The NIR 101 Class is a class of diesel-electric locomotive formerly operated by Northern Ireland Railways (NIR). With the return to the working of the Enterprise service from Belfast to Dublin with coaching stock instead of augmented diesel railcar sets, NIR found itself with no suitable main line diesel locomotives. The Class 101 (DL) became the answer to the immediate problem working in conjunction with the newly acquired British Rail Mark 2 coaches. History The 101 Class of NIR consisted of three mainline diesel-electric locomotives designed for use with the Enterprise passenger services between Belfast and Dublin. The intention was to reduce the time for the 180 km (112-mile) journey to two hours. The design of the superstructure and bogies was carried out by the Hunslet Engine Company of Leeds with English Electric-AEI Traction being responsible for the traction equipment. The contract stipulated a ten-month delivery period but with Hunslet's workshops already committed, the superstructure and assembly was contracted out to (British Rail Engineering Limited's, Doncaster Works), Hunslet providing the bogies. They were of Bo-Bo wheel arrangement and fitted with CSVT Mk. II engines. The locomotives were fitted with buckeye couplers as standard and had air brake capability for operation with the Mark 2 coaches. They were visually, mechanically & electrically very similar to the KTMB class 22 (Keretapi Tanah Melayu Berhad - Malaysian Railways) locomotives built by English Electric at around the same time, however these had had a Co-Co arrangement and an uprated power unit. A small number are still operated. The press launch of the new Enterprise was held on 3 July 1970 when a special train, carrying invited guests, ran from Great Victoria Street, Belfast to Dublin with two locomotives working the train, one at each end. This was generally well received, however comments were made regarding the train "hunting" due to the second locomotive pushing from the rear. All three re-use names previously used by the Great Northern Railway Class V locomotives, as follows: Replacement Towards the end of the 1970s, although only 10 years old, the class were suffering from regular failures in service and they were displaced from the principal passenger workings by the arrival of the NIR 111 Class locomotives. The 101s were cascaded to lesser duties, such as shunting in Adelaide Yard. All three locomotives progressively withdrawn from service, the first having been stored in 1989 (103) and the last in