It was intended to run under the River Thames just upstream from Hungerford Bridge, connecting Waterloo station to the Whitehall end of Great Scotland Yard.

c. cclviii) was an Act of the Parliament of the United Kingdom that authorized the construction of a pneumatic railway under the River Thames in central London.

The railway was intended to cross the River Thames through a tunnel composed of four prefabricated tube sections, each 220 feet (67 m) long, laid in a trench dredged across the riverbed.

These sections were to be joined by inserting their ends into junction chambers constructed within brick piers below the existing riverbed.

[3] The line was affected by the 1866 financial crisis, which was triggered by the collapse of the Overend, Gurney and Company bank.

[7] The trench excavated at the northern end is said to have become the wine cellar of the National Liberal Club.