FS Class E.636

Locomotive class

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 groups, 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.

E.636 are very simple locomotives. Most functions of the main command circuit are accomplished through various relays and contactors. In case of failure the train driver could easily fix them to at least free the tracks; also, especially in the last years of their service, E.636s were the first locomotives that the new train drivers studied during their training courses, due to their simple working mechanics.

The locomotive is formed by two half carbodies, pivoting over the central bogie. Between them, there is a bellows, which was originally made with rubber then replaced in the 1950s by an impermeable membrane. In recent years this was further replaced by flexible plastic material. On post war units, reinforcement frames have been introduced on the chassis and under the cabs, as the first 108 units showed some mechanical weaknesses in those points; in the mid 1980s it was decided to reinforce only the chassis on pre war units (however units 026 an 065 never received these modifications). To reduce parasite motion, dampers were mounted between the carbodies: glycerine type from units 1 276 and special oil type from unit 277 onwards, although these were later eliminated in 1977 because considered useless. The first 108 units had different rheostat ventilation shafts on the roof than the rest of the units ones, although these were later replaced with the more efficient shafts used on the latter units. They also had sliding oil buckles, while following units had rolling bearing ones. Units 162 171 were equipped with French derived Athermos buckles for testing purposes, which were later removed. Sandthrowers were mounted internally into the bogie in the units 001 108; after the war they were replaced by external ones that also were natively mounted on later units.

The first 108 locomotives originally had mounted a vigilance pedal designed by FS engineer Minucciani, that required a periodic acknowledgement from the driver when the train was moving (or emergency braking would have been commanded), but after the war, due to labor union pressures, it was discontinued; however, starting from the 1970s, many (not all) units received "Ripetizione Segnali a 4 codici" system, Hasler speedometer and a modified "speed graph recorder" (Zona tachigrafica), that also recorded the codes received from the RS.

E.636.385 was part of the "PV Train" project and received photovoltaic cells used to recharge the 24 V batteries. Due to this, it has been inserted in the asset of Italian historical units;
E.636.082 has been used for testing in 1965 of rheostatic braking (the same system was later adopted on FS Class E.444); a second, smaller lever was mounted on the top of the traction lever, and was used to control the braking rheostat. This units also mounted more and bigger vents on its sides. At this time, it has been stripped of many internal components, and is not able to run. E.636.284 is maybe the most famous unit of the group. The unit was involved in an accident, where the driving cabin was damaged. FS decided to recover the unit, and also decided to experiment a new type of driving cabin, similar to the ones used on FS Class E.656. The unit is nicknamed "Camilla", originating from which is supposed to be the girlfriend's name of a worker employed in the rebuilding works, who wrote it with chalk near one of the couplers of the locomotive. This unit is also historical. In 1951 units 044 and 089 received the 92 250 type motors, used on FS Class E.424, and the gear ratio was also changed to 20/65, for a maximum speed allowed of (max power instead of ). The results of this experiment had proven successful, as these locomotives had the same performances as FS Class E.428 (gear ratio 31/101), but with less weight and power; however they were later brought back to their original status. Units from 271 to 275 were built with different bogies than the standard ones (similar to the ones used on the FS Class E.646 prototypes), 32RT 200 motors, 5 shunt levels and a gear ratio of 24/74 (max speed ). These units were later made identical to standard units. During the 1960s 1970s Ansaldo Breda built a locomotive derived from E.636 for use in Yugoslavia, classified JŽ 362.