Britain. The track also contained automatic braking systems for trains which ran through a red light; the current could be automatically disconnected and air brakes applied. The seventeenth and final station was opened on 16 June 1930, at Gladstone Dock, between Alexandra Dock and Seaforth Sands stations. Plans were put forward to extend the line from Herculaneum Dock to St Michaels, and from Seaforth Sands to Sefton, to create a circular route, using the Hunts Cross to Southport line, however, these were never carried out. With fewer ships docking in Liverpool during the Great Depression, there was a reduction in usage for the Overhead Railway. Tourist tickets were offered from 1932, which also included visits to ocean liners that were moored at the docks, as part of a scheme to increase ticket sales, along with reduced prices, and a major advertising campaign. During World War II, the railway suffered extensively from bomb damage. As a purely local undertaking, it was not nationalised in 1948 with the rest of the British railway system. In the late 1940s and early 1950s, the company started to modernise some of the carriages, incorporating sliding doors. The line continued to carry large numbers of passengers, especially dock workers. The Mersey Docks & Harbour Board maintained stringent controls over the operation of the Overhead Railway for the duration of its operation. The board protected its own freight transport interests by including clauses in the Overhead Railway's enabling legislation to limit the weight of parcels that could be transported, and renewing the lease on it every seven years. The board blocked an attempt by the Liverpool Overhead Railway Company to extend its line to join the Lancashire & Yorkshire Railway at Seaforth for the purposes of transporting coal to Herculaneum Dock. The lack of development or rescue by the board was at least in part due to its determination to restrict its activities to those that directly impacted the dock. Closure The railway was carried mainly on iron viaducts, with a corrugated iron decking onto which the tracks were laid. It was vulnerable to corrosion, especially as the steam-operated Docks Railway operated beneath some sections, despite the locomotives being fitted with chimney cowls which were intended to deflect the steam from the structure. Parts of the decking had become rusty on the surface, caused by steam and soot from the dock locomotives that passed underneath, mixing with