Brooks, Paul D., Cugnot’s 1769 steam vehicle – pioneering new technologies, Transactions of the 2nd International Early Engines Conference, Volume 2, IEEC & ISSES, 2023 [ISBN: 9781872986258/ISSN: ISSES, Stationary Power v.25 0960-0663], pp.67-76 doi:10.54267/ieec2-2-06
Cugnot’s 1769 steam vehicle was not only the first self-powered vehicle, but also appears to be the first non-condensing pressure only steam engine constructed. It is probably the only engine built using Leupold’s valve gear, and is remarkable in having a two-cylinder engine with forward and reverse rotary motion using a ratchet system. The original may be the only surviving ratchet rotary system. It is also the first vehicle to have front wheel drive with the engine ahead of the front axle to put more weight on the drive wheel, and the first to have rack and pinion steering. It was probably not developed as it was too heavy for the roads of the time. As a military project it was not well publicised and therefore does not appear to have had any effect on the subsequent development of steam engines. The original’s boiler does not have a pressure safety valve or drain cocks and does not make much sense even for the time. It is speculated that this was not the final boiler used for trials but an earlier boiler.