AN ATTEMPT ON THE BRITISH INTERNATIONAL TROPHY.
What may be described as the last word in modern motor boat design is embodied in the two boats to be used by Miss M. B. Carstairs, in an attempt to regain the International Trophy for Britain, held by America since 1920.
The boats to be used are Estelle I and Estelle II, and Estelle III is cimtemplated, embodying the best points of I and II.
Both craft are equipped with the same type of power unit, namely, the 900 b.h.p. Napier 12-cylinder engine used by Flight-Lieut. Webster in the Schneider Cup, and by Capt. Malcolm Campbell in his Napier Bluebird at Daytona.
The engine is unsu.percharged, and the compression is in the region of a 10 to I ratio. The cylinders are arranged in three blocks of four, radially disposed, and develop 900 b.h.p. at 3,300 revolutions.
Estelle I measures 26 ft. with a 5 ft. 6 in. beam, and is a single step boat. Direct drive is arranged for by tilting the engine, and louvres are arranged for ventilation, while part of the engine is exposed altogether as shown in the photograph. The total weight is about 2,900 lbs. The boat has been designed to attain Ioo m.p.h., and the designer is Mr. F. P. Hyde-Beadle.
Estelle II is not quite so original in appearance as her sister craft. She measures 21 ft. in overall length, with a beam of 6 ft. An interesting feature is the arrangement for an efficient shaft angle by the use of a gear-box forward of the engine allowing the propellor to run at engine speed.
Estelle II is V-stepped transversely, rather deeper than Estelle I.