limited load capacity and the lack of a towpath damaged the competitiveness of the whole canal when compared to the rival Rochdale Canal, which was only a few miles to the north and competed with the Huddersfield Canal for business. Although there were widened passing places in the tunnel for handling bi-directional traffic, intense competition between boat crews was a hindrance and two-way operation in the tunnel was impractical. The canal company introduced one-way working, for which one end of the tunnel was closed by a locked chain to prevent access unless authorised. A similar arrangement remains in use. In 1846, the Huddersfield Narrow Canal was purchased by the Huddersfield & Manchester Railway. The canal tunnel was used during the construction of the first railway tunnel and no shafts were needed. The canal provided an easy means of removing the excavated spoil. When the railway tunnel was completed, several cross passages were retained. The last commercial boat passed through the tunnel in 1921 and the canal was closed to traffic in 1944 when maintenance ended and the tunnel fell into a state of disrepair. The last boat to pass through the tunnel before its restoration was the Rolt/Aickman expedition in the Ailsa Craig in 1948. Writing in 1948, L. T. C. Rolt described the journey as taking two hours, during which the speed was kept very low to avoid damage to the boat. The canal had become obstructed in several places on both sides of the Pennines and the tunnel, which had become unsafe, was closed by large iron gates at each end. A local newspaper described a trip organised by the Railway and Canal Historical Society during 1961, which was held to commemorate 150 years since the canal's opening. The expedition used a single narrowboat, which departed Marsden around 11 a.m. and emerged from the Diggle portal around 1 p.m. Restoration The canal and tunnel benefitted from a £5 million restoration project to re-open the canal. Several rock-lined parts of the tunnel were stabilised by rock bolts where possible and concrete was used to stabilise the rock face where this was impractical. In May 2001, the tunnel was re-opened to traffic. Most modern canal boats are diesel-powered and it was considered unsafe for boaters to navigate the tunnel using diesel power because of its length and the lack of ventilation, so electric tug boats haul the narrowboats through. Since