The St Helens trolleybus system opened on 11 July 1927, gradually replacing the St Helens tramway network.
By the standards of the various now-defunct trolleybus systems in the United Kingdom, the St Helens system was a medium-sized one, with a total of six routes, and a maximum fleet of 66 trolleybuses. It was closed on 30th June 1958.
The 16 youngest trolleybuses in the fleet at that time, ones built in 1950–51, were all sold to other systems for further use. Eight Sunbeam vehicles went to South Shields system and eight British United Traction vehicles to Bradford.
Only one of the former St Helens system trolleybuses is now preserved, at the Trolleybus Museum at Sandtoft, South Yorkshire.
A trolleybus (also known as trolley bus, trolley coach, trackless trolley, trackless tram or trolley is an electric bus that draws power from overhead wires (generally suspended from roadside posts) using spring-loaded trolley poles.
Two wires and poles are required to complete the electrical circuit. This differs from a tram or streetcar, which normally uses the track as the return path, needing only one wire and one pole (or pantograph).
They are also distinct from other kinds of electric buses, which usually rely on batteries. Power is most commonly supplied as 600-volt direct current, but there have been, and are, exceptions.
Currently, around 300 trolleybus systems are in operation, in cities and towns in 43 countries.