Mindsigh

Cugnot’s steam tractor – Fardier a Vapeur

Posted by jerry on June 25th, 2006 — Posted in History, Journal, Steam, Technology

One of the little-known museum gems in Paris is the Musee des Arts et Metiers – the museum of technology. Among the amazing objects there is Nicolas Cugnot’s steam tractor – the Fardier a vapeur. This is the first steam propelled vehicle – from which the development of the modern automobile began.

Back in 1769, when Captain Cook was preparing for his voyage to Australia, a French military engineer was considering the merits of using steam to propel a vehicle. With the backing of the Minister for War, the Duke of Choiseul, Nicolas Joseph Cugnot (1725-1804) developed a prototype steam tractor for towing artillery without horses. The prototype was built under Cugnot’s direction by Army mechanic Brezin at the Paris Arsenal. The first protoype showed some limited promise, and he went on to build a second vehicle in 1770. His idea was to use a three-wheeled cart, with a high-pressure boiler placed in front of the driving wheel, and a two-cylinder piston engine to push on a notched disc each side of the wheel. The whole driving assembly was mounted so it could pivot on a vertical axis for steering – with a steering lock of about 15-20 degrees in either direction. It seems very front-heavy, but it was designed to tow a heavy artillery piece.

The machine has a reverse gear and could move its five-tonne load at up to 4 km/h. It was only partially successful, however. The fire-box was small, and the machine could sustain steam for only about 15 minutes before it ran out of steam pressure. And the lack of brakes and and slow steering (by geared rack and pinion) made the machine unwieldy. On an early test run it failed to make a sufficiently sharp turn and crashed into a stone wall, and the project was scrapped – after the first motor vehicle accident in history – in 1771.

The test vehicle was long thought to have been destroyed during the French Revolution, until it was discovered in Napoleon’s time. It has been preserved in the Musee des Arts et Metiers since 1800.

I am happy to report that the machine is still in an excellent state of preservation, and the workmanship of the mechanic, Brezin, was very professional in its approach. The two single-acting cylinders are 13 inches in diameter, and the structure is robustly constructed on massive timber beams. Cugnot himself received a pension of 600 francs, which was revoked in 1789, forcing Cugnot into exile in Brussels. He was brought back to France and his pension reinstated by Napoleon shortly before he died in 1804 at the age of 79 years.

The museum website has an excellent video presentation on how the engine worked

The vehicle’s scale is impressive as you can see in the following photos I took 2 weeks ago.

Cugnot’s steam carriage – the Fardier a Vapeur 1770

Cugnot’s boiler assembly

Cugnot’s steam wagon – left view

Drive gear on Cugnot’s steam carriage

Cugnot’s engine valve gear – detail

Cugnot’s drive train

This picture is included just to provide a sense of scale to Cugnot’s steam wagon

Cheers
Jerry

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