B-class trams are three-bogie articulated trams that operate on the Melbourne tram network. Following the introduction of two B1-class prototype trams in 1984 and 1985, a total of 130 B2-class trams were built by Comeng (later ABB), Dandenong for the conversion of the St Kilda and Port Melbourne railway lines to light rail. They were the first articulated air-conditioned trams on the Melbourne tram network. These trams also include dot-matrix destination signs, and although the electronics of the B2-class were similar to earlier Z3 and A-class trams, they were fitted with gate turn-off control systems. In 2007 the dot-matrix displays were replaced with LED equipment and cab air-conditioning fitted in 2009. In 2014, an upgrade of the interiors commenced. Seats were removed and replaced with 'lean seats' as fitted on C and C2 class trams, that increases capacity by seven to nine passengers while providing space for prams and shopping carts, while extra hand rails will also be installed floor to ceiling, and seats will be re-covered. These changes were aimed at increasing capacity while providing better use of space and flow through the vehicles. Step-well lighting was also improved, providing better visibility by changing to LED lighting. The program aimed to add capacity of approximately 1,100 passengers to the B-class fleet and was completed in early 2014. In mid-2015, the installation of automated onboard passenger information system, similar to that used on the E class fleet, commenced at Camberwell depot. This also changed over the entire B class fleet destination displays from the previously fluorescent-lit dot-matrix to the more visible, bright orange LED type seen on the Z3 class.