The Mersey Railway was the first part of the passenger railway connecting the communities of Liverpool, Birkenhead, and now the rest of the Wirral Peninsula in England, which lie on opposite banks of the River Mersey, via the Mersey Railway Tunnel. The railway opened in 1886 with four stations using steam locomotives hauling unheated wooden carriages; in the next six years the line was extended and three more stations opened. Using the first tunnel under the Mersey the line is the world's oldest underground railway outside London. Because the steam locomotives created a polluted atmosphere in the tunnel, many passengers reverted to using the river ferries and the railway was bankrupt by 1900. Recovery came after the railway adopted electric traction in 1903. The Mersey Railway remained independent after the railway grouping of 1923, although it became closely integrated with the electric train services operated by the London, Midland and Scottish Railway over the former Wirral Railway routes after 1938. The Mersey Railway was nationalised, along with most other British railway companies, in 1948. The tunnel and railway are still in use today as part of the Wirral Line of the Merseyrail rail network. History Origins Records exist of a ferry service across the River Mersey between Birkenhead on the west bank and Liverpool on the east since the middle ages. In 1332 the monks of Birkenhead Priory were granted exclusive rights to operate a ferry; following the dissolution of the monasteries these rights passed through a number of operators eventually to the township of Birkenhead. It is recorded that Marc Isambard Brunel suggested a road tunnel when designing the Birkenhead docks and from the 1850s a railway tunnel under the Mersey was proposed several times. The Mersey Pneumatic Railway received Royal Assent for a single line pneumatic railway in 1866 but failed to raise the necessary capital. In 1871 the Mersey Railway was given the necessary permissions for an orthodox two track railway connecting the Birkenhead Railway near their station through a tunnel under the Mersey to an underground station serving Liverpool. However the company found it difficult to raise the necessary funds until Major Samuel Isaac undertook to build the railway in 1881. He contracted construction to John Waddell, who appointed Charles Douglas Fox and James Brunlees as Engineers. Construction of the river tunnel started from two deep shafts, one on each bank, containing water pumps. Three tunnels