The marker lights in the former headcode box give an indication as to how dark it is, as the Pathfinder Tours 1Z27 06:40 Swindon to Inverness 'Orcadian' railtour passes Slochd on 16 June 2006. At not far short of 22:00, even in Scotland it was virtually dark, necessitating an exposure of 1/500sec f2.5 at ISO1600. In the previous couple of hours the 50s had tackled two of the most fearsome gradients on the national network, the over six miles of continuous 1 in 70 to Drumochter Summit, followed by the 1 in 60 and 1in 70 climb to Slochd Summit.