and Wick is the longest between any two adjacent stations on the line, although three other stations existed along this stretch until 1960. Wick is the nearest station to Wick Airport as well as to the village of John o' Groats (approximately to the north) at the northeastern tip of mainland Britain, which is linked to the town by a bus service operated by Stagecoach Highlands. Infrastructure The full line between and (excluding the Thurso branch) is long; the branch has a length of . The whole line is unelectrified. Despite its considerable length and passing through the mostly mountainous Scottish Highlands, there are no tunnels on the line. The line is almost entirely single-track, but there are 10 double-track passing loops along the route, which allow trains to pass each other: these are at , , , , , , , , and . The loops at Rogart and Brora are not timetabled to be the passing place for any scheduled passenger services, but they can be used as such during major disruption on the line. The whole line north of the former Clunes station (about west of Inverness), together with the Kyle of Lochalsh line, are signalled using the Radio Electronic Token Block system, which is very cost-effective in both implementation and maintenance, but significantly limits the capacity of the lines. History Pre-Nationalisation The line was built in several stages: Inverness and Ross-shire Railway - Opened 11 June 1862 between Inverness and Ardgay Sutherland Railway - Opened 13 April 1868 between Ardgay and Golspie Duke of Sutherland's Railway - Opened 1 November 1870 between Golspie and Helmsdale Sutherland and Caithness Railway - Opened 28 July 1874 between Helmsdale and Wick / Thurso Much of the work was done by the Inverness-based Highland Railway company or, when completed, taken over by that company. In 1923 the Highland Railway was grouped into the London, Midland and Scottish Railway, under the Railways Act of 1921. Like railway lines generally in Britain, the line was not a product of any strategic plan, but was an ad hoc development, facilitated by Private Acts of Parliament (which were themselves a significant expense for developers) and dependent on cooperation between companies and individuals, each with their own private vested interests. The line became strategically important during World War I and World War II as part of a supply route for Scapa Flow, Orkney. That the