SteamIndex

Harry Jack. The first locomotive in Scotland. 110
For most countries, the actual date of its first railway engine is well-known, having been recorded at the time. Strangely, in the land of James Watt and William Murdoch, no-one seems to have thought that the very first use of a steam locomotive to pull a train was worthy of notice. No account of it has been found in contemporary newspapers, which is a long trawl, because even the actual year is uncertain.
That the first railway locomotive used in Scotland was on the Kilmarnock & Troon Railway, that the engine, The Duke, was built by George Stephenson for the Duke of Portland, was on six wheels, and that it was quickly given up because it was too heavy for the cast-iron plate-rails - all of this is mentioned in many books, but exactly when it happened is always left rather vague.
One witness of the engine's first run wrote about it some fifty years later in a book of reminiscences, but he said it happened "early in 1816", which is almost certainly too early. Perhaps, in his sixties and looking back to his early teens, he was uncertain of the actual year, so maybe he consulted the New Statistical Account of Ayrshire. This book contains an article written in 1839 by three Kilmarnock church ministers, who conclude rather casually: "We may mention that, in 1816, a locomotive engine, the first of the kind started in Scotland, was tried. It was intended to convey coal to Troon from the Duke of Portland's colliery, but from its defective construction and ill adaptation to flat rails, it only drew ten tons at the rate of five miles an hour. Since then no attempt has been made to introduce steam power."
Stephenson's patent for this design of engine was dated September 1816; Stephenson's biographer, Samuel Smiles gives the date of the Duke of Portland's engine as 1817; a French investigator Charles Dupin visited the railway in mid-1817 but apparently saw no locomotive there; Galloway in his 'Annals of Coal Mining' (1898) says the engine was "procured from Mr Stephenson" in 1819.
The surviving records of the Kilmarnock & Troon Railway contain one mention only. This is a complaint from a farmer, James Jack of Parkthorn (three miles from Troon) about fire damage caused by "the Cinders from a Steam Engine Waggon going along the Railway". The date of the entry in the minute-book is 16th October 1821.
A recurring legend says that the engine was fitted with wooden wheels and lasted on the K&T until 1848; another unsubstantiated story claimed it was sent to the Gloucester & Cheltenham Tramroad, where it worked until 1839. And as usual, the notoriously inaccurate Clement Stretton muddied the waters by illustrating the engine as a four-wheeler.
At least the engine's departure from the K&T is now definitely known. Recent research by Alan Brotchie in the archives of the Earl of Elgin revealed notes of correspondence in August and September 1824 with Alexander Guthrie, the Duke of Portland's coal overseer at Kilmarnock. This was about a "travelling engine" sent from Kilmarnock to the Earl of Elgin's railway at Charlestown in Fife, and purchased for £70. A letter to Guthrie dated 2nd October 1824 suggests that the engine arrived at Charlestown in September, but "I am sorry to say that from the small strength of our Rails we find it will not answer our waggonway." From 1825 it was used as a stationary pumping engine in a limestone quarry at Charlestown, and in 1830 it was moved to one of the Earl's coal pits, somewhere near Dunfermline. Working a pump at this rather vague location is the last authentic record of the first locomotive in Scotland.
Perhaps some contemporary note of its first appearance at Kilmarnock may yet turn up - I hope so, but this now seems unlikely.
Ref. A. W. Brotchie & H. Jack: Early Railways of West Fife. Stenlake Publishing Ltd, 2007.