NSB El 18

for CargoNet During the early 1990s, NSB was in need of new electric haulage for their passenger trains, as both classes El 11 and El 13 were in need of replacement. El 17, the latest purchase, had proved unreliable, and NSB wanted to remove them from mainline service. In 1993, Re 460 and EuroSprinter locomotives were tested in Norway, with the Re 460 being tested from 28 August through 8 October. NSB was satisfied with both units, and stated that it would be possible to increase the train weight on the intercity services from . During the first half of 1994, NSB leased two Re 460s to have sufficient locomotives for operation during the 1994 Winter Olympics. When the deadline for bids for the units was reached on 8 May 1994, five bids had been received. GEC Alsthom offered a modification of the French SNCF Class BB 36000 and AEG offered a variation of the German prototype 12X. Siemens offered two models, the EuroSprinter and an adaptation of the Austrian ÖBB Class 1014. The final offer was from Asea Brown Boveri (ABB), and Swiss Locomotive & Machine Works (which by delivery would be sold to become Adtranz) for "Lok 2000", a modification of the Swiss Re 460. Another important aspect for NSB was that as much of the production as possible take place in Norway. During 1997, there were five incidents where NSB's Nordic Mobile Telephone equipment interfered with the locomotive's electronics, causing the emergency brakes to activate. This caused a temporary halt until the motorman had unlocked the brakes. The problem was fixed by moving NSB's mobile transmitters. The units were taken into use on the Bergen Line from 5 January 1997. Later they entered into use on the Dovre and Sørland Lines, and then on regional trains around Oslo, such as the Vestfold Line. In August 1998, NSB stated that El 18 used more power than some of the substation transformers along the line could handle, particularly along the Vestfold Line. Part of the problem was caused by a mechanism in the locomotives whereby the motor was turned off if the wheels spin. The result was that the full power output of the El 18 along parts of the railway network could not be utilized. Three have been operated by Go-Ahead Norge since December 2019. ==Specifications==

The locomotives have a maximum power output of , and are capable of a continual power output of . This gives a maximum speed of and a tractive effort of . The locomotive is fed power from the pantograph. This is then converted to direct current before being converted to three-phase electricity through one of three gate turn-off thyristors. Each bogie has three rectifiers, each connected to a transformer that is again connected to two inverters. The motors are three-phase asynchronous motors located in the bogie frame and equipped with regenerative brakes. There is also an auxiliary three-phase power supply which powers the compressor, pumps, ventilators and other auxiliary equipment, operated by four separate inverters. The controller is a 16-bit microprocessor that communicates using optical fibre cables. The rectifier, auxiliary rectifiers, controllers and the error and diagnostic system is of the same type as used on the NSB Class 70 multiple units. The El 18 has a Knorr HSM mechanical braking system, but unlike the Swiss versions does not have a rail brake. The design of the locomotive was by the Italian company Pininfarina. The machine room is designed with a center aisle, the driver's cabs have pressurization applied to avoid air pressure dropping when running through tunnels, and the cabs are equipped with air conditioning. ==References==