Drawing produced by John Llewellin of a Tram Engine designed by Richard Trevithick

Drawing, Tram Engine. 4 3/4 Inches Dia. of Cylinder. 3 Feet Stroke / John Llewellyn. 1803 Dec. Line drawing, scale 1 : 12, of a Trevithick locomotive, credited to John Llewellyn. It is believed to be a design for a 3-foot gauge locomotive for Coalbrookdale. Drawing apparently presented to Patent Office in 1862 by William Menelaus to whom it was given by John Llewellyn's nephew, William. See article 'Trevithick's First Rail Locomotive' by W.W. Mason in Trans. of the Newcomen Soc., XII 1931-32. See also The Penydarren Locomotive / S. Owen-Jones, 1981.

The subject of the drawing was initially thought to be Richard Trevithick's locomotive for the Pen-Y-Darren tramway, the first recorded railway steam locomotive and subject to a bet between Samuel Homfray and Richard Crawshay. This was later ruled out as the locomotive in the drawing does not match the known dimensions of the Pen-Y-Darren locomotive. It has been suggested that the locomotive in the drawing could have been built at Coalbrookdale or a different quarry tramway in South Wales.