The East Lancashire Railway and Lancashire & Yorkshire Railway shared a track between Walton and Liverpool in order to save costs. The route needed a tunnel beneath Breeze Hill and in 1848 the Kirkdale Tunnel of 1,149 yards was completed.
To ease capacity constraints, the centre of the tunnel was opened out in 1904 and two new tunnels were built to the west of the original. The later tunnels are now used by Merseyrail and the 1848 bore reserved for possible future expansion.