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HomeOur Collection > ZB Class

ZB Class

© Diesel Traction Tasmania

Freshly refueled 2122(ZB3) and another ZB sit next to idling DQ2006, June 2013.

© Clynton Brown

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Number Status Location
2352 / ZB3 / 2122 Awaiting Collection East Tamar Junction TMD, TasRail
Built byGeneral Electric Company Australia, Rocklea Works, Brisbane, Queensland
Introduced byAustralian National - TasRail
Numbers Carried2350 - 2361, 2370 - 2373, ZB1 - ZB16, 2120 - 2129
Total (In Tasmania)16
Total Preserved0
EngineEnglish Electric 12CSVT MKIII
Main AlternatorToyo Denki TY-WD10314A-10A
Traction MotorsEnglish Electric 548 x 6
Wheel ArrangementCo - Co
Brakes Fitted26L Air Brake
Power Rating2350hp / 1950hp*1750kW / 1470kW*
Weight90T / 96T*91.4t / 97.5t*
Length52ft 9in16.1m
Starting Tractive Effort78010lbf347kN
Continuous Tractive Effort53950lbf240kN
Load Limit (1 in 40 Gradient)492T500t
Axle Weight15T / 15ūT*15.2t / 16t*
Fuel Capacity1442gal5460l

Additional technical data:

Aspiration: Turbocharged

Auxiliary Generator: CD344A-4A

Air Compressor: Gardner Denver WXE-A  

Wheel Slip control: Bridged Relay

Vigilance: Davies & Metcalf

Control Voltage: 110V

Gear Ratio: 72:15

Wheel Diameter: 952mm

Lubricating Oil Capacity: 545l

Cooling Water Capacity: 1000l

Sand Capacity: 0.68m3

Throttle Control: Pneumatic

* Original max power - de-rated to increase reliability. Some locos ballasted to increase TE.


All details listed relate to the time that locomotives spent in Tasmania. See 'Overview' for other historic information.

Sixteen 2350 and 2370 class locomotives were built from 1973 for coal haulage on the Queensland Railways, the major differences in the two classes being a single driving position in the later group of four locos. Following mainline electrification in Queensland the locomotives became surplus to requirements and were sold to AN and gradually shipped to Tasmania in 1987 and 1988. They were then classed ZB, and renumbered in the same order as their original Queensland numbers. In Tasmanian service, the ZB class displaced most of the remaining 830 class and any remaining mainline vacuum braked services. They were able to be used in multiple with the older ZC class when these locomotives were purchased from Queensland. Whilst high powered and generally well performing, the ZB class became a victim of the reduction in maintenance in the dying days of AN, and the anti-EE bias of the new private ownership, and the locos received minimal maintenance and their usage curtailed. Despite this, many consider their finest hours being toward the end of the AN era when four loco regularly hauled 70 wagons north from Hobart of an evening.

Some locomotives ran in the Queensland blue and white colours for up to five years before being repainted in the AN colour scheme (generally green and yellow, although ZB12 received the reversed Yellow and green livery). Three locos have been written off and scrapped due to accident damage, while ZB9 and ZB6 have been rebuilt to ZR/ZP class. In late 2002, three operational locos and one non-operational loco were sold to South Spur Rail in Perth, Western Australia. Locos 2120, 2125 and 2129 we shipped shipped to Perth at a rate of one per month in early 2003, while 2124 was purchased for parts and was stripped and scrapped in Tasmania in April 2004.

ZB12 was experimentally painted yellow in 1992, with the remaining serviceable locomotives at the time being repainted yellow from late 1996. During 1998, locos 2122 and 2123 were modified to allow the loco to be driven in either direction for single unit operation. From June 1998, all operational ZB locomotives were renumbered to the 2120 series. The remaining stored/stripped locos were scrapped in 2011 and 2012, leaving three operational (2122, 2123 and 2128) and one stored locomotive (2121) in Tasrail ownership and are are mainly used on ballast trains and as shunt locos at East Tamar and Boyer. With the arrival of and entry into service of the new TR class, the final ZB class units were withdrawn and set aside at East Tamar Junction Workshops. [info. courtesy]

Updated Admin on 23/08/2017 22:16
Created Admin on 25/03/2011