There was an upsurge in commercial traffic during the First World War, when components for the construction of mines were shipped through the canal on their way from America to "U.S. Naval Base 18” (Muirtown Basin, Inverness), and fishing boats used it to avoid possible enemy action on the longer route around the north of Scotland. During this period there was 24-hour operation, facilitated by buoyage and lighting throughout its length. Ownership passed to the Ministry of Transport in 1920, and then to British Waterways in 1962. Improvements were made, with the locks being mechanised between 1964 and 1969. By 1990, the canal was in obvious need of restoration, with lock walls bulging, and it was estimated that repairs would cost £60 million. With no prospect of the Government funding this, British Waterways devised a repair plan, and between 1995 and 2005, sections of the canal were drained each winter. Stainless steel rods were used to tie the double-skinned lock walls together, and over 25,000 tonnes of grout were injected into the lock structures. All of the lock gates were replaced, and the result was a canal whose structures were probably in a better condition than they had ever been.