to allow an omnibus to leave the tracks to overtake a goods train. By the 1880s, there was an omnibus service every five minutes. An elevated railway was first proposed in 1852, and in 1878 the Mersey Docks and Harbour Board (MD&HB) obtained powers for a single-line steam railway with passing loops at stations. The MD&HB applied to the Board of Trade based on this plan, but it was rejected and there was no further progress. The Liverpool Overhead Railway Company was formed in 1888 and obtained permission to build a double-track railway in the same year. Engineers Sir Douglas Fox and James Henry Greathead were commissioned to design the railway. Steam traction was considered and they considered fitting floors to the structure to prevent ash falling to the street below, however this was seen as a fire risk. Sir William Forwood, the Chairman of the Liverpool Overhead Railway, had studied American electric railways, and in 1891 electric traction was chosen. John William Willans was chosen as the primary contractor. Building started in 1889 and was completed in January 1893. The structure was to be made of wrought iron girders a nominal above the roadway. A total of 567 spans were erected, most being long. The standard gauge railway was laid on longitudinal timbers on the elevated sections. Four bridges were constructed to cross wider streets. Hydraulic lifting sections were provided at Brunswick, Sandon and Langton Docks to allow goods access to the docks. To allow shipping access to the Leeds and Liverpool Canal, at Stanley Dock a bridge was replaced by a combined lifting and swing bridge, the lower lifting section carrying the road and goods railway. At Bramley-Moore Dock, the railway dropped to road level to pass under the Lancashire and Yorkshire Railway (L&YR) coal tip branch. As the gradient was 1 in 40 this was known as the switchback. Originally the conductor rail was placed between the rails, energised at 500–525volts DC. The power was supplied by a generating station at Bramley-Moore Dock that received its coal directly from the Lancashire & Yorkshire Railway branch line which passed above. Special lightweight passenger cars were designed with each having a driving motor car; one bogie was powered with a single motor. They were placed on the track in the switchback section. The finished railway ran between Alexandra Dock and Herculaneum Dock, though the line extended another half a