Skarloey was built at Fletcher, Jennings & Co. in Whitehaven alongside his twin Talyllyn. While Talyllyn was destined for a railway in Wales, Skarloey was destined to work on Sodor, and arrived on a ship at Kirk Ronan Harbour in 1865. He was transported by the S&M's Neil to Crovan's Gate, where he worked for a few months on his own before being joined by Rheneas.
Skarloey is the wise sage of the Skarloey Railway and is an old, faithful little engine. Although once full of enthusiasm and his own ideas in his youth, Skarloey is now one of the oldest engines on the Island. He is a calm-natured, quaint, and mature engine and may often try to guide or watch over less experienced narrow gauge engines in his firm but fair and friendly manner. He acts kindly to engines and passengers alike and always enjoys a gentle, smooth journey through the woods by the lakeside and stopping at all the gates and stiles he remembers so well. He is considered, and often acts like, the leader of the narrow gauge engines.
Skarloey is painted in the Railway's once-standard livery of scarlet red with blue lining and brass fittings. He has brass name and number plates with red backgrounds on the sides of his saddle tank and coal bunkers, respectively. Up until 1985, his name was painted on his saddle tank in yellow.