Portpatrick, on the western side of the Rinns,[note 1] had long served as a port for a short sea route from Donaghadee in Northern Ireland.

Also the development of more attractive alternative routes, in particular from Holyhead to Kingstown, (renamed Dún Laoghaire) led to a loss of commitment to Portpatrick.

[4] This siding expanded into a large yard of ten parallel roads, ultimately 61⁄4 miles long, curved round to the shore of the loch.

"[5] The preparations for the Normandy landings took the focus of activity to the south of England, and Cairnryan was for the time being reduced to a care and maintenance status.

[6] At the end of June 1942, King George VI and Queen Elizabeth paid a visit to Northern Ireland,[7] and it was arranged that they would travel via the Cairnryan Military Railway and the port.

[8] After the end of World War II, the facility was used to load superfluous ammunition, brought to the port by rail, onto army landing craft for disposal at sea - a hazardous task, which took the lives of several at the port (including on one occasion eight young servicemen killed on the North Deep Water Wharf when accidentally mishandling a case of fuses),[9] while the long-term and wider risks of such dumping have only later become more evident.

Smith describes the railway operation on the military line: They brought these gas shells in standard trains of 32 wagons.

[10]At the end of the war, the Atlantic U-boat fleet surrendered in Loch Ryan and was anchored in the port before being towed to the North Channel and scuttled.

The remaining pier is in a state of disrepair and fenced off to the public after partially collapsing in the 1990s when it was being used to load stone from the nearby Croach Farm quarry in Cairnryan.

As the importance of rail passenger connections further declined, Stena Line also transferred to Cairnryan opening a new terminal at Old House Point in 2011.

There is also a coach link between here and Ayr railway station going up the Ayrshire Coast Line, by a company named Dodds of Troon.