A class Melbourne tram

A-class
A2 273 in Yarra Trams livery in December 2009
Manufacturer	Comeng
Assembly	Dandenong
Constructed	1983–1987
Number built	70
Number in service	69
Fleet numbers	A1 231-A1 258 A2 259-A2 300
Capacity	40 (Seated) 65 (Standing)
Depot(s)	Camberwell East Preston Glenhuntly Kew Southbank
Specifications
Train length	15.01 m (49 ft 3 in)
Width	2.67 m (8 ft 9 in)
Height	3.34 m (10 ft 11 in)
Doors	6
Wheelbase	1.8 m (5 ft 11 in)
Weight	22.2 t (21.8 long tons; 24.5 short tons)
Traction motors	2 x AEG ABS 3322 195 kW (261 hp)
Electric system(s)	600 V DC catenary
Current collection method	Pantograph
Bogies	Duewag
Track gauge	1,435 mm (4 ft 8 1⁄2 in) standard gauge

The A-class are single-unit bogie trams that operate on the Melbourne tram network. Seventy were built by Comeng, Dandenong between 1984 and 1987 in two batches, 28 A1s and 42 A2s, with only minor differences. They are the smallest trams by capacity currently operating on the network.

Comeng had expected an extension to the Z-class order, and in the early 1980s drew up plans for a Z4-class, due to a change in state government in 1982 these plans were put on hold. The order eventuated however in late 1982, as an order for 28 A-class trams. The design, which was shaped by input from passengers and tramway employees, had a series of alterations from the Z-class design. They did not include the conductors console seen in the Z-class, and had a differing door arrangement that posed a design challenge, as there was less space to house equipment.

This order was extended in 1985 by 42, these were designated A2-class due to a number of design changes. All 70 A-class trams were built by Comeng's Dandenong factory, with 69 remaining in service. When the Melbourne tram network was privatised in August 1999, all passed to Yarra Trams.

A few had their roller blinds replaced with dot matrix equipment in 2005/06, before all were fitted with LED equipment in 2007. All were fitted with cab air-conditioning in 2007.

As of 2017, an automated onboard passenger information system was being rolled out.

In late 1982 the state government approved an extension to the Z class order, the result being 28 A1-class which were built in 1983 and 1985. They were substantially based upon the Z-class design, with improved ventilation, and differing door positions. They had the same equipment as the Z3-class trams, AEG controls and Duewag bogies. However, placing all the Z3-class equipment under the frame posed a problem due to the differing door arrangement, as there were two step-wells where previously there was one, reducing the available space. Due to a desire to be less pointy and possess a flatter front, they were made shorter with less overhang, giving them a different appearance to the Z-class trams. The first A-class was delivered on 12 December 1983 and entered service on 13 June 1984.