In 1959 the British Transport Commission sought to close the tunnel but this led to an Inland Waterways Association-organised massed protest cruise in 1960.

It authorised a route that started in two fields called Great Ox Leasow and Little Ox Leasow, a little to the south of the tunnel site near Peartree Lane in Dudley, and ran southwards to an end-on junction with the Stourbridge Canal, authorised by a separate act on the same day.

[3] Quite separately, Lord Dudley and Ward was mining limestone in the Castle Mill and Wren's Next area, further to the north.

The tunnelling was then supervised by Isaac Pratt, one of the Stourbridge and Dudley committee members, with Abraham Lees continuing as resident engineer.

Isaac Pratt ceased supervising the work on 30 May 1789, and Josiah Clowes was employed as engineer from early June, aided by John Gunnery.

The work included a stop lock in the tunnel where it joined Lord Dudley and Ward's basin, and a new straighter section and junction with the Birmingham Canal at the north end.

[9] With threats of competition from the proposed Stourbridge, Wolverhampton and Birmingham Junction Canal in May 1836, the company looked at ways in which passage through the tunnel could be improved.

They decided to enforce a by-law that required each boat to have a crew of two men to propel it through the tunnel, and a number of boatmen were called to account for non-compliance.

The Dudley Canal's superintendent, Thomas Brewin, suggested that cable haulage could resolve the issues, but the cost of the system at £6,000 was deemed to be too expensive.

[16] A second approach was made in 1845, and in the face of competition from the proposed Oxford, Worcester and Wolverhampton Railway, as well as the plans of the Birmingham Canal Navigations, they agreed to the merger on 8 October.

c. cclxix) was obtained to authorise the amalgamation, and the Dudley Tunnel became part of the Birmingham Canal Navigations system from 27 July 1846.

[19] By 1959, the tunnel was virtually disused, with no significant traffic having passed through it in the 1950s, and British Waterways announced plans to close it officially.

A number of protest groups organised cruises through the tunnel during 1960 in the hope of it being kept open,[2] but British Waterways at the time were intent on closing much of the canal network.

When the British Transport Commission presented their annual bill to Parliament in November 1961, it included proposals to close ten waterways immediately, of which the Dudley Canal and Tunnel were one.

[2] The following year, the viaduct that carried the Stourbridge to Wolverhampton railway line over the northern portal of the tunnel at Tipton was found to be structurally unsound.

However, when they got to Park Head, the three locks down to the No 2 Line had been damaged by British Waterways to prevent navigation, and while returning through the Dudley Tunnel, he found a message in a bottle.

He made contact with the writers, John Westwood and Cliff Sherwood, and plans to rescue the tunnel were soon drawn up.

[23] Smallshire wrote an 8-page article about the need to preserve the tunnel for the Inland Waterways Association, and there was widespread interest in the concept.

Afterwards, Fletcher warned that the group urgently needed to become official,[25] which resulted in the formation of the Dudley Canal Tunnel Preservation Society on 1 January 1964.

The Council called a public meeting, where the museum concept was greeted enthusiastically, and they started planning for the project.

Between June and December its members visited seven canals to discuss their future with local organisations, of which Dudley Tunnel was one.

[29] The fact that the tunnel remained open also meant that they did not have to spend millions of pounds on a storm water drainage system.

[2] In 1977 the Manpower Services Commission announced its Job Creation Scheme, through which they funded various projects which would create employment.

In August 1977, the Dudley Canal Trust celebrated the fact that 25,000 visitors had been carried into the tunnel by the trip boat since 1964, and on 1 October 1977, phase one of the museum opened,[31] Subsidence some 440 yards (400 m) from the south end of the tunnel resulted in it closing again in 1979, although boat trips into the caverns from the museum were not affected by this.

The cavern was formally opened to the public on 23 April 1985 by Neil MacFarlane MP and John Wilson, chairman of the MEB.

The work was completed in 1990, and the circular route was formally opened by councillor D H Sparkes, chairman of Dudley Economic Development Committee on 25 April.

[2] The Trust were given use of the disused Blowers Green Pumphouse at the foot of Park Head locks in 1996, and converted it to become offices and an education centre with workshops and stores attached.

The rock of Castle Hill into which the tunnel is dug, oolitic limestone, allows visitors to see trilobite fossils preserved within it.

Some fossils which were considered notable and were located close to the waterline, have been removed to prevent them from being eroded and attacked by visitors.