Timossi-Ferrari 'Arno XI' Racing Hydroplane

The Arno XI is a hydroplane inspired by Achille Castoldi in the early 1950s and built by Timossi Azzano’s Cantieri boatyard located on Lake Como. Castoldi wanted to establish a world water speed record so he persuaded then Ferrari racing drivers Alberto Ascari and Luigi Villoresi to influence Enzo Ferrari to supply him with a 4.5-litre, V12 Ferrari engine; the same engine that gave Ferrari his first Grand Prix victory with the Ferrari 375 F1 at Silverstone Circuit in 1951.^[1][2]

Engine modifications

Castoldi managed to further increase horse power by attaching two superchargers. The result was a 502 bhp speedboat, which he used to hit a 150.19 mph top speed in October 1953 on Lake Iseo. That remains the world speed record for an 800 kg boat till today.^[3][4]

Specifications

• Timossi di Azzano three-point racing hydroplane hull.
• Length: 6,200 mm (245”).
• Beam: 2,470 mm (97.24")
• Engine: 600+ bhp, 4,493.73 cc Ferrari Tipo 375 F1 V-12 engine with twin superchargers and twin four-choke carburetors.

Today

Arno XI was later sold and raced in numerous competitions, finally retiring in 1960. It has since been restored and is expected to go for up for sale by RM Auctions for up to €1.5m.^[5]

References