FS Class E.331 was a class of

three-phase Three-phase electric power (abbreviated 3φ) is a common type of alternating current used in electricity generation, transmission, and distribution. It is a type of polyphase system employing three wires (or four including an optional neutral r ...

electric locomotive An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or on-board energy storage such as a battery or a supercapacitor. Locomotives with on-board fuelled prime movers, such as diesel engines or ga ...

s of the Italian State Railways. Eighteen of these 2′C2′ locomotives were built between 1914 and 1919 by

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and

Brown-Boveri Brown, Boveri & Cie. (Brown, Boveri & Company; BBC) was a Swiss group of electrical engineering companies. It was founded in Zürich, in 1891 by Charles Eugene Lancelot Brown and Walter Boveri who worked at the Maschinenfabrik Oerlikon. In 1970 ...

Overview

Eighteen of these locomotives were built by

, with electrical parts by

, between 1914 and 1919. The class had the same pole-changing system as the E.330 which allowed an increase in the number of economic speeds to four. Until a few years earlier, only two speeds could be obtained with the arrangement of

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or parallel

traction motor A traction motor is an electric motor used for propulsion of a vehicle, such as locomotives, electric or hydrogen vehicles, elevators or electric multiple unit. Traction motors are used in electrically powered rail vehicles ( electric multipl ...

connections. In the E.331, a further two economic speeds could be obtained by changing the number of poles on the traction motors. One of the limitations of the machine, and the source of numerous failures, was the type of rotary switch used to vary the number of poles. Current was picked up from the two-wire

overhead line An overhead line or overhead wire is an electrical cable that is used to transmit electrical energy to electric locomotives, trolleybuses or trams. It is known variously as: * Overhead catenary * Overhead contact system (OCS) * Overhead equipm ...

by two pantographs, both continuously in use. The locomotive was built on a rigid frame, with three coupled axles driven by two

jackshaft A jackshaft, also called a ''countershaft'', is a common mechanical design component used to transfer or synchronize rotational force in a machine. A jackshaft is often just a short stub with supporting bearings on the ends and two pulleys, gear ...

s connected to the motors by inclined

connecting rod A connecting rod, also called a 'con rod', is the part of a piston engine which connects the piston to the crankshaft. Together with the crank, the connecting rod converts the reciprocating motion of the piston into the rotation of the cranksha ...

s. The front and rear

bogie A bogie ( ) (in some senses called a truck in North American English) is a chassis or framework that carries a wheelset, attached to a vehicle—a modular subassembly of wheels and axles. Bogies take various forms in various modes of tr ...

s had smaller diameter wheels, as was usual for the locomotives of the time.

Service

Class E.331 locomotives were used between

Turin Turin ( , Piedmontese: ; it, Torino ) is a city and an important business and cultural centre in Northern Italy. It is the capital city of Piedmont and of the Metropolitan City of Turin, and was the first Italian capital from 1861 to 1865. Th ...

and Bussoleno, on the Frejus line. The 2′C2′ machines, with maximum speed and power of about , were at their ease, especially on the flat or on gentle gradients.

Overview

Service

References

Further reading