m) Wast Hills Tunnel was open and the canal was trading to Hopwood. In 1807 the canal reached Tardebigge without the use of locks. From Worcester Bar to Tardebigge top lock, the canal is at the 453 ft Birmingham Level. The cost of building locks was too great so the 56 locks down to Worcester were built to the narrow specification, with the final two locks connecting to the Severn in Worcester being to allow river craft access to Diglis Basin. The final 16 miles (26 km) was opened in December 1815. Plans to construct basins at Lowesmoor and Diglis were carried out eventually. The Dudley Canal Line No 2 was built through the Lapal Tunnel to meet the canal at Selly Oak in 1798. After repeated collapses, the tunnel was finally abandoned in 1917 leaving a short stretch navigable between Selly Oak and a brick works at California until 1953, after which it was drained and filled in. A campaign group, The Lapal Canal Trust, is working to restore it, with a diversion around the tunnel. A major user of the canal was the Cadbury chocolate factories at Bournville and Blackpole, Worcester. Birmingham terminus For twenty years direct connection to the Birmingham Canal Navigations (BCN) was prevented by the Worcester Bar, a physical barrier at Gas Street Basin, Birmingham designed so that the BCN would not lose water to the Worcester and Birmingham. Cargoes had to be laboriously manhandled between boats on either side. In 1815 an Act allowed the creation of a stop lock and the bar was breached. The Worcester and Birmingham raised their water level by six inches to minimise water loss and today the two pairs of lock gates have been removed. There were separate toll offices either side of the bar for the two canal companies. The bar still exists, with boats moored to both sides of it. The commercial terminus in Birmingham was Worcester Wharf, a large complex extending from the bar along Bridge Street, Gas Street and Granville Street. Part of it now forms a water front to The Mailbox shopping and residential complex. Birmingham West Suburban Railway After the development of the new Birmingham New Street, a group of local business men noticed the resultant need for additional railway capacity south, through what were the under developed suburbs of south Birmingham and villages of northern Worcestershire. They therefore proposed development of