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Ray Wakefield -
leading up the record attempt is split into a number of phases, each with
its own clearly defined tasks and targets.
Richard Brown and Team Maximum Impulse are attempting to set the first
two-wheeled world land speed record with a thrust-powered vehicle. The
current record set by Dave Campos n the EasyRiders twin Harley-Davidson
engine streamliner in 1990 stands at 322.149mph, a speed which Richard has
twice exceeded with Maximum Impulse, using only sixty percent of the
available power of the bike.
Brown’s first bike, the Boost Palouste, unveiled in 1994 was a
The Boot Palouste hybrid
bike was powered by a Palouste gas turbine starter and a pair of
solid fuel rocket motors, and Richard hoped it would be capable of
speeds well in excess of 200mph. At the time, however, it could not
be officially called a ‘motorcycle’ as there were no classes for
non-wheel driven bikes on the books and thus it was a ‘thrust
powered two-wheeler’. Richard ran the Boost Palouste for the first
time at Bruntingthorpe, reaching a speed of 143mph and persuaded the
governing bodies to recognise classes for the thrust-powered
motorcycles. Richard developed the Boost Palouste over the nest
three years; eventually setting a UK thrust-powered motorcycle
record with a two-way average runs over 200mph in 1996.
the experience gained with the Boost Palouste, Maximum Impulse,
powered by three hybrid rocket motors and capable of a top speed of
over 500mph was designed and constructed. After initial trials on
Pendine Sands in South
in October 1997, on 15th
at Elvington in Yorkshire,
Richard set a new British Record for thrust powered motorcycles at a
speed of 216.55mph with a peak of speed of 264mph, thus becoming the
fastest man on two wheels in Britain.
September 1999, Richard and his team travelled to the famous Bonneville
Salt Flats in Utah to make an attempt on the World Record Even though he
only made a total of seven runs, the last two runs were made at speeds in
excess of the existing record, but due to technical difficulties meant
that the required return run could not be made on either occasion. The
seventh and fastest run was made at a speed of 330.639mph for the mile and
332.877mph. Unfortunately the team’s time on the salt ran out before
further runs could be made.
Maximum Impulse is two wheeled rocket
propelled land bound ‘missile’ capable of re-writing the motorcycle
speed record books.
a design peak speed of over 500mph; Richard’s latest machine owes more
to the work of aerodynamicists and to the space-race than the British
motorcycle industry. Material and engineering supplies from across Britain have supported the
construction of the vehicle as a showcase for their high technology and
Following an intense design period with co-designer Andy Scott, the build
jig was put in place and the first metal cut in October 1996 as Richard
started to create his 26foot (8m) long vehicle and in 1999 having
travelled to the USA Richard achieved a mile average speed of 531.998 kph
(330.639 mph) and a kilometre average speed of 535.599 kph (332.877 mph).
A cut away view of Maximum Impulse, the 500 kph rocket powered bike
To qualify as a motorcycle it has of course only two wheels – one that
is steerable by the rider. The wheels do not carry tyres because, for the
speeds that will be achieved, rubber pneumatic tyres are not available.
Spinning at over 9000 rpm, the wheels have special solid profiled
‘rims’ formed on to them. Suspension for each wheel will help provide
a smooth ride for Richard. The beach sand or desert playa course provides
a degree of cushioning, as well as the ‘grip’ for steering changes.
The rider lies back in a reclined position, strapped in to and surrounded
by a safety ‘capsule’, formed within the cockpit with a solid
roll-over cage above his head and body. A front bulkhead protects the
rider from the rocket propellant tank, which is mounted in to the fully
triangulated spaceframe chassis. Behind the rear cockpit bulkhead are
mounted various control valves and regulators. These are actuated by the
rider to send the oxidant to the catalyst packs and combustion chambers of
Aft of the rear wheel are the three hybrid rockets combining an HTP liquid
mono propellant element with a solid propellant to produce high energy
intense combustion stacked one above the other which when fired in
sequence will push Maximum Impluse to the record speed.
Slowing down at the end of a run is by drag parachute released by the
rider after the shutdown sequence and a purge of the rocket engines has
taken place. Once the vehicle has slowed, a rear wheel brake is used to
slow the bike to complete halt.
As riders of any bicycle know, once at rest you need to put your feet down
to maintain the bike upright. In a vehicle of this type this cannot be
done so retractable stabilisers which will keep the bike in the upright
position after each run are used.
Aerodynamics and the need to limit frontal area have dictated the shape of
Maximum Impulse. Dave Watson, the team’s aerodynamics specialist has
worked in Formula 1 and currently works on high speed Champ Cars in the USA. The final body shape was
perfected in the full size wind tunnel of MIRA-the Motor Industry Research
Association, and has been the subject of a high technology Computational
Fluid Dynamics (CFD) study. The body is constructed from hand shaped
aluminium with a moulded carbon fibre tail section.