[1] Because the steam locomotives created a polluted atmosphere in the tunnel despite the forced ventilation system, many passengers reverted back to using the river ferries making the railway bankrupt by 1900.

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.

[3] 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.

[4] Construction of the river tunnel started from two 180 feet (55 m) deep shafts, one on each bank, containing water pumps.

[6] The geology of the riverbed meant that the plans were changed and at the deepest section the drainage and ventilation tunnels combined.

Green Lane and Birkenhead Central were below ground level in open cuttings whereas James Street and Hamilton Square were deep underground and accessed by lifts.

[11] The railway opened with steam locomotives hauling four-wheeled 27 feet (8.2 m)-long wooden carriages, with first-, second- and third-class accommodation provided in unheated compartments.

At off-peak times this was reduced to a train every 7+1⁄2 minutes, alternately from the Rock Ferry and Birkenhead Park branches.

[17] Two years previously the company had been declared bankrupt and receivers appointed, because it was unable to pay the charges on its debt.

Steam locomotives running at five-minute headways left a dirty atmosphere in the tunnel that the mechanical ventilation was unable to remove, so many passengers preferred the ferries.

In 1897 a new board of directors was elected, and in 1898, £500 was released for further expert advice that recommended electrification at a cost of £260,000[19] (equivalent to £36,580,000 in 2023).

[21] Westinghouse considered the railway would be profitable with electric traction and undertook to fund the project, promising to complete in eighteen months.

[24][25] The new electric multiple units, initially marshalled as 2-car or 4-car sets, had British-built wooden bodies on US bogies.

[28] In 1923, automatic signalling was commissioned at Liverpool Central[29] and in 1927 the island platform was widened, the work being completed in a weekend.

[28] The maximum number of cars in a train was raised to six in 1936, after the tunnels at the east end of Liverpool Central had been extended.

The Wirral had authority to electrify its lines, but had not done so, and passengers making through journeys had to change at Birkenhead Park.

[33] In 1938 the LMS introduced new lightweight three car multiple units that were later, under British Rail, to be classified Class 503.

The tunnel and railway are still in use today as part of the Wirral Line of the Merseyrail commuter rail network.

Georges Dock Pumping Station on Mann Island in Liverpool is a grade II listed building.

[38] For the opening of the line, eight powerful 0-6-4 tank locomotives were obtained from Beyer, Peacock and Company, fitted with condensing apparatus for working in the tunnel.

8 for £650; but not before Alexandra (Newport and South Wales) Docks and Railway had bought all six of the Class II locomotives for £3,450.

Unheated accommodation was in saloons and the wooden bodies were British built, and the bogies had been made by Baldwin Locomotive Works in America.

The livery was maroon with white roofs and "Mersey Railway" in gold leaf on the upper fascia panels.

[50] Air brakes were provided with storage reservoirs that were recharged from static compressors at the terminal stations.

1, a first-class motor coach, was destroyed in a fire at Derby Litchurch Lane Works, where it had been taken for overhaul in preparation for restoration and preservation.