New Zealand DSC class locomotive

New Zealand DSC class
DSC class locomotive 2693 at Dunedin
Type and origin Power type Diesel-electric Builder British Thomson-Houston (18), NZR Hillside Workshops and Addington Workshops (52) Build date 1959–1967
Specifications Configuration: ​  • UIC Bo-Bo Gauge 1,067 mm (3 ft 6 in) Length 11.66 m (38 ft 3 in) Width 2.54 m (8 ft 4 in) Height 3.5 m (11 ft 6 in) Loco weight 41.1 tonnes (40.5 long tons; 45.3 short tons) Prime mover BTH: Rolls-Royce C6SFL, 2 off; later: Rolls-Royce C6TFL, 2 off. NZR: Leyland UE902, 2 off; later: Cummins NT855, 2 off.
Performance figures Maximum speed 64 km/h (40 mph) Power output 315 kW (422 hp) Tractive effort 46 kN (10,300 lbf)
Career Operators New Zealand Railways, Tranz Rail, Toll Rail, KiwiRail Number in class 70 Numbers Early numbers: 400–469 TMS numbers: 2000–2759 Locale All of New Zealand First run 1958 Retired 1989 – Disposition 32 in service; 29 scrapped, 4 stored out of service; 2 preserved, 3 are owned by industrial uses.

The New Zealand DSC class is a heavy shunting locomotive used throughout New Zealand. The class was built in seven batches, the first 18 locomotives being built by British Thomson-Houston of the United Kingdom, with the remainder being built by New Zealand Railways.

The class is widely used in both the North and South Islands of New Zealand, mainly for heavy yard shunting, although some members of the class have been used for local mainline shunting services. All members of the class are now fitted with shunters refuges, and most are fitted with remote control capabilities.

Design and entry into service

In the late 1950s, NZR needed a suitable heavy shunting locomotive that produced more power than the existing D^S and D^SA class locomotives and would be suitable for replacing the B^B, C, and W^F class steam locomotives. In 1959, an order was placed with British Thompson-Houston in association with the Clayton Equipment Company for eighteen centre-cab shunting engines with a horsepower output of around 420 hp.

The new locomotives, allocated road numbers D^SC 400-417, entered service in 1959-60 and were allocated to Auckland and Frankton Junction (Hamilton). For a time in 1962, D^SC 402 was dispatched to Picton to shunt the NZR road/rail ferry MV Aramoana until newly constructed Addington D^SC 418 arrived to take over, allowing 402 to return north.

The BTH locomotives were powered by two Rolls-Royce C6SFL 210 hp diesel engines connected to BTH generators, which were in turn coupled to four BTH traction motors, one to each axle. They were not entirely without trouble, though, with issues arising with the airbrakes and spare parts for the diesel engines among others. However, once this was resolved, the class settled down to work reliably in their intended role.

Two further orders were placed with the NZR Addington and Hillside Workshops in the 1960s, with production running from 1962 to 1967. The NZR-built locomotives were different in that they were powered by two Leyland UE902 diesel engines producing 210 hp, and had electrical equipment built by Associated Electrical Industries Ltd (AEI), which had purchased BTH earlier. Again there were various troubles, this time more to do with the mechanical components and compatibility on later batches.

Re-engining

In the late 1970s, NZ Rail decided to undertake a re-engining programme for the D^SC class. Due to design differences, it would not be possible to use the same type of diesel engine across all locomotives, and so two different types were selected:

• All BTH locomotives would be repowered with the Rolls-Royce C6TFL diesel engine.
• All NZR locomotives would be repowered with the Cummins NT855 diesel engine.

The process was spread out from the late 1970s into the early 1980s. As part of this, some locomotives were repainted in the International Orange livery but with their pre-TMS numbers instead of the later TMS numbers. As a result of this, the locomotives were equipped with new radiator header tanks which were mounted behind the radiator on top of the engine hoods in a 'north-south' alignment. Later the tanks were relocated to an 'east-west' alignment.

Fitting shunter's refuges

In 1989, DSC 2406 was trialled as the first shunting locomotive to be fitted with shunter's refuges at either end of the locomotive. New recessed steps were fitted at either end of the locomotive frames with a vertical hand-rail on the running-board proper. The locomotive's engine hoods were not shortened at the time.

This modification was successful, but it was noted that the engine hoods were a potential constraint. All further DSC class locomotives equipped with the refuges had their engine hoods shortened by 500mm, necessitating the relocation of the radiator header tanks to their present 'east-west' alignment.

This modification was subsequently made to all DSG, DSJ, and DH class locomotives as well as DAR 517. None of the BTH-built DSC class locomotives were fitted with these refuges and several NZR-built examples did not receive them either, due to withdrawal before they could be fitted or by dint of being used for other purposes.

Withdrawal and preservation

As part of the program of the New Zealand Railways Corporation to rationalise the locomotive fleet in the late 1980s, a number of the older mainly British Thomson-Houston built locomotives were scrapped. Sixteen were scrapped at Otahuhu Workshops and one (DSC 2000, originally D^SC 400) was scrapped at Hutt Workshops in 1990. The eighteenth locomotive, DSC 2067 (D^SC 406) was withdrawn in 1989. However, it was given a reprieve when it was sold to New Zealand Milk Products (later subsumed into Fonterra) to shunt their Whareroa milk factory. In 2007 the locomotive was sold to the Alliance Group Ltd to shunt at their Pukeuri freezing works on the outskirts of Oamaru.

Various other NZR-built locomotives were scrapped as being surplus to requirements or due to accident or fire damage. Two more have since been sold into industrial service; DSC 2421 was sold in 2002 to the Alliance Group to shunt at their Lorneville freezing works near Invercargill, while DSC 2257 was sold to Ravensdown Fertiliser in 2007 and is stored at their New Plymouth depot.

Two class members have been sold into preservation, both of which are NZR-built locomotives. DSC 2584 (D^SC 453) was sold to the Waitara Railway Preservation Society for use on their passenger trains between Waitara and Lepperton. The other, DSC 2759 (D^SC 469) was sold to Ian Welch for the Mainline Steam Heritage Trust and is used as the depot shunting locomotive at Plimmerton along with Bagnall TR 534.

Class register

TMS No.	Original No.	Builder	Introduced	Withdrawn	Current Livery	Status	Allocated to	Notes
DSC 2000	400	BTH	May 1959	October 1989	International Orange	Scrapped
DSC 2013	401	BTH	June 1959	September 1989	International Orange	Scrapped
DSC 2026	402	BTH	May 1959	September 1989	International Orange	Scrapped
DSC 2039	403	BTH	June 1959	February 1989	International Orange	Scrapped
DSC 2041	404	BTH	August 1959	September 1989	International Orange	Scrapped
DSC 2054	405	BTH	July 1959	February 1989	International Orange	Scrapped
DSC 2067	406	BTH	July 1959	September 1989	Alliance Yellow	In service	South Island	Alliance Works, Pukeuri.
DSC 2082	407	BTH	July 1959	February 1989	International Orange	Scrapped
DSC 2095	408	BTH	August 1959	October 1989	International Orange	Scrapped
DSC 2107	409	BTH	August 1959	October 1989	International Orange	Scrapped
DSC 2122	410	BTH	October 1959	February 1989	International Orange	Scrapped
DSC 2135	411	BTH	September 1959	February 1989	International Orange	Scrapped
DSC 2148	412	BTH	September 1959	October 1989	International Orange	Scrapped
DSC 2150	413	BTH	September 1959	February 1989	International Orange	Scrapped
DSC 2163	414	BTH	October 1959	September 1989	International Orange	Scrapped
DSC 2176	415	BTH	October 1959	September 1989	International Orange	Scrapped
DSC 2189	416	BTH	October 1959	September 1989	International Orange	Scrapped
DSC 2191	417	BTH	November 1959	September 1989	International Orange	Scrapped
DSC 2203	418	NZR	October 1962		Tranz Rail Blue	In service	North Island
DSC 2216	419	NZR	December 1962		Toll Rail ("Corn Cob")	Scrapped	North Island	Locomotive caught fire.
DSC 2229	420	NZR	March 1963		Tranz Rail Blue	In service	North Island
DSC 2231	421	NZR	April 1963	September 1990	International Orange	Scrapped	North Island	Used as static engine test bed after damaged in accident before scrapping
DSC 2244	422	NZR	May 1963		KiwiRail	In service	North Island	Appeared in the NZR 1970's TV commercial
DSC 2257	423	NZR	July 1963		Tranz Rail Blue	Out of service	North Island	Ravensdown, New Plymouth.
DSC 2272	424	NZR	August 1963	May 1989	International Orange	Scrapped	North Island
DSC 2285	425	NZR	September 1963		Tranz Rail Blue	Out of service	Hutt Workshops	Stored out of service at Hutt Workshops.
DSC 2298	426	NZR	November 1963	January 2004	Tranz Rail Blue	Scrapped	South Island
DSC 2312	427	NZR	November 1963		KiwiRail	In service	North Island
DSC 2325	428	NZR	November 1962		Tranz Rail Blue	In service	South Island
DSC 2338	429	NZR	February 1963		Tranz Rail Blue	In service	North Island
DSC 2340	430	NZR	March 1963		KiwiRail	In service	North Island
DSC 2353	431	NZR	May 1963		Tranz Rail Blue	In service	South Island
DSC 2366	432	NZR	June 1963		Tranz Rail Blue	In service	North Island	Icepak Longburn shunter
DSC 2379	433	NZR	July 1963		KiwiRail	In service	North Island
DSC 2381	434	NZR	September 1963	March 2004	Tranz Rail Blue	Scrapped	North Island
DSC 2394	435	NZR	October 1963	September 1998	International Orange	Scrapped	North Island
DSC 2406	436	NZR	January 1964		Tranz Rail Blue	In service	South Island
DSC 2419	437	NZR	March 1964		KiwiRail	In service	North Island	Mainly used as Hutt Workshops shunter
DSC 2421	438	NZR	November 1964	July 2002	Alliance Yellow	In service	South Island	Alliance Works, Lorneville.
DSC 2434	439	NZR	December 1964		Tranz Rail Blue	Out of service	North Island	Stored out of service at Hutt Workshops.
DSC 2447	440	NZR	February 1965		KiwiRail	In service	South Island
DSC 2462	441	NZR	March 1965		Toll Rail "Corn-Cob"	In service	South Island
DSC 2475	442	NZR	May 1965	April 2007	International Orange	Scrapped	South Island
DSC 2488	443	NZR	August 1965	May 1989	International Orange	Scrapped	North Island
DSC 2490	444	NZR	December 1964		KiwiRail	In service	North Island
DSC 2502	445	NZR	December 1964		Tranz Rail Blue	In service	South Island
DSC 2515	446	NZR	March 1965		KiwiRail	In service	North Island
DSC 2528	447	NZR	March 1965	June 2004	International Orange	Scrapped	North Island
DSC 2530	448	NZR	June 1965		KiwiRail	In service	North Island
DSC 2543	449	NZR	August 1965		Tranz Rail Blue	In service	North Island
DSC 2556	450	NZR	September 1966		KiwiRail	In service	North Island
DSC 2569	451	NZR	October 1966		Tranz Rail Blue	Under overhaul	North Island	Under overhaul at Hutt Workshops.
DSC 2571	452	NZR	December 1966	August 1990	International Orange	Scrapped	North Island
DSC 2584	453	NZR	December 1966	2003	Waitara Railway Preservation Society	Preserved	North Island	Preserved, Waitara Railway Preservation Society.
DSC 2597	454	NZR	February 1967		Tranz Rail Blue	In service	North Island
DSC 2609	455	NZR	April 1967	February 2001		Scrapped
DSC 2611	456	NZR	May 1967	June 1989		Scrapped
DSC 2624	457	NZR	June 1967		KiwiRail	In service	North Island
DSC 2637	458	NZR	August 1967	August 1990		Scrapped
DSC 2652	459	NZR	September 1967		Tranz Rail Blue	In service	South Island
DSC 2665	460	NZR	September 1966		KiwiRail	In service	North Island
DSC 2678	461	NZR	October 1966		Tranz Rail Black	In service	South Island
DSC 2680	462	NZR	December 1966		Tranz Rail Blue	Out of service	North Island	Stored out of service at Hutt Workshops.
DSC 2693	463	NZR	December 1966		KiwiRail	In service	South Island
DSC 2705	464	NZR	June 1967		KiwiRail	In service	North Island	Mainly used as Hutt Workshops shunter
DSC 2718	465	NZR	July 1967		KiwiRail	In service	South Island
DSC 2720	466	NZR	September 1967		KiwiRail	In service	North Island
DSC 2733	467	NZR	September 1967	June 2004		Scrapped
DSC 2746	468	NZR	November 1967		KiwiRail	In service	North Island
DSC 2759	469	NZR	December 1967	2002	Mainline Steam Blue	Preserved	North Island	Preserved, Mainline Steam.

External links

• NZ Rolling Stock - Preserved NZR diesels