The prototype of a fleet of 50 new trams that will begin appearing on Melbourne's network from late next year has been unveiled today by Transport Minister Terry Mulder.

Mr Mulder went to Dandenong, to train and tram manufacturer Bombardier, this afternoon to preview the mock-up of the first low-floor tram.

Bombardier was awarded the contract for the 50 new trams last year.

The trams are 33 metres long and feature a door at each end for the exclusive use of tram drivers, under a design agreed under the previous state government. There are five passenger doors on each side of the tram.

The trams are too long for many Melbourne superstops but the alignment of the doors mean that passengers will be able to get on and off despite the tram's ends jutting out off the superstops.