release part of the cockpit itself. It has to have a 10mm polycarbonate screen. In the event of the boat turning over and submarining it protects the driver from the force of the water.

If the boat is involved in an accident or turns over it generally turns upside down. Within five seconds an air-bag system is deployed which consists of a large bag situated behind the cockpit. At the same time two rams at the back of the boat allow water to enter the back of the boat forcing the rear to sink, allowing the airbag to hold the cockpit above the water. This allows easy access for the rescue teams.

But even though the safety has improved, nothing diminishes the buzz from racing a powerboat. "The thrill of driving the boat across the water at high speed, the sensation of acceleration and cornering is mind blowing," Jones says.

"You are running the boat on a fine edge all the time. It's not planted to the road like a car or bike. You are riding on a cushion of air and sometimes you just hold your breath hoping you are going to make it to the next corner."

Share |

Two-stroke virtuoso: Engine tuning

Alex Hledin, leading engine builder for the F1 powerboat series talks about the black art of engine tuning.

The engines mandated for the series are Mercury Marine two-stroke engines. These are the outboard motors on top of the range commercial boats. The specifications on what engine turners can optimise are tight and carefully monitored by the Union Internationale Motonautique.

"We cannot alter the bore size by more than six or seven thousandths of an inch," Hledin explains. "We cannot alter the stroke length either; bore and stroke are fixed. The other thing that is fixed is the compression ratio, so the cylinder heads are specified. These engines are also controlled by an ECU that are regulated and supplied by the organisers.

"Our main attention will be the porting, which on a two-stroke is like the camshaft on a four cycle engine. We make our own cylinder sleeves with the porting in. We also work on the air induction system and the reduction of friction. There we are talking about slippery cylinder wall materials and thinner piston rings.

"We have special connecting rods made in Sweden. We make our own pistons, or have them made to our specification. We then maximise the tuning of the engine in terms of fuel injector volume and spray patterns and droplets size."

Taking all this into consideration the gains expected over the standard package is between 6 and 7 per cent.

One advantage is that unlike other motorsports there has been an extended period of stability in engine regulations. "Thankfully they don't change the engine specification very often," Hledin says. "We started off in the late 1970s with a two litre engine, this was then bored to 2.4 litres and then up to 2.5 - so this engine has been about for over 40 years - it is the same block that Mercury uses in their high performance outboard motors."

Hledin is only half jesting when he compares his job to the black arts. "A two-cycle engine is very tricky as you don't have camshafts that can be easily changed," he says. "There are a lot of permutations and combinations that need to come together to make a difference.

"It is still a bit of a black art as there is nothing like the engine simulation software available compared to a four-cycle engine. You can almost design a four-cycle engine with a design programme. We run the engines on a dyno - last week it was four days."

Much like the engine, the fuel is standard - 100 Octane low-lead AvGas, which is available around the world so wherever the series races, the fuel is the same. Unlike F1 cars the boats are not fuel limited so there is no need to detune the engine to conserve fuel.

Death or glory: Speed records

The chase to be the fastest man on water is littered with exaltation, disaster and tragedy. Few have succeeded to claim the fame, but many have tried and failed. The chronicles record the names of those such as Sir Henry Seagrave, John Cobb, Mario Verga, Lee Taylor, Craig Arfons and Donald Campbell - who paid the ultimate price for their undertakings.

It has been 35 years since Australian Ken Warby in his Spirit of Australia shattered both the Anglo-American stranglehold on the water speed record along with the coveted 300mph barrier.

Donald Campbell set the record for Britain with a run of 276.33mph on Lake Dumbleyung in December 1964. As his record came under pressure from American Lee Taylor he attempted to improve it in Bluebird K7 in 1967 but died when he lost control on the second run.

The sight of K777 running at Coniston Power Boats Records Week in November 2011 would have sent a shiver down the spines of spectators of a certain age. The jet hydroplane, built by Helical Technology of Lytham, is a replica of the Bluebird K7.

The design came from Ben Morris and construction on the all-aluminium hull commenced in 2005. There were several differences to the original, however, including the now mandatory safety cell. The obvious choice to power the boat was an Orpheus jet engine, as used in Bluebird.

Forming of the canopy was problematic until an aircraft canopy manufacturer stepped in to assist. When it came to racing the boat, experienced hydroplane driver Jim Noone stepped up to the mark. The only person to receive the prestigious Platinum Star Award for driving hydroplanes over 150mph, Noone was an ideal choice.

Engine trials were undertaken in October 2011 and the craft was floated in the estuary for trim tests. Crafts of this type are designed to start their run low in the water and rise onto three small points, one under each front sponson and one under the transom at the rear. However, to run successfully the boat needs to be well balanced and the water calm.

Bluebird itself had early problems with balance. In initial runs at Ullswater in 1955 it took several months before she was able to hydroplane. Later at Lake Mead, Nevada, she became swamped and sunk.

By contrast K777 had 30 minutes to get it right. When throttle was applied water was thrown up into the air intakes which slowed the boat. There was insufficient time to make adjustment and when K777 ran again, water overwhelmed her and her transom slipped beneath the water. However, as K777 had greater floatation than the Bluebird she stayed on the surface.

Frantic overnight work readied the boat for a run the following day but again the attempt was thwarted, this time by the weather. There are other challengers - America Challenge, Aussie Spirit and Rush WSR, but the day may come when K777 joins the ranks of record holders.

Restoration project: Bluebird reborn

Bill Smith is team leader of the Bluebird Project, a restoration team who lifted Donald Campbell's Bluebird K7 powerboat from Coniston Waters in 2006. The team of volunteers are restoring the wreck, which held the world speed record seven times.

How did the project begin?

The rebuild began in 1996 when I decided to try and find the wreck personally. I thought it would be a fun project to work on.

Was there any damage to the boat during excavation?

The boat is a solid lump of metal, so it came up with no problems. The body of Campbell, which we also recovered, lay a few metres away where he'd landed after ejection.

What is involved in restoration?

Firstly we had to strip the boat down and clean it all up. Although this process wasn't difficult, it was lengthy. It involves anything from paint stripping to good old elbow grease.

How does the Bluebird differ from modern day powerboats?

The basic structure is the same as your average F1 powerboat. It's a hydroplane with a central hull and a jet engine. This is'the main difference between modern day engines and the Bluebird - its jet engine.

What are the challenges involved in this type of restoration?

Every aspect of restoration is difficult. But the main problem is sourcing materials from the 1950s. For example, we required a type of aluminium that was extremely difficult to source, so we commissioned its manufacture in California and imported it. Also, getting components to fit correctly was a challenge as originally everything was measured metrically.

When will it be finished?

We began restoration in 2006, but we have no idea when it'll be finished. Our team is made up entirely of volunteers and we are entirely self-funded, raising money for the project through donations and merchandise sales.

Do you partner with industry?

As this restoration is widely regarded as a completely unique project, everything's got to be reinvented. We do like to work with industry, in theory we ask them for help when we need it and they provide us with the materials we need.

Would you ever attempt racing it against an F1 powerboat when the project is completed?

It couldn't really be raced against a modern F1 powerboat as it's designed with only itself to compete with. It's designed to run in only a straight line and not to run round a circuit like an F1 powerboat.

Related forum discussions
forum comment To start a discussion topic about this article, please log in or register.    

Latest Issue

E&T cover image 1411

"This issue we honour a national hero, and the subject of Benedict Cumberbatch's latest film, codebreaker Alan Turing"

E&T jobs

E&T Marketplace

The essential source of engineering products and suppliers.

Subscribe

Choose the way you would like to access the latest news and developments in your field.

Subscribe to E&T