Reading saw a large increase in population during the Second World War, and extra vehicles were obtained to meet the demands for transport.

Reading Corporation had run an electric tramway network since 1 November 1901, and by the 1930s the tramcars were showing their age, as the fleet still consisted of the 30 vehicles that had been bought for the opening of the system and another six that had been acquired a year later, although many had been fitted with new bodywork at the Mill Lane depot in the 1920s.

As they were already promoting a Bill in Parliament to authorise the supply of electricity, the initial plan to obtain powers to convert the Caversham Bridge to Whitley Wood route became a more general request to cover the conversion of all the tram routes, and these powers were enshrined in the Reading Corporation Act (1935).

The vehicle was fitted with a skate to allow it to run under the tramway wires between the depot and the test track, and although there was never a public trolleybus service on the Erleigh Road route, passengers were often carried free of charge during this period to provide a taster for the new mode of transport.

Trams were withdrawn from the Caversham to Whitley Street route on 15 July 1936, to be temporarily replaced by motor buses while the conversion of the overhead wiring was completed.

A formal opening took place on 18 July, with the Mayor driving the Sunbeam demonstrator, now No.1 in the corporation's fleet.

[4] The different makes of trolleybus were assessed, and an order was placed with AEC for 25 vehicles to enable the rest of the trams to be withdrawn.

Attempts to hire surplus trolleybuses or motor buses from other operators failed, but in 1942 an order was placed with Sunbeam for six utility-bodied vehicles, which arrived in 1943.

[5] On 31 July 1944 a new branch was opened from Oxford Road to Kentwood, enabling trolleybuses to replace motor buses with a consequential saving in precious oil based fuel.

Reading Corporation decided to abandon the trolleybus system, and the routes were phased out between July 1965 and November 1968.

At the same time, the wiring allowing the trolleybuses to serve the Stations was altered, in preparation for the introduction of a one-way system in the area.

The decision to abandon the system was taken at a Council meeting on 26 July 1966,[5] and large-scale closure began on 8 January 1967, when services on the Whitley Wood branch were withdrawn.

The trolleybuses continued to operate two-way, as it was considered uneconomic to erect wiring on the new inbound route, London Road.

The site also contained a power station equipped with three boilers and four steam engines, which could supply 400 kW at 500 volts for the trams.

[5] After closure of the system, the Mill Lane garage was used for motorbuses, but in 1998 the site was completely demolished to make way for the Inner Distribution Road and "The Oracle" shopping mall.

[14] However, the huge stone sign that adorned the top of the power station was saved and built into the back wall of the cinema that forms part of the complex.

Of the two from Sunbeam, the first was a demonstrator, and was obtained because it allowed driver training to begin, whereas new vehicles had a longer lead time.

The second batch was obtained to cope with increased traffic levels during the Second World War, and were probably Sunbeams, although Joyce et al. also call them Karriers.

Plans for them to enter service immediately could not be actioned, because of the poor condition of the vehicles, and a programme of rebuilding, using two of them for spares was started, although only six of them were eventually completed.

[19] The Reading Transport Society was formed in April 1961 when 14 enthusiasts decided it was worth trying to save one of the AEC vehicles due to be withdrawn later that year.