The Fastest Ferrari on Water
While racing has allowed car manufacturers to demonstrate their engineering skill and provided a way for a long-line of sportsmen to get their thrills for over a hundred years, a similar technological struggle has taken place on water where endurance racing and a quest for speed records have been pursued. As car engines became more powerful and finely tuned during the 1930s, those same power-units became attractive to designers of competition boats. With competitive marine racing, like its land-based cousin, fuelled by publicity and advertising, top manufacturers of their day such as Maserati and Alfa Romeo were keen to jump on board. Both teamed up with Italian boat racers in a quest for more speed and national pride, supplying retired race engines.
One such wealthy privateer was Achille Castoldi. In 1940 he set the world speed record of 130.52 km/h (81.10 mph) in the 400 kg class with his boat Arno. Arno was powered by an Alfa Romeo type 158 engine, the same engine design that would line up at Silverstone ten years later as the remnants of motorsport recovered from the Second World War to establish the Formula One World Championship. Further Arnos were built in a quest for more speed, mostly powered by Alfa Romeo engines plus the occasional Maserati. However, at the end of 1951, Alfa withdrew from Formula One with the Italian government refusing to fund the development of a new car – by this time the 158 was a fourteen-year old design. Despite having powered both Drivers’ Champions, Alfa bowed out of Formula One and the result seemed to have a knock-on effect on their support of boat racing as they opted to focus solely on Castoldi’s closest rival, Mario Verga.
By now, Castoldi was focussed on speed records instead of circuit racing and in 1953 he commissioned an 800 kg-class hydroplane hull to be built by Cantieri Timossi, a designer based on Lake Como, near Milan. It featured a solid wood frame covered with a plywood skin and a mahogany veneer. Over the hull went an aluminium fairing, rear aerodynamic stabilizer and engine cover – all painted in the traditional rosso corsa of Italian racing. Arno XI was born but in need of an engine. Castoldi turned to the new power house of Formula One – Scuderia Ferrari.
Ferrari supplied Castoldi with a 60°, V12 Grand Prix engine designed by Aurelio Lampredi for the Ferrari 375 F1. It was the same type that had powered Ferrari to their first Formula One victory in 1951, dominating the second half of the season before 2 litre regulations were adopted the following year. It short, it was the Formula One engine to have. Displacing 4493.7 cc, the engine generated some 300 bhp at 7,000 rpm and, by the time it had gone through the gear box, was able to turn the boat’s twin bladed propeller at up to 10,000 rpm.
In Pursuit of Speed
In January 1953, Castoldi piloted Arno XI to an unofficial top speed in excess of 124 mph during testing. However, Mario Verga, powered by Alfa Romeo, set a new 800 kg-class speed record of 202.26 km/h (125.68 mph) over the “flying kilometre”. A fortnight later, Verga had pushed it up to 226.50 km/h (140.74 mph).
In order to surpass Verga’s new record, Castoldi had a new engine built. The 4.5 litre Ferrari engine now sported twin superchargers and a pair of 4 barrel Weber carburettors. Moreover, the engine would now run on methanol, allowing even higher compression ratios in order to get the optimum performance out of the superchargers. The result was an increase in power to around 550-600 bhp.
In addition, Enzo Ferrari seemed keen to defeat Alfa and following his rival’s lead of providing technical support sent Stefano Meazza, the Scuderia’s chief race engineer, to help prepare the new engine. On the morning of 15th October, 1953, watched by Formula One Champion Alberto Ascari and team mate Luigi Villoresi, Castoldi smashed Verga’s record, pushing past the 150 mph barrier. On the waters of Lake Iseo in Lombardy, his average speed across his two-runs over the kilometre was 241.71 km/h (150.19 mph). Later the same day, he went on to break the “24 nautical miles” record with an average speed of 164.37 km/h (102.13 mph), a record that was to remain unbroken as the Italian Powerboat Federation later changed the categories.
With Formula One moving to a 2.5 litre formula, Formula One rapidly drifted away from being able to provide the finely developed engines eagerly sought by competitive boat racers, who turned instead to aircraft engines. Indeed, Donald Campbell was already constructing the jet-propelled Bluebird K7 which would achieve speeds far beyond the reach of of the combustion engine. Castoldi retired from racing the following year, after his new 1700 kg-class hydroplane’s engine failed catastrophically at high speed. He was one of the fortunate ones – since 1940 the fatality rate in attempting the water speed record is around 85%. His great rival, Mario Verga, wasn’t so lucky and was killed later that year when his latest boat overturned and disintegrated at an estimated speed of 190 mph while attempting the outright record.
Arno XI, meanwhile, was sold and sporting a revised engine cover and stabilising “shark” fin behind the driver (shown in the photographs), raced for many more years. Remarkably, twelve years after her record-breaking run, Arno XI recorded a second place finish in the 900 kg World Championships of 1965.