First, stop giggling. Steam-powered automobiles could very easily have beaten out their gasoline-powered
bretheren if history had been slightly kinder to them.
Comparison of engine cycles
Internal combustion engine
- Intake: fuel-air mixture is drawn into the cylinder above the piston.
- Compression: the mixture is compressed by the piston's upward motion and ignited.
- Ignition: the exploding mixture forces the piston downward, driving the crankshaft.
- Exhaust: the piston moves upward, expelling unburned and partially burnt exhaust.
- Expansion: similar to ignition, the steam expands, pushing the piston, driving the crankshaft.
- Exhaust: piston moves back, expelling the steam.
Major problems of steam-powered automobiles
- Slow starting
- Freezing problems
- Boiler explosions
- Fuel efficiency
The slow starting and freezing problems can be dealt with by substituting a new liquid for water or adding soluble
oils to the water. The limiting factor of fuel efficiency is no longer running out of water, but rather running out of actual fuel for heating the boiler, however, nearly any inflammable
material can be used, from deisel
to paint thinner
. Boiler explosions are dealt with both by building the boiler out of stronger materials, and by using flash boilers
that only create steam when required.
A historical look
The first steam-powered automobile was a three-wheeled truck built by the French army engineer Nicholas Joseph Cugnot in 1769. It could run at about 3 mph, and carry 3.5 tons. Two of these experimental vehicles were constructed, and one of them is still on display in Paris. The engine ran on two cylinders, and was extremely fuel (that is to say, water) inefficient. Cugnot's project was abandoned after its second trial run, in which it crashed into a wall and flipped over.
Cugnot's machine was the exception to what quickly became the rule of steam-powered vehicles: trains. England actually imposed heavy fees for anyone who wanted to put a steam engine on a carriage. Some English inventors decided it was worth the extra trouble, such as Richard Trevithick, who constructed his first vehicle in 1801, which caught fire and burned its shed down after its maiden voyage. Trevithick continued to build steam-powered cars, one of which ultimately claimed his life in London when he crashed it through a fence.
By the 1820's, large steam-powered carriages were bussing passengers from London to nearby outlying towns. These early busses, which ran at around 10 mph, could support a boiler pressure of around 200 psi, which was four times the capacity of the average boiler of the day. W. H. James built a bus in the 1930's that ran on a four cylinder engine, with each cylinder powering one wheel, and featured luxuries like shocks and a gear shift with three separate gears. Unfortunately, railway investors lobbied against Parliament's repeal of steam carriage fees, so there was never a real concentrated effort to develop the carriages.
Another Frenchman to work on steam cars was Leon Serpollet, who is notable for actually developing a steam engine specifically for automotive purposes, instead of simply lifting the technology from trains. He constructed a flash boiler that would produce steam only as it was needed, thus preventing boiler explosions, while still allowing very high pressures. He heated his water with paraffin instead of wood or coke. One of his cars set a land speed record in 1902, 75.06 mph.
Probably the most famous American steam car makers were the Stanley twins, Francis E. Stanley and Freelan O. Stanley. The "Stanley Steamer," as their vehicles were known, became popular among certain circles for their speed, handling, and relative quiet compared to internal combustion engines. Unfortunately, the Stanley twins were hardly Henry Fords when it came to marketing. The potential buyer had to go through a personal interview session with the twins to see if he had the "proper personality" for a Stanley Steamer. Also, since they were only producing about 600 cars per year, they couldn't compete with Ford's factories and promises of "a car in every family." In 1906, a Stanley Rocket driven by Stanley mechanic Fred Marriott set a world speed record of 127.66 mph, and in 1907, and reportedly reached a speed of 197 mph before crashing and seriously injuring Marriott.