In 1861, the LNWR received Parliamentary approval to build a line crossing the Mersey from Aston southeast of Runcorn, to join the line from Crewe to Warrington at Weaver Junction west of Widnes, where it met the line from Warrington to Garston at Ditton Junction. The line was long and reduced the distance between Liverpool Lime Street and the stations south of the River Weaver by more than . The bridge at Runcorn gap was the responsibility of William Baker, the chief engineer of the LNWR.