FS Class E.636

FS class E.636

E.636.002 in its original livery, property of FerAlp Team museum in Bussoleno

Type and origin Power type Electric Builder Breda, OM CGE, OM Reggiane, Marelli, SNOS Savigliano, FIAT, TIBB, OF Pistoiesi, Ansaldo Build date 1940–1962

Specifications Configuration: ​  • UIC Bo-Bo-Bo Gauge 1,435 mm (4 ft 8 1⁄2 in) standard gauge Wheel diameter 1.250 m (49.21 in) Wheelbase 5.200 m (17 ft 3⁄4 in) between bogie pivots 3.150 m (124.02 in) between axles of each bogie Length 18.250 m (59 ft 10 1⁄2 in) Width 3.000 m (9 ft 10 1⁄8 in) Height 3.380 m (11 ft 1 1⁄8 in) Loco weight 101 short tons (90 long tons; 92 t) Electric system(s) 3,000 V DC Catenary Current source Pantograph Traction motors DC series Transmission 21/65, 20/65, 28/65 and 24/74 gear ratios

Performance figures Maximum speed 120 km/h (75 mph) Power output 2,100 kW (2,800 hp)

Career Operators FS Trenitalia Number in class 469 First run 1940 Disposition decommissioned in 2006

The FS E.636 is a class of Italian articulated electric locomotives. They were introduced in the course of the 1940s until the 1960s, and have been decommissioned since 2006. They have been one of the most numerous Italian locomotive group, and have been widely employed during their long career, hauling every type of train, ranging from freight to long range passenger services. Their introduction also saw the employment of some revolutionary (for the time) design concepts, such as the articulated carbody and the three bogies scheme.

The E.636 was designed to overcome the problems showed in the 1930s by both the E.626 multi-purpose and E.326 high-speed locomotives, in order to better handle the increasing railway traffic in Italy.

The E.636 was the first Italian locomotive adopting the Bo-Bo-Bo configuration with chassis divided into two articulated parts pivoting on the central bogie, which is very well suited for the often tortuous lines of Italy and that would have been later repeated on the E.645/646 and [[FS Class E. 656|E.656]] classes. The presence of a great number of wheels was considered important due to the presence of a number of high-slope lines in the Italian railroad network as it increases the adhesion limit, meaning that the locomotive is less prone to wheel slips. The new engines weighted approximately 101 short tons (90 long tons; 92 t). Engines were initially the same as E.626. The 32R used a 3 kV catenary but this was soon shown to be inadequate and so were updated and provided with a new hollow axle transmission system. Mainly two different gear ratios were installed: 21/65 for sloping lines or heavy freight trains (maximum speed of 95 km/h (59 mph), elevated later to 110 km/h), and the longer 28/65, with a maximum speed of 120 km/h (75 mph), suited for passenger services.

The locomotive was built in three different series:

The first unit entered service in May 1940. Six locomotives were destroyed during World War II. After the war the total number of locomotives was brought to 469, also thanks to the support from the Marshall Plan, and making it one of the most numerous groups of Italian locomotives. All the units were painted with an auburn livery; this was changed in the 1990s to a white one with green stripes for most trains (XMPR livery).