New Zealand DSC class locomotive
|New Zealand DSC class|
DSC class locomotive 2693 at Dunedin
|Builder||British Thomson-Houston (18),
NZR Hillside Workshops and Addington Workshops (52)
|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)|
|Locomotive 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.
|Top speed||64 km/h (40 mph)|
|Power output||315 kW (422 hp)|
|Tractive effort||46 kN (10,300 lbf)|
|Railroad(s)||New Zealand Railways, Tranz Rail, Toll Rail, KiwiRail|
|Number in class||70|
|Number||Early numbers: 400–469
TMS numbers: 2000–2759
|Locale||All of New Zealand|
|Disposition||44 in service; 25 withdrawn; 2 preserved|
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 DS and DSA class locomotives and would be suitable for replacing the BB, C, and WF 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 DSC 400-417, entered service in 1959-60 and were allocated to Auckland and Frankton Junction (Hamilton). For a time in 1962, DSC 402 was dispatched to Picton to shunt the NZR road/rail ferry MV Aramoana until newly constructed Addington DSC 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.
In the late 1970s, NZ Rail decided to undertake a re-engining programme for the DSC 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 DSC 400) was scrapped at Hutt Workshops in 1990. The eighteenth locomotive, DSC 2067 (DSC 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 (DSC 453) was sold to the Waitara Railway Preservation Society for use on their passenger trains between Waitara and Lepperton. The other, DSC 2759 (DSC 469) was sold to the Mainline Steam Trust and is used as the depot shunting locomotive at Plimmerton along with Bagnall TR 534.
|Key:||In service||Out of service||Auckland Transport service||Preserved||Overhaul/Repair||Scrapped|
|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 White||In service||South Island|
|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||Privately owned by Ravensdown. Stored in New Plymouth not running.|
|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||South Island|
|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||Alliance Yellow||Preserved||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||Tranz Rail Blue||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||In service||North Island|
|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||Waitara Railway Preservation Society, Waitara.|
|DSC 2597||454||NZR||February 1967||June 2003||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 ("Bumble Bee")||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||Tranz Rail Blue||In Service||South Island|
|DSC 2720||466||NZR||September 1967||Toll Rail ("Corn Cob")||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||Mainline Steam Blue||Preserved||North Island||Mainline Steam, Plimmerton.|
- The frame of NZR-built DSC 2231, which was not fitted with shunter's refuges, was used as a testbed for overhauled Cummins engines after being withdrawn following collision damage in the 1980s.
- "New Zealand RailTrack". Retrieved 21 August 2010.