Yellow Bus Garage

This bus garage, originally also for trolleybuses, was built between 1950 and 1951 by Jackson and Greenen for Bournemouth Corporation, with Alfred Goldstein acting as a consultant structural engineer. The building is of brick construction and features a remarkable reinforced concrete thin shell roof. This roof is composed of nine cylindrical vaults, each 21 1/2 inches thick and connected by integral edge beams at the valleys. The entire roof structure was post-tensioned using a Magnel-Blaton system of prestressing cables within the beams. Each shell has a radius of 22 feet 10 inches and a span of 33 feet. The garage forms a clear span shed of 300 feet by 150 feet, with a narrow, single-storey office area along the south side and smaller offices located within the building on the north side. The elevations are constructed with two-tone brickwork, featuring projecting brick headers and double folding timber doors to both the front and back. Pairs of notches are positioned above the doors to accommodate trolleybus wires, and unbonded brickwork creates patterned panels of contrasting brick on either side. A wavy concrete canopy on the left return reflects the shape of the roof above, which is clearly visible through clerestory glazing. The unbonded brick panels, similar to the projecting headers, represent a good example of Scandinavian-inspired decorative detailing popular during that period. Petrol pumps are situated on the north side. A contemporary concrete-framed wash house with brick infill and a concrete roof adjoins the garage. At the time of its construction, the 150-foot span was the largest achieved using shell construction in Britain, being the first to employ post-tensioning techniques. Its publication in 1952 contributed to the widespread adoption of this construction method. The roof incorporates stop-chamfered spine beams with run-out stops.