the 2009 season, boats have been allowed to travel through the tunnel under their own power with an experienced chaperone on board to guide its passage, followed by a service vehicle through one of the parallel disused railway tunnels. Railway tunnels Three railway tunnels run parallel to each other and the canal tunnel. Through them runs the Huddersfield line. They are level for the whole length, which had the operational benefit of providing the only section of level track on the line where water troughs could be installed to provide steam locomotives with water without requiring the train to stop. Both the single-track bores have ventilation shafts at Cote, Flint and Pule Hill and the double-track tunnel is ventilated via three shafts at Brunn Clough, Redbrook and Flint. Drainage adits interlink with one another, including the canal tunnel, into which water is discharged. In 1846, work commenced on a railway tunnel for the Huddersfield & Manchester Railway. It ran parallel to, and to the south of, the canal tunnel at a slightly higher level. From the canal tunnel, thirteen adits were driven to facilitate excavating the railway tunnel. The railway company had bought the canal company to provide access. Boats transferred excavated spoil and moved construction materials. Canal access increased the rate of construction, which took a little over two years; in comparison, the Woodhead Tunnel, which was slightly shorter, took seven years to build despite the work being done by the same contractor, Thomas Nicholson. The tunnel was driven and lined by up to 1,953 navvies working 36 faces. The tunnel advanced at up to per week. Nine men died during its construction. In 1848, the central single-track tunnel was completed by the London and North Western Railway (L&NWR), who had acquired the Huddersfield & Manchester Railway midway through its construction. Costing £201,608, the tunnel is long. When opened, trains were accompanied through the tunnel by a pilot man or pilot engine and their re-emergence was communicated between signal boxes situated at either end by a telegraph system devised by Henry Highton. The 1848 tunnel soon became a bottleneck for rail traffic between Huddersfield and Manchester. Even before its completion, plans were in consideration for a second tunnel alongside it. When the economic case became clear, Thomas Nelson, who built the first railway tunnel, was awarded the contract. As with the first tunnel, the canal tunnel was linked to