This was done in a large scale operation in 1872, and in a short space of time the broad gauge had been eliminated on South Wales, enabling the GWR to develop mineral haulage from the area to London, West of England and South Coast destinations. The "Gloucester and Berkeley Canal", usually known later as the "Gloucester and Sharpness Canal", was built between 1798 and 1827, to give sea-going ships access to Gloucester. It was the first ship canal in Great Britain. There was a sea lock at Sharpness, on the eastern shore of the Severn. By 1870 the canal was inadequate for the ships of the day, which discharged at Sharpness, and required to bunker. In 1871 work was started on docks at Sharpness, as a convenient place to which larger sea-going shipping could be brought. The Midland Railway was operating the main line between Bristol and Gloucester, and the Midland obtained authorisation for a branch line from Berkeley Road on that line to Sharpness. The idea of a bridge over the River Severn had long been held. Brunel's first intention for the South Wales Railway was for the line to cross the Severn by bridge, at Hock Cliffe between Fretherne and Awre. This was strenuously opposed in Parliament in 1845 by interests in Gloucester, which strongly wished the line to pass through their city, and Brunel was obliged to take the line round through Gloucester. In 1865 there was a sudden upsurge of interest in a bridge or tunnel; the bridge was proposed by the "South Wales and Great Western Direct Railway", which proposed a line similar to the later Wootton Bassett -- Badminton -- Pilning line, but crossing the Severn from Oldbury Sand to Chepstow, a little north-east of the 1966 Severn Road Bridge. Because of shipping requirements at this location, the bridge had to be designed to give a high clearance over the water, and this proposal was known as the High Level Scheme. Two more groups proposed bridges further up river, near Newnham and at Hock Crib respectively. Although these ideas gained considerable traction, all of them were withdrawn without any construction taking place. In the latter half of 1871 a revival of interest took place, and six schemes for a Severn Railway Bridge were promoted. Some of them had ambitious connections to distant networks; the South Midland Railway would run from Lydney over the Severn to join the London and South Western Railway at Andover and Basingstoke.