Opened on 8 November 1919 (1919-11-08),[1][2] it was unusual in being a completely new system that was not replacing any previously operating tramway network.

[3] From 1912 Bolckow Vaughan was the main mover behind the North Ormesby, South Bank, Normanby and Grangetown Railless Traction Co.,[4] which built a depot at Cargo Fleet, took power (until 1955[4]) from the Bolckow Vaughan's (later Dorman Long) South Bank steel works, erected the first pole at Normanby in July 1915 and had the entire system ready 8 months later, but not the buses, which were held up by wartime shortages.

[5] In December 1918, the company was sold, 1/3 to Middlesbrough Corporation and 2/3 to Eston Urban District Council.

[4] The original routes were Smeaton St – North Ormesby – Cargo Fleet – South Bank – Normanby, or Grangetown Market Sq.

In 1966 the Eston and Normanby routes were to be linked, but United objected, so the circle was not opened until 31 March 1968; the last UK trolleybus extension.