Before long, defects in some of the materials used became apparent, and part of Corpach double lock collapsed in 1843. This led to a decision to close the canal to allow repairs to be carried out, and the depth was increased to at the same time. The work was designed by Telford's associate James Walker, carried out by Jackson and Bean of Aston, Birmingham and completed between 1843 and 1847 at a cost of £136,089. However, not all of the traffic expected to return to using the canal did so. Commercially, the venture was not a success, but the dramatic scenery through which it passes led to it becoming a tourist attraction. Queen Victoria took a trip along it in 1873, and the publicity surrounding the trip resulted in a large increase in visitors to the region and the canal. The arrival of the railways at Fort William, Fort Augustus and Inverness did little to harm the canal, as trains were scheduled to connect with steamboat services.