men and materials to be moved to the work sites, as there was no road access. The railway from the factory eastwards to Loch Treig was known as the Upper Works Railway. There were some challenges to constructing a railway to serve the access points for the tunnel. Base Camp was at an altitude of , and Adit 10, the first stopping point above Fort William and from it was at . This would have required an average gradient of 1 in 22, which was not suitable for an adhesion railway. The railway was laid at an average gradient of 1 in 35 to a point from Base Camp, where a junction served a branch that ran back along the hillside to the adit. There were several lengths of 1 in 30 within the first , and some stretches of 1 in 25. Further along, the railway crossed some peat bogs, and the track was laid on fascines made of brushwood, which led to the track being quite flexible. Three teams of men were employed on the construction, one working upwards from Base Camp, a second working from Central in both directions, and the third working from Fersit in both directions. The teams consisted of six to ten men, working with pickaxes and shovels, and they were able to level of the formation each day. The Pier Railway was always intended as a permanent feature, and was laid with heavy duty rails, weighing . However, its route was not ideal, as it ran through some land where it was intended to build the village of Inverlochy for the workers. The railway was reconstructed along a new route, which was slightly longer than the original, at , and crossed the West Highland Railway and the A82 road from Fort WIlliam to Inverness on plate grider bridges. The earlier railway had crossed the A82 road at a level crossing. The Upper Works Railway was laid with lighter rails, weighing , as it was intended to be a temporary feature. Large teams of men were employed to build trestle bridges using local timber over the many streams which crossed the path of the railway. Two locations were unsuitable for such bridges, and Bridge 15 over the Allt Leachdach between Central and Adit 5 consisted of a steel span, supported by concrete pillars at either side of the ravine. Bridge 27 near Adit 6