ADK/ADB class railcar
ADK 682 on a Papatoetoe to Westfield service, during its farewell trip
In service	Australia: 1967–1993, New Zealand: 1993–2014, Mozambique: 2017–present
Manufacturer	ADK: Commonwealth Engineering ADB: Western Australian Government Railways
Built at	ADK: Granville ADB: Midland Railway Workshops
Replaced	Australia: WAGR Dd class & carriages New Zealand: 56-foot carriages
Constructed	1967–1968
Entered service	Australia: 1968 New Zealand: 1993
Refurbished	2007
Number built	10 sets
Number in service	8 sets (running in pairs)
Formation	Australia: ADK+ADB New Zealand: ADK+ADB+ADB+ADK (originally ADK+ADB)
Fleet numbers	ADK 681–ADK 690 ADB 771–ADB 780
Capacity	ADK: 74, ADB: 64
Operators	Australia: Western Australian Government Railways, Westrail New Zealand: Tranz Metro, Transdev Auckland Maputo, Mozambique: MetroBus
Depots	Australia: Claisebrook New Zealand: Westfield
Lines served	Australia: Armadale Fremantle Midland New Zealand: Eastern Line Southern Line Western Line
Specifications
Car body construction	ADK: 20.20 m (66 ft 3 in) ADB: 15.85 m (52 ft 0 in)
Train length	37.75 m (123 ft 10 in) per two-car unit
Car length	ADK: 21.09 m (69 ft 2 in) over couplers ADB: 16.66 m (54 ft 8 in) over couplers
Width	2.74 m (9 ft 0 in)
Height	3.92 m (12 ft 10 in)
Floor height	1.1 m (3 ft 7 in)
Entry	1.1 m (3 ft 7 in)
Doors	Air-operated sliding doors, 2 pairs each side (ADK), one pair each side (ADB), 0.915 m wide
Maximum speed	90 km/h (56 mph)
Weight	ADK: 33.3 t (32.8 long tons; 36.7 short tons) ADB: 15.8 t (15.6 long tons; 17.4 short tons)
Prime mover(s)	2 x Cummins
Power output	ADK: 2 x 155 kW (208 hp), one engine per bogie
Transmission	Diesel-hydraulic
Auxiliaries	ADB: diesel alternator in former cab (one per four-car set)
HVAC	Heating only
UIC classification	(1A)(A1)+2′2′
Braking system(s)	Electro-pneumatic
Coupling system	Australia: Norwegian coupling NZ: Kidney link & pin
Multiple working	Within class
Track gauge	1,067 mm (3 ft 6 in)

The ADK class are a class of diesel multiple units that were previously operated by Western Australian Government Railways (WAGR) in Perth, and later Transdev Auckland on Auckland's suburban rail network, and are currently operated by MetroBus in Maputo, Mozambique. Originally built by Commonwealth Engineering and the Midland Railway Workshops for WAGR in the late 1960s, all but one were sold in 1993 to New Zealand Rail, and were then owned by Auckland Transport. The units were completely withdrawn from service in New Zealand on 5 December 2014, following completion of electrification of Auckland's network.

History

In 1967 and 1968, ten two-carriage stainless steel sets were manufactured for the Western Australian Government Railways. Each set consisted of an ADK power car manufactured by Commonwealth Engineering, and an ADB trailer built by the WAGR's Midland Railway Workshops. The ADK cars were manufactured in Granville and railed via Melbourne and Adelaide requiring a change of bogies at each of these locations and again at Kalgoorlie.^[1][2]

Following the electrification of the Perth rail network, they were rendered surplus and in 1992, all except ADK 689 were sold, along with the newer ADL/ADC class, to New Zealand Rail to replace 56-foot carriages on suburban trains in Auckland.^[1][2][3][4]

In October 1993, prior to being privatised, New Zealand Rail sold the class to the Auckland Regional Council (ARC).^[5] In 2004, the ARC funded an upgrade, which included refurbishment of the interiors, painting in the new MAXX blue colour scheme and mechanical improvements to extend their life by 10 years. After the upgrade, they ran as four-car rather than two-car sets. All were refurbished except ADB 773 (in use at Lock 'n' Load paintball arena) and ADK 689 (which was not exported to New Zealand). Westrail planned on converting ADK 689 to a self-propelled track inspection carriage but this did not eventuate.

Unlike the ADL/ADC class and SA sets, the units were not fitted with Electronic Train Protection (ETP) equipment, owing to their imminent replacement by the AM class. All are scheduled for withdrawal by late 2014.^[6]

As of 15 September 2014^[update], all services on the Manukau Line are operated by the AM class. As a result of this, all ADK units were placed into storage. Services to Papakura formerly run by ADKs are now run by ADLs, also displaced from the Manukau Line. A farewell trip was run by the Railway Enthusiasts Society on 16 November 2014, running on every suburban line in Auckland.^[7] The units were completely withdrawn on 20 July 2015.

Mozambique

In August 2017, eight units were shipped to Mozambique,^[8] with one unit being purchased by the New Zealand Special Air Services for training. The shipped units are now running in Maputo, Mozambique, operated by MetroBus on a commuter service from Maputo Central Railway Station to the suburb of Matola .^[9][10]