Few people remember it, but there was also a sea Ferrari that matched the success of its racing cars. Today it is one of the most coveted objects in the world, collectors go crazy for this precious boat with the symbol of the prancing horse, now owned by a private investor who has bought it at an auction for a million and a half pounds.
This cult object is called Ferrari Arno XI Hydroplane and still holds the record, set in 1953, of the fastest boat weighing up to 800 kg set on Lake D’Iseo at a speed of 150.2 miles (242.708 kilometers per hour). The engine installed is that of the Ferrari 375 Grand Prix which won the 1951 World Championship, a 4,500 cc 12-cylinder with two compressors for a power of 600 horsepower.
Preparations began when Achille Castoldi, engineer and motorboat champion, in 1952, went to Maranello to Ferrari’s headquarters with his two closest friends, the famous champions Alberto Ascari and Luigi Villoresi, to order a V-12 Formula 1 engine.
The blessing of the Commendatore, Enzo Ferrari, was practically assured because Castoldi had managed to save a certain number of Alfetta 158 racing cars (at the time Ferrari worked for Alfa Romeo) during the war, keeping them hidden from the German occupying forces in his factory in Abbiategrasso, near Milan.
The engine chosen was the Tipo 375 V-12 designed by Aurelio Lampredi, the same unit that had powered and won the first World Championship in Ferrari with Froilan Gonzalez in 1951 and helped Ascari win the drivers’ thiolo with Ferrari in the World Championship in 1952. He originally developed about 385 hp with 12:1 compression and a double magnet ignition system, driving a two-bladed propeller through a reduction gear up to 10,000 rpm of the propeller.
Castoldi’s boat, nicknamed ‘Arno XI’, was built on a three-point seaplane project by the Timossi shipyard on Lake Como. A beautiful example of form and function in equal parts, the seaplane characterized by a solid frame structure in wood combined with marine plywood with a mahogany veneer, a separate frame for the secondary metal frame to cope with the enormous power and coverage of the engine and the outside of the cockpit properly finished in Rosso Corsa. Castoldi’s record attempt had a competitor, Mario Verga, supported by Alfa Romeo, Ferrari’s bitter rival. Verga set the record with a top speed of 226.50 km / h (140.74).
But Castoldi doesn’t give up, he wants the record. With the official support of Ferrari, including Stefano Meazza, Scuderia Ferrari’s chief engineer, he modified the already powerful Ferrari V-12 engine developed to run on methanol, thus allowing much higher engine compression in combination with two compressors and two carburetors. The power was over 600 hp, which represented a power increase of about 200 hp compared to the original specification!
Castoldi made his record attempt on Lake Iseo on the morning of October 15, 1953, with the participation of Alberto Ascari and Luigi Villoresi. He achieved his goal with “Arno XI”, surpassing the speed record in the 800 kg class with an average two-way speed in the kilometer of navigation of 241,708 km / h (150.19 mph). Later that day, Castoldi achieved a new record in the 24 nautical mile event, reaching an average speed of 164.70 km / h (102.34 miles per hour).
His victorious ‘Arno XI’ was put into storage for a few years before its acquisition in 1958 by engineer and gentleman-driver Nando Dell’Orto, who ran it in the circuit championships. With Dell’Orto, the silhouette of ‘Arno XI’ has been continuously updated by Carrozzeria Boneschi of Milan with an even more powerful engine, fairing with “shark nose” grip and a large vertical stabilization fin at the rear. So modified, “Arno XI” achieved several fastest lap records and three titles, including the European Championship in 1963. Nando Dell’Orto retired from the competition in 1968, leaving “Arno XI” in the huge warehouse of his paper production plant located in the Milan suburbs.
Now it is jealously guarded by the collector who bought it for a million and a half pounds.