Specifications
The locomotives each have four NEBB EDTM423 motors, giving a combined power output of 712 kilowatts (955 hp). The main transformer is capable of feeding each motor with 765 kilovolt-ampere (kVA), 115 kVA to heating and 40 kVA for axillary equipment. The power output is regulated with through 28 steps in the voltage regulator which is integrated with the main transformer. The locomotives have a maximum speed of 60 km/h (37 mph) and a tractive effort of 108 kilonewtons (24,000 lbf). Because of the limited roof space, only one pantograph was installed.
The limit on axle load makes the locomotives small and compact. They weigh 48 tonnes (47 long tons; 53 short tons), and the total train weight is limited to 85 tonnes (84 long tons; 94 short tons). This also gives the trains a short length of 10.2 meters (33 ft). The trains had a Bo'Bo' wheel arrangement. In addition to air brakes for the whole train, the locomotives are equipped with rheostatic brakes which is sufficiently powerful to allow for the 5.5 percent gradient. When braking, three of the motors are connected to the air-cooled resistance on the roof, while the last motor is connected to deliver magnetization current to the other three motors. The braking is regulated with 22 steps. As a backup, the units are equipped with a carborundum track brake on each side of the bogies.
Read more about this topic: NSB El 9