WILLIAM FLETCHER'S COMPARISON OF British and American Engines


| September/October 1995



735 Riddle Road Cincinnati, Ohio 45220

In 1904, William Fletcher published English and American Steam Carriages and Traction Engines. A master mechanical engineer, Fletcher designed engines at various times for the British companies of Clayton & Shuttleworth and Ransomes, Sims, and Jefferies. His 428-page book (published by Longmans, Green, and Company with offices in London and New York) offers insight into how a British designer viewed American traction engines.

Fletcher believed that English engines of the late 1800s and early 1900s were built slightly heavier than most of their American counterparts. British designers wanted their traction engines to be perceived as 'all purpose 'good for hauling over relatively long distances and for belt work. Also, English threshing machines were notoriously bulky; only a sturdy engine could pull such threshers over muddy country lanes.

In Fletcher's day, the thickness of the boiler plate of the typical English engine surpassed that of an average American engine. Most of the plate used in British boilers was between seven-sixteenths and one-half of an inch thick, and the plate in those portions of the firebox exposed to the greatest heat might be even thicker. As Fletcher reported, the boiler itself was often shorter and slightly wider in diameter than was customary in an American engine. This factor might help to account for Fletcher's assumption that British engines were 'quick steamers.' Like the boilers, English fireboxes tended to be short and not too deep. The fireman (or stoker) had to hope for coal (and coke) of a high quality! In most British makes of engines, fireboxes used a sliding door, not the hinged doors common on American fireboxes.

The diameter' of the tubes in British boilers usually measured one-fourth of an inch wider than that of tubes in the average American boiler. With larger tubes, fewer were needed than was normal among American makes. According to Fletcher, British designers did not want a great many tubes because they wished to provide as much steam space above the water line as practicable. The proportionately lower water level in an English boiler might explain the property of getting steam up quickly.

British designers often employed cross-compound cylinders for plow engines, road locomotives, rollers, and showman's engines. Single-cylinder engines served agricultural and general purposes, but double-simple and tandem-compound cylinders were as rare as hen's teeth. Fletcher argued that a double-simple arrangement wasted steam. For their cross-compound cylinders, English designers preferred center-cranked engines, as a glance through Floyd Clymer's Album of Historical Steam Traction Engines will corroborate. Most British cylinders rested within a large, sturdy jacket. As steam direct from the boiler rose to fill this jacket, and as it was this steam which entered the steamchests, one could say that this jacket replaced the steamdome. Indeed, English engines seldom were equipped with a dome, while American boilers almost invariably had one. Although certain English designers placed the steamchests on the sides, thereby making it easier to gain access to the valves, most located the steamchests on top of the cylinders and well within the large jacket. This arrangement served to improve the engine's efficiency.