 The South Wales Railway Act was passed on 2 July 1847, and the SWR was authorised to rent or purchase the FODR and to divert, widen and improve it, constructing a locomotive railway.The branch to Bullo Pill was to pass under the South Wales line, permitting direct traffic to the docks, with a spur to the main line.Isambard Kingdom Brunel, as engineer of the South Wales Railway, was not satisfied with the proposed conversion because of the steep gradients involved and the uncertainty as to whether the line might continue to be worked by horses.