Aveling & Porter Ltd, Rochester

Lowe estimates that about 130 locomotives were constructed by a firm which is extremely well-known for its traction engines and steam rollers. The firm was founded by Thomas Aveling as an agricultural engineering business. It began by repairing portable engines, and by converting new portable engines into road locomotives by substituting a revolving road-shaft for the ordinary axle, wider and stronger wheels, and the addition of a pitch-chain to transmit the power from the crankshaft. The earlier engines were without steering gear, a single horse in shafts serving to steer them. The first patent for pitch-chain driving-gear was taken out in 1859, the object being to take up slack due to chain wear, without affecting the pitch-line of the gearing. The first traction engines were manufactured in 1861. In 1860 he had exhibited a self-moving engine at the Royal Agricultural Society's Show at Canterbury; In 1861, at the Leeds Show of the Society, he exhibited for the first time an engine entirely of his own manufacture. It was at this period that he was joined by Porter, and by Aveling's son, Thomas Lake Aveling In 1864 the traction engine type was modified to run on rails and construction of this type continued until 1926. The firm always aimed at simplicity and strength. Two cylinders were not used if one would do. By placing the crankshaft aft, and the cylinder forward, he secured two advantages: first dry steam when most wanted, i.e. when pulling up hill; and secondly, the fly-wheel within reach of the driver, should he carelessly let the crank stop on the centre. Seeing that one of the most important elements of success in road locomotives was a supply of dry steam to the cylinder, he arranged a steam-jacket in such a way as to serve for a dome; and in later years he substituted wrought-iron brackets (formed by continuing upwards and backwards the side plates of the firebox) for the cumbrous cast-iron brackets previously in use, thereby greatly increasing the strength of the engines and their immunity from breakdowns. Aveling introduced steam for military use: "steam sappers" were adopted by the Artillery and Royal Engineers Two chain driven locomotives were supplied to the Duke of Buckingham for use on the Wootton Tramway: one is preserved by London Transport. In association with Alfred Grieg the Aveling-Greig Street Tram Engine was marketed. . In Locomotive Mag1927, 33, 130 list: British locomotive manufacturers, past and present. See also Andrew Neale. Traction engine locomotives.Archive, 2015 (87) 2-21 and Macnair From road unto rail Backtrack, 2020, 34, 164..