NSB Di 8

NSB Di 8
CargoNet Di 8.704 at Nässjö Central Station, Sweden
Type and origin Power type Diesel-electric Builder Siemens Schienenfahrzeugtechnik Build date 1996–1997 Total produced 20
Specifications Configuration: ​  • UIC Bo'Bo' Gauge 1,435 mm (4 ft 8 1⁄2 in) standard gauge Length 17.4 m (57 ft 1 in) Width 3.0 m (9 ft 10 in) Height 4.385 m (14 ft 4.6 in) Loco weight 82 t (81 long tons; 90 short tons) Fuel capacity 3,500 L (770 imp gal; 920 US gal) Prime mover CAT 3516 DITA
Performance figures Maximum speed 120 km/h (75 mph) Power output 1,570 kW (2,110 hp)
Career Operators Norwegian State Railways 1997–2002 CargoNet 2002– GB Railfreight 2011– Numbers 8.701–720

The NSB Di 8 is a class of diesel-electric locomotives built by Maschinenbau Kiel (MaK), while it was part of Siemens Schienenfahrzeugtechnik, for the Norwegian State Railways (NSB). The locomotives are equipped with a Caterpillar 3516 DI-TA prime mover, which provides a power output of 1,570 kilowatts (2,110 hp) and a starting tractive effort of 270 kilonewtons (61,000 lb_f).

Twenty locomotives were delivered in 1996, largely based on MaK's previous production series, the Dutch NS Class 6400 and German DE 1002, although receiving some upgrades to the specifications. NSB took delivery of the class to replace the aging Di 3, and the units have been used on freight trains on un-electrified lines, including the Nordland Line and the Røros Line. They were transferred to CargoNet in 2002, when NSB's cargo division was demerged. Ten units were sold to GB Railfreight in 2011 and are used at the Teesside Steelworks in Redcar, United Kingdom.

During the late 1980s, the Norwegian State Railways sought a new locomotive type to replace its aging fleet of Di 3 diesel-electric locomotives, which made up the back-bone of the dieselized operations. The new locomotives were planned for use as freight and passenger trains on the Nordland Line, and to a lesser extent on the Røros Line. In 1980, NSB had taken delivery of five Di 4 from Henschel. Originally there were plans to order additional Di 4 units, but this was discarded and instead a new class was pursued, as NSB wanted similar, but slightly more modern, locomotives.

A MaK-built DB Class 240 locomotive was test-run in Norway during 1990. On 23 November 1992, NSB's board decided to order ten similar units, later expanded to twelve, which would primarily be used in passenger trains. During the procurement process, NSB started to pursue the smaller locomotives for freight trains, and turned to MaK to investigate their smaller locomotives. NSB's need for hauling power was dire enough that the company leased two locomotives of two classes of diesel-electric locomotives, the SJ T44 from the Swedish State Railways and the MaK-built NS 6400 from Nederlandse Spoorwegen.