It continued to expand, reaching Wick and Thurso in the north and Kyle of Lochalsh in the west, eventually serving the counties of Caithness, Sutherland, Ross & Cromarty, Inverness, Perth, Nairn, Moray and Banff.

[2] During the First World War the British Navy's base at Scapa Flow, in the Orkney Islands, was serviced from Scrabster Harbour near Thurso.

The Highland Railway provided transport, including a daily Jellicoe Express passenger special, which ran between London and Thurso in about 22 hours.

Construction eventually began in November 1852, albeit only 39 miles (63 km) to Huntly, and this line was officially opened on 19 September 1854.

[5] [6] The line opened ceremonially on 5 November 1855 when a train of thirty vehicles, mainly goods wagons fitted with seats, made a return journey.

[a] Initially three trains a day ran between Inverness and Nairn, horse-drawn coaches providing a link to Keith and thereby Aberdeen via the Great North of Scotland Railway.

The GNoSR offered £40,000 towards a bridge and the Inverness and Aberdeen Junction Railway (IAJR) was given authority for a line from Nairn and Keith in July 1856.

A temporary station at Dalvey, west of the River Findhorn, opened on 22 December 1857, to close when the line extended to Elgin on 25 March 1858.

[17] Between Forres and Elgin two branches opened, the first being from Kinloss to Findhorn; 3 miles (4.8 km) long this operated independently from 18 April 1860 before being taken over by the IAJR in 1862.

Although a similar route had been rejected in 1845 because of the high altitudes and speed gradients, there had been sufficient advance in locomotive design to satisfy the fears of the parliamentary committee, and authority was given in 1861.

The route followed the Kyle of Sutherland inland for 3 miles, before crossing over to the north shore with the five masonry arches and 230 feet (70 m) girder span of Invershin Viaduct.

[40] The 3rd Duke of Sutherland planned an extension of the line 17 miles (27 km) from Golspie to Helmsdale, passing Dunrobin Castle, his family seat.

Two trains a day ran until 19 June 1871, when the line was connected up with the Sutherland Railway at Golspie and the Highland extended its services to Helmsdale.

[45] Only certain routes are practicable in the Highlands due to the terrain, but from Dingwall it was possible to reach Kyle of Lochalsh on the west coast, opposite the Isle of Skye.

Permission had been granted for the 15+3⁄4 miles (25.3 km) to reach Rosemarkie, and the line to Fortrose was opened on 1 February 1894, and work did not start on the planned extension.

The Highland Railway route was chosen, but the Great North won a concession that goods and passengers that could be exchanged at any junction with through bookings and with services conveniently arranged.

This was refused, but in 1886 the Great North and Highland railways came to an agreement to pool receipts from the stations between Grange and Elgin and refer any disputes to an arbiter.

[65] With no judgement by 1897, the Great North again prepared to apply again for running powers over the Highland to Inverness, this time agreeing to double track the line, but the commissioners published their finding before the bill was submitted to Parliament.

[78] The Great Glen is a natural route that runs south west from Inverness to Fort William and is used by the Caledonian Canal, and more recently the A82 road.

[79] The Highland, concerned about competition from a shorter route, argued that there was insufficient traffic travelling south from Inverness for two lines, and the proposal was rejected by Parliament.

Permission was given and the North British and West Highland Railways both agreed not to sponsor any line through the Great Glen for ten years.

[90] The Navy established a base at Scapa Flow, in Orkney, and this was serviced from Scrabster Harbour, 2 miles (3.2 km) from the Highland station at Thurso.

[96] The railways were in a poor state after the war, costs having increased, with higher wages, the introduction of an eight-hour day and the price of coal having risen.

[117] Currently[update], the Highland Railway's main lines out of Inverness are used by ScotRail services to Perth, Keith, Kyle of Lochalsh, and Wick and Thurso.

[123] The Far North Line is served by four trains a day from Inverness to Wick, via Thurso,[e] taking about 4+1⁄4 hours, supplemented by four services to Invergordon, Tain or Ardgay.

[37] The Inverness & Nairn opened in 1855 with two 2-2-2 locomotives with four wheeled tenders, built by Hawthorns of Leith, with a weather board to protect the engine men.

[150] Drummond changed the locomotive livery soon after joining the company, removing the red lining, edging instead in white, and adding 'HR' on the tenders or tanks and front buffer beams.

A mail van made in 1858 for the Inverness to Keith route survived until 1903; this was 20 feet 10 inches (6.35 m) long, and fitted with Newall's chain brake.

[165] After Drummond became locomotive supervisor at Lochgorm in 1896 the older carriages were replaced by bogie stock that had access to a toilet from both third and first class accommodation, gas lighting and steam heating.

The livery reverted to green in 1903, although the sleeping carriages that which replaced the Pullmans and main-line excursion trains were built in varnished teak.