Z-class Melbourne tram

Z-class
Z3 139 on Swanston Street in December 2013
Manufacturer	Comeng
Assembly	Dandenong
Constructed	1975–1983
Number in service	114 (May 2016)
Fleet numbers	Z1 1-Z1 115 Z2 116-Z2 130 Z3 131-Z3 230
Capacity	Z1/Z2: 48 Z3: 42 (Seated) 70 (Standing)
Depot(s)	Brunswick Essendon Glenhuntly Malvern
Specifications
Train length	Z1/Z2: 16.00 m (52 ft 6 in) Z3: 16.64 m (54 ft 7 in)
Width	2.67 m (8 ft 9 in)
Height	Z1/Z2: 3.55 m (11 ft 8 in) Z3: 3.41 m (11 ft 2 in)
Doors	Z1/Z2: 4 Z3: 6
Weight	Z1/Z2: 19 t (19 long tons; 21 short tons) Z3: 21.8 t (21.5 long tons; 24.0 short tons)
Traction motors	Z1/Z2: 4 x ASEA LJB 23/2 57 kW Z3: 2 x AEG ABS 3322 195 kW
Electric system(s)	600 V DC catenary
Current collection method	Pantograph
Bogies	Z1/Z2: ASEA/GS type 28 Z3: Duwag
Track gauge	1,435 mm (4 ft 8 1⁄2 in)

The Z-class are single-unit bogie trams that operate on the Melbourne tram network. Between 1975 and 1983, 230 trams spanning three subclasses were built by Comeng, Dandenong. The design was based on two similar , and a prototype built by the Melbourne & Metropolitan Tramways Board. While the Z1 and Z2-class trams were very similar, the Z3-class had significant design changes.

Since introduction they have had a variety of liveries, and modifications. The Z1 and Z2-class trams have been retired, with 114 Z3-class trams remaining in service.

When Melbourne & Metropolitan Tramways Board (MMTB) staff were sent to Europe in 1965 to investigate other tramway operations, they took interest in Swedish trams, and upon return in 1966 drew up specifications, and had a timber mockup built. This mockup was to be the basis for a new tram design for Melbourne. The MMTB approved of the design, and in 1972 requested a prototype be constructed, the result was PCC 1041 being built at Preston Workshops. It was 'European in appearance' and utilised components bought new, and recycled from an earlier prototype tram, PCC 980. Prototype PCC 1041 became the basis of the Z-class trams, with 230 trams influenced by the Gothenburg, Sweden , built by Comeng, Dandenong between 1974 and 1983.

Between 1995 and 1999, the remaining 106 Z1s and Z2s were refurbished by Goninan. The bodies were overhauled in an area of Preston Workshops allocated to Goninan while the bogies were sent to Goninan's Auburn, New South Wales facility. On all bar four, the flap type destination displays and route number indicators were replaced by dot-matrix displays.

When the Melbourne tram network was privatised in August 1998, M>Tram were allocated 94 Z1s, 12 Z2s and 84 Z3s while Yarra Trams received 31 Z3s. All were reunited under common ownership in December 2002 when the networks were reunited.