Mallaig, the port for the island of Skye, was one of the last significant towns in the United Kingdom to become part of the railway network. The North British Railway’s route linking Glasgow with Fort William was completed in 1894, and the 67.5 km extension to Mallaig in 1901.
The principal engineering feature of the line is the 384 m long, 31 m high, 21-arch concrete viaduct that crosses the River Finnan where it cascades through a rocky and desolate glen into Loch Shiel. The viaduct was built by Sir Robert McAlpine & Sons, by that time the leading civil engineering contracting firm in Scotland, whose founder, Sir Robert McAlpine (1847-1934), had strongly favoured the use of concrete from the 1870s, and was sometimes called ‘Concrete Bob’. A particular reason for the choice of concrete for the viaduct was that the building of cuttings and tunnels on the Mallaig Extension yielded hard rock that could not be dressed for use as masonry but was a suitable aggregate, when crushed and graded, for use in concrete. The viaduct is a mass concrete structure, with no reinforcing, the concrete having been poured in to timber form-work.
A museum in the chalet-style railway station at Glenfinnan has displays relating to the construction of the viaduct, as well as to other aspects of railway and local history, and temporary displays of work by leading railway photographers. Visitors are able to work single-line tablet-exchange apparatus of the kind once used on the line, to take meals in a Mark I dining car built by British Railways in the 1950s, and to stay the night in a sleeping car of the same vintage.
A regular service of diesel trains, usually four per day, calls at the station, and in the summer months a stop long enough to enable travellers to inspect the viaduct and see the museum is made there by the Jacobite steam train from Fort William to Mallaig, which is operated by West Coast Railways.