Initially limestone was quarried from the immediate area near the tunnel, but as more of it was used, work began on the Wren’s Nest Tunnel that linked Castle Mill Basin to the limestone mines at Wren’s Nest. It was over half a mile long and was linked to the mines by many tramways and foot tunnels.

Limestone was blasted from the roof and sides of the mines in pieces weighing as much as 100 tons, which would fall to the bottom and break-up into smaller pieces. The limestone was then loaded onto tramway wagons and taken to the canal to be loaded onto boats, which were about 30 feet long by 5 feet 6 inches wide and could carry about 10 tons of stone.

The boatmen propelled the boats using long poles pushed against the tunnel roof, or where space allowed, they would be "legged" by boatmen lying on their backs and walking along the sides or roof of the tunnel with their feet.

By the middle of the 19th century, most of the limestone near the main tunnel was worked out and so mining became concentrated on Wren's Nest Hill.

As built, the main tunnel was unlined, but due to pieces of rock falling from the roof, a brick lining was added in 1816, except in areas where there was rock movement due to the many faults in the area.

In the mid 19th century the tunnel was extremely busy. Over 100 boats per day used the tunnel, carrying coal, limestone, iron ore, timber, clay and items manufactured in the local factories. Because boats could not pass each other in the narrow tunnel, a timetable had to be drawn up and boats went through in convoys from each end, at certain times.

A narrow boat leaving the Dudley Tunnel. From a postcard posted in 1908.

Part of the main tunnel.

In 1858 the Netherton Tunnel opened with a tow path on either side of the canal so that boats pulled by horses could go through the tunnel and pass one another. Both tunnels continued to be heavily used until the later part of the 19th century when railways began to take trade from the canals. At this time more of the remaining traffic used the Netherton Tunnel in preference to the narrow Dudley Tunnel, which had to be rebuilt at the southern end in 1884, due to mining subsidence.

By the 1930s, road transport began to greatly reduce canal transport and by the early 1950s, less than half a dozen boats passed through the Dudley Tunnel each week. The numbers rapidly fell and in 1959 British Waterways decided that the tunnel should close. A protest cruise was held in October 1960, but in spite of strong protests from canal societies, the tunnel was officially abandoned by British Waterways in 1962.

Castle Mill Basin.

On the 1st January, 1964, a group of canal enthusiasts formed the Dudley Canal Tunnel Preservation Society, which soon had several hundred members.

The society organised trips through the tunnel and gave talks to other societies and organisations, also managing to publicise their campaign on radio and TV. They were eventually acknowledged by British Waterways and in 1970 became the Dudley Canal Trust.

In 1968, the railway bridge that passed over the northern end of the tunnel was declared unsafe and so British Railways decided that it should be replaced by an embankment that would completely cover the tunnel.

By the late 1960s, the railway was largely used for goods and in 1968 it became a victim of the Beeching cuts. It was completely closed and so the embankment was never built.

People’s attitudes to the canals were changing and in 1968 the government announced that the membership of the Inland Waterways Amenity Advisory Committee (IWAAC), would include members from the Inland Waterways Association, which campaigned for the conservation and restoration of the British canal network.

Many volunteers became involved in the project to restore the canal and the tunnel to their former glory. Dudley Corporation became the first local authority to finance canal restoration, announcing that they would fund half of the repair costs for the tunnel branch, as well as landscaping the derelict land at Park Head, around the southern end of the tunnel. Thanks to help from British Waterways and Dudley Borough Council, around 50,000 tons of mud and debris were dredged from both ends of the tunnel and the locks to the south were restored.

At Easter 1973, the tunnel was reopened and around 300 boats and 14,000 visitors came to the event. The trust began running boat trips into the tunnel and a boat was converted to use a battery-powered electric motor in 1975. By August 1977, the Dudley Canal Trust had carried around 25,000 visitors through the tunnel, but subsidence near the southern end led to its closure in 1979. It took many years to find sufficient funds for the repairs. Grants from several organisations including the European Regional Development Fund, totalling around three quarters of a million pounds, enabled the brick lining to be removed from a section, 110 yards long and replaced with a concrete tube. The tunnel reopened in 1992.

Some of the limestone workings beside the canal in the Dudley Tunnel.