The Bellman Hangar was designed in the United Kingdom in 1936 by the Directorate of Works structural engineer, N. S. Bellman, as a temporary hangar capable of being erected or dismantled by unskilled labour with simple equipment and to be easily transportable. Commercial manufacturing rights were acquired by Head Wrightson & Co of Teesdale Iron Works, Thornaby-on-Tees. By November 1938, 10 had even been supplied to Russia.
During World War I and for some time after, the only successful transportable hangar design was the Bessonneau hangar. This could be very quickly erected and secured to provide adequate shelter for a few small aeroplanes. But with post-war increases in the number and size of aeroplanes, the need for larger transportable accommodation soon became apparent. The Air Ministry therefore issued a specification in 1936 covering the dimensions and requirements for a light transportable shed for use in war. It had to be end-opening with doors at both ends, be capable of mass production and have interchangeable parts to permit rapid erection and dismantling with minimal permanent foundations. This specification was submitted to various designers and eventually two different designs were presented - the Bellman and the Callender Hangar.
An example of each was erected at two demonstration sites (airfields) in the north-east: at RAF Thornaby an Air Ministry design was built (later to be known as the Bellman hangar) and at RAF Usworth a Callender Cable & Construction design was built (later to be known as the Callender-Hamilton hangar). In 1938, the Bellman design was chosen as the standard Air Ministry wartime transportable shed, but Callender-Hamilton hangars were also purchased in small numbers for Royal Naval Air Stations until superseded by a new hangar type in 1943.
The Bellman hangar was designed in 1936 by N S Bellman (an Air Ministry Directorate of Works structural engineer) and its general dimensions were 175 ft long, 95 ft wide (87 ft 9in clear width) and 25 ft (clear height). It was constructed in 14 bays at 12 ft 6in centres based on a unit system of rolled steel sections; both walls and roof used the same standard units joined at the junction of wall and roof by a standard corner unit.
The time taken for 12 men to erect the hangar at Thornaby, including levelling the ground, laying door tracks, erecting the steelwork, and fitting oiled canvas doors, was 500 man-hours. Two light jib derricks using timber poles were required to erect the fabricated vertical and side members. The roof trusses were assembled on the ground before being lifted into position.