Austin Marine Engines
In 1910 Herbert Austin
decided to build a Marine engine that at the time was very
advanced. It produce 300bhp and was installed in a speed-boat
called "Irene I" which was named after his eldest daughter who had
married Colonel Waite. The all aluminium twin ohv engine had twin
magneto, twin carburettor and desmodronic valves. A year later in a
revised boat now called "Irene II" and a new engine which produced
380 bhp. With this boat it successfully became the holder of the
world water speed record on Southampton Water. (If anybody knows the
actual speed, please contact me)
Irene at full
throttle
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Harmsworth Trophy
In 1903 the proprietor of
the Daily Mail, Sir Alfred Harmsworth commissioned this bronze
trophy to encourage the development of power boat racing. The
contest would be between nations, and be run annually. Any nation
could enter, but the boats had to be designed and built entirely by
residents of that country, along with materials and engines etc.
The first race ran took place on the 11th July 1903, which was won
by S F Edge's in Napier Minor.
A wealthy Canadian financier, Sir Edgar Mackay, had three boats
built to enter for the "The Harmsworth Trophy" bearing the name
Maple Leaf I, II and III, but each boat had failed to come up to
expectations.
Maple Leaf III had two huge Vl2 engines of about 350hp each,
designed by the New Orleans Company but only constructed one, the
second being constructed to the same design by Dixon Bros &
Hutchinson Limited of Southampton. Mackay Edgar was not satisfied
with Maple Leaf III's performance, so he decided to have the next
boat, Maple Leaf IV constructed by S. E. Saunders of Cowes.
Saunders had been involved in designing and building boats for many
years, but they realised that though Maple Leaf III had powerful
engines most of the power was absorbed by the friction of the
water. It appears that various patents had been taken out whereby
the underside of the boat varied in shape. Maple Leaf IV had an
aquaplane hull having five steps of varying cross section, and at
maximum speed would lift onto the third step.
Maple Leaf
IV
Left to Right, Mr J W
Kinchin - Lord Austin - Mr Stapleton, Engineer and
Coxwain.
Mackay Edgar approached
Austin were to improve the engines, and Mr J W Kinchin was given
the task of improving the design of the American engines, working
at Longbridge on their development. First he had the engines
stripped down, and all components measured to see if they were
correct to the drawings.
But one of the main problems was that the engines ran too hot,
thereby causing various other components to fail. It soon became
obvious, that if it was going to be competitive it would be
necessary to implement a major redesign of the engine. New cast
iron cylinders were designed that had much larger coolant passages.
also the pistons were strengthened and lightened, along with
changes to the valve train and the valves themselves.The side
exhaust valves and overhead inlets were operated by push-rods from
a single camshaft in the 'V' of the aluminium crankcase. This was
driven by twin chains from the crankshaft, which ran on seven
bearings. Each bank had its own magneto and carburettor.
To improve reliability a new pressure-fed oil system was designed
that could supply all the bearings, etc, with a constant supply of
oil at 20lbs per sq inch. Each block of six cylinders would have
its own inlet manifold and exhaust system.
To start these large engines, a small ABC flat-twin engine was
used.
By fitting new double-helical reducing gearboxes of Citroen design,
the forward weight of the boat was reduced by a considerable
amount.
Front
End
Rear End
After carrying out various tests and modifications on the engines,
it was now producing 380hp. But for the boat to stand any chance of
regaining the record for England, it would have to reliably exceed
40 knots. With the testing at Longbridge over, it was now time to
carry out testing on Southampton Water. It did three runs with the
current and three against the current, averaging 45 knots on the
Thorneycroft mile. With some more adjustments it finished the tests
having now got the average speed up to 52 knots. Kinchin was very
happy with the trials, and so he should be, because this was the
first boat in the world to average over 50 knots.
It was now time to take the boat over to America, to aim at
regaining the British international trophy from the Americans. The
race took place in Huntington Bay, over a 30 mile course. The first
race went to the American boat Reliance II, so it was must
important that Maple Leaf IV with Tom Sopwith at the helm, wins the
second race. All went well, with the Englishman crossing the line
first. Now everything hinged on the last race, with Sopwith's
seamanship and the boats constant performance in its favour. Maple
Leaf IV crossed the line first in a time of 48 minutes 16 seconds,
which was the fastest ever recorded at an average speed of
43.57mph. Second place went to the American Reliance III, coming in
over three minutes later. Reliance II which won the first race
failed to finish.
Maple Leaf
IV
Boat
information
Overall Length 40ft, - Beam
8' 5'', - Draught 3' 0", - Displacement 5.25 tons, - Engine
800hp,
Propeller Diameter 25", - Propeller speed
1,100rpm