Rheneas is a narrow gauge tank engine who works on the Skarloey Railway, and is nicknamed the "Gallant Old Engine" due to the fact that he single-handedly saved the railway from closure years ago. He has a twin named Dolgoch, and is Skarloey's brother.
Rheneas was built by Fletcher, Jennings & Co. in 1865, and arrived on the Skarloey Railway shortly afterwards. Contrary to Skarloey, Rheneas was a stern and thoughtful engine who did his work without hurry or fuss, and warned Skarloey to be careful when he had to pull the Directors' train, but Skarloey paid no attention to him. Rheneas was later chosen to pull the Directors' train after Skarloey was shut up in the shed, and the Directors were pleased with his performance.
After Skarloey returned from Whitehaven with a pair of trailing wheels and a cab, he began boasting to Rheneas about his new cab and suggested that he get one too, although Rheneas disagreed. The two began to argue with each-other, and their friendship came to an end when Skarloey called Rheneas a "stick-in-the-mud"; the quarrel was so bad that they refused to speak to each-other for several days. However, on a rainy Monday morning, Rheneas was called out to rescue Skarloey when he derailed at a landslide near the tunnel. Rheneas initially refused, but when he was reminded of the Quarrymen and Mr. Bobbie, he hurried to the rescue. After rescuing him, Rheneas and Skarloey apologized to each-other and reconciled their friendship. (RWS; Very Old Engines)
Rheneas never returned to Whitehaven for any repairs, and any maintenance that was needed, including the addition of a cab, was done at the Skarloey Railway's workshop. In 1937, and again in 1943, he was overhauled in the North Western Railway's Works at Crovan's Gate. When Rheneas returned from his second overhaul in 1943, he became the main engine on the railway, as Skarloey had been laid aside. (Book; The Island of Sodor: Its People, History and Railways)
Rheneas kept the railway going through a very lean period in the 1940s. By 1950, Skarloey was in a bad state and needed repairs, so Rheneas took over his duties. While taking a passenger train back home on a bleak, rainy day, Rheneas came to a stop on the loneliest part of the line when his valve gear jammed. His crew managed to loosen his rods, and he weakly made it to the next station, saving the railway from closure. (RWS; Gallant Old Engine)
When Sir Handel and Peter Sam arrived on the Skarloey Railway, Rheneas was sent to England to undergo an extensive overhaul. (RWS; Four Little Engines) While he was being repaired, he was reunited with his twin, Dolgoch, who was being repaired in the same workshop. However, money was short, and Rheneas' overhaul was not completed until 1961. (Book; The Island of Sodor: Its People, History and Railways) He returned to the Skarloey Railway that same year. (RWS; Gallant Old Engine)
For his and Skarloey's 100th birthday, Rheneas pulled the coaches up to the new loop line, and his passengers all wore clothing reminiscent to 1865. After the Duke of Sodor opened the loop line, Rheneas gave a speech, and told everyone about the Talyllyn Railway and his twin, Dolgoch. (RWS; Very Old Engines)