by 1 June 1778. It was later extended to Castle Mill, where a basin was constructed. The Dudley Canal and Stourbridge Canal then looked at an extension northwards from Dudley, to join the Birmingham Canal. This would involve a long tunnel, and Lord Dudley and Ward agreed to sell his branch canal and tunnel to the company. The enterprise was authorised by another Act of Parliament, obtained in July 1785, which was steered through the parliamentary process by Lord Dudley and Ward. He was thanked for his efforts, but the company argued that he received sufficient benefit from the convenience of the Dudley Canal and the favourable tolls awarded to him, that payment for his branch canal should not be made, and it never was. The act authorised the company to build five locks to the north of their existing canal, to reach Parkhead, and a long tunnel to link up with Lord Dudley and Ward's Castle Mill Basin. The route was surveyed by John Snape and John Bull, and was checked by Thomas Dadford. He then became the consulting engineer for the project, while Abraham Lees supervised the day-to-day work. In September 1785, the company announced that the tunnel would be wide, the water would be deep, and there would be headroom of . John Pinkerton, one of a family of respected canal contractors, was awarded the contract for construction of the tunnel, but it was the first time he had worked on a tunnel, and he hit problems, first with the quality of the ground he was trying to excavate, and also with the large volumes of groundwater that he encountered. There were complaints about his lack of progress and the poor quality of the brick lining, resulting in him being dismissed in 1787. He had to pay £2,000, which was an amount agreed as a bond when the contract was awarded, after which there was an interlude, while arguments were resolved. The tunnelling was then supervised by Isaac Pratt, one of the Stourbridge and Dudley committee members, with Abraham Lees continuing as resident engineer. In May 1789, there were more difficulties, when it was realised that the tunnel had deviated from its proper line in several places, and that progress was slow. Isaac Pratt ceased supervising the work on 30 May 1789, and Josiah Clowes was employed as engineer from early June, aided by John Gunnery. Gunnery