Steam powered cars

Great Debates
1

I know in the past there were steam powered cars, but that they pretty much lost out to IC cars early in the 1920’s. My question is, could you build one using modern materials and technology that would be safe and have the performance characteristics desired by most people? I’ve seen Jay Leno showing off one of his steam powered cars and he was saying that it could easily go over 70 miles per hour…and that was in the early 1900’s. I don’t know what the range was, but 70 miles per hour would be a good benchmark for one of those performance characteristics that most people feel they need.

So…could you build a steam powered car, or use a steam engine in some way that would be practical in a modern vehicle? Say a steam/electrical hybrid (could drive using just the batteries until there was enough steam pressure to drive the car, thus getting rid of one of the drawbacks, that of having to wait while the steam pressure built, or dissipated). Or maybe some way to pressurize the pressure vessel in a similar way that a plug in battery or hybrid has it’s batteries recharged overnight, so you can just drive away without having to wait for the pressure to get to the point that the vehicle will move?

It’s probably not practical, since I assume if it were someone would be doing it, but I was watching a show on the History Channel about steam engines and thought it might be interesting to discuss it.

-XT

2

Popular Mechanics had an on-going quest to develop a steam powered car in the 70’s and maybe in the decades before and after. There’s been at least one car designed to run on compressed air which would be similar to building up steam pressure, and not subject to loss of heat. Then there are people seeking to break the land speed record for a steam engine powered vehicle, I guess because it’s not that high.

3

Actually, I think I remember (I’ll try to check later, so I may be wrong) but a Stanley Steemer held the land speed record for years at well over 100 mph, until a driver was killed at Daytona and the Stanley brothers decided records weren’t as important as a man’s life. This just when racing was becoming a major advertising hook for automobiles.

A big issue was indeed the “warm up time” needed to charge a boiler, but this was largely overcome by flash boilers (using a small boiler inside the big one, giving a quick start but not much reserve) allowing you to roll along while building enough pressure for sustained high speeds.

Also, systems that recycled the fluid/gas, like recirculating freon, eliminated the need to fill up with water.

And steam engines can burn anything, any heat source is acceptable for heating the fluid to produce pressurized gas (steam). And typically this is “external combustion” which does not produce all the pollutants of high speed, oxygen poor, internal combustion.

Finally, like an electric motor, no transmission is needed (huge weight savings) because a steam engine can develop full torgue at any rotational speed (a “flat power curve”).

Steam had quite a lot going for it.

4

I recall someone building one that was on a 20-20 type TV show. From what I remember it performed as well as a IC car, but had a warmup time of , well in the neighborhood of a minute, may have been less.

5

Interesting…I found this on Wiki that seems to confirm that at least some car designers have looked at steam power as late as the 90’s, so maybe it’s not as far fetched as I thought earlier.

I wonder what the down side is. Safety? It seems like such a car could offer an alternative to either ICE or battery, so I wonder why more people aren’t developing them.

-XT

6

OK, apparently not killed, but somewhat degraded. My memory isn’t perfect (like the rest of me ;))

From here (PDF). Apparently he was doing about 190 mph.

7

Surprises me too, and has for years. Performance wise, steam can do anything IC can do, and more. That flat power curve is a big deal because it means your engine can be ticking along at 2 rpm, barely moving the vehicle, but fully capable of towing whatever maximum load might be sustained. No transmission, no clutch, no running the engine up to its best torque producing rpm. Power is entirely related to boiler pressure, not rotational speed of the power train. So even a small engine could not just move your car, but tow your boat. Unlike a small electric or hybrid.

Safety isn’t a real issue either. As I recall (again my memory- sorry, confirmation required) some manufacturer (maybe Stanly) offered replacement of the entire vehicle if a boiler ever blew. Apparently this was either non-existent or so rare as to be negligible. And this was at the turn of the 19/20th century. I suspect both metalurgy and manufacturing standards may have improved since then.

8

I wonder if, with the lower weight requirements some sort of hybrid using electrical (battery or fuel cell) would be effective for either when you are starting up or for when you’ve used a lot of steam pressure and it’s rebuilding. It seems a natural to me, since they would seem to compliment each other.

-XT

9

Not quite a steam powered car, but back in WW2, when the Germans had requisitioned pretty much all of Europe’s fuel reserves for their war machine, people made do with gasifiers which were halfway between a steam engine and a combustion engine, could be adapted to existing car and truck engines and ran on wood or charcoal. Horribly unreliable at the time, could blow up as well but it worked.

Ironically, these days it’s the eco-conscious Germans who are looking into the technology again.

10

A fine but perhaps unnecessary idea. A flash boiler gives sufficient power to roll out in less than 30 seconds - the time needed to clip a seat belt and adjust the mirror. If that isn’t quick enough, a compressed air reservoir, charged the last time the vehicle was running, could provide literally instant though limited duration power. And in these computerized days, it would be trivial to program your car for at least normal commute times (“turn on boiler preheat at 6:49 AM to be ready for a 7 AM departure”).

But the greatest thing about external combustion is the ability to burn literally anything. You could stick a charcoal tray under the boiler, or firewood, or actual hard or soft coal. You might invest in a burner (like a bunsen burner) for alcohol, or kerosene, or whatever is cheapest and most available at the time. You could burn CNG, or even (ha, ha) gasoline. Hell, in a pinch you could burn grass clippings, perfume, or Jack Daniels. No great technological difficulty, and no obsolescence of the vehicle. All you need change is the module that provedes the heat. Everything else still works the same.

11

148.308 mph isn’t all that fast. That’s a record that doesn’t seem that hard to break.

One problem is heat loss. When you shut down the engine you’ll have a hot boiler at full pressure, and all that energy will be lost. Same problem when you stop at a traffic light. I think the more modern designs attempted to minimize the volume of steam maintained to minimize that problem and reduce the startup time.

Also burning fuel with air at atmospheric pressure is not going to be as efficient as burning it in a pressurized environment, and that compression takes energy. And once you burn the fuel in a pressurized environment, the exhaust might be better used to drive a turbine directly. A secondary steam generator might pick some efficiency from that mode, but if was practical it probably would have been done by adding a steam generator to the radiator of IC engines already.

Steam engines are more subject to corrosion than IC engines when made out of metal. There are alternative materials now, and the peak temperatures of a steam engine should be far below that of an IC engine even if the average temperature is around the same.

Canny Dan mentions that steam can start up at full torque, which is a great advantage, but at the same time it’s a limiting factor based on the pressure of the steam achieved at the top end. Unlike an IC engine you don’t develop more power simply by running the engine faster. To increase the engine speed or power the boiler and condenser have to get larger to handle the greater pressure and return of the steam to a liguid phase. The boiler in particular is a heavy component in a steam engine. It is to be strong enought not to blow up. And just like pressure cookers, in the old days, every steam engine exploded:dubious::rolleyes:

I wonder if modern materials have been investigated for steam though. A steam engine could be made of high temp plastics, and not even the most expensive ones either. The boiler would have to be made of metal, but the condensor would be made of a light metal like aluminum anyway. If you can make the engine light enough, burn fuel efficiently, transfer heat fast enough to a small boiler, and finally allow the engine to run in a generator mode for an electric hybrid so that excess steam was not wasted, maybe it could all work. But I doubt it. IC engines operate at very high efficiency thanks to years of improvements.

12

BMW has supposedly been tinkering around with a “steam hybrid” that captures some of the copious heat generated by a normal gas engine and uses it to make steam that drives a small steam engine that runs in parallel with the normal drivetrain. It seems kind of zany, but considering that something like 80% of the energy in the gasoline gets converted to heat instead of mechanical energy, it might have some potential.

See: Turbosteamer - Wikipedia

13

copied from Wiki above:
Uncomplicated and robust, the steam engine was claimed to give trouble-free, efficient performance. It had huge torque (1,100 ft·lbf/1,491 N·m) at zero engine revs, and could accelerate from 0 to 60 mph (0 to 97 km/h) in under 8 seconds.

An engine that developes huge torque *at zero revs *is a pretty amazing engine. You would think there would be some application for this sort of power, in some kind of machinery, if not automobiles.
A common modern misconception about steam vehicles is that they were slow. Passenger trains at the height of steam power were capable of sustained speeds greater than 100 miles per hour. I think it would be great to see modern versions of steam engines.

14

Couldn’t you just line the pressure vessel with some sort of ceramic? Jay Leno’s steam cars seem to have weathered the years pretty well, though I have no idea how much he’s had to rebuild them or how much maintenance they take. The coolest thing about them was that, like an all electric, they made no noise when in operation.

That would be more than fast enough for regular private transport in the US, since most speed limits are under 75.

True, but one of the things Leno mentioned is that you are constantly having to ration steam. Of course, that was in an older design, obviously (though his touring car had a closed system and went much further on a tank of water than the Stanley Steamer did). I was thinking that a battery and electric motors could fill in the gaps and give you the range and performance capabilities very comparable to modern ICE vehicles. I don’t know what the range of a modern steam engine would be…I suppose with a closed pressure system it would depend mostly on whatever fuel you are burning to provide the heat.

-XT

15

Damn, out at dinner so typing with my thumb; brevity and typos are inevitable. Thing is, no reason to stick with water. There are lots of fluids that vaporize at lower temperatures. And low pressures are also quite possible, just increase the size (area) of the pistons. Power is relative to the pressure, and the area of the surface being acted on. A recirculating freon system could run at (relatively) low temp and press, and still provide whatever power is desired. This also overcomes corrosion issues. And modern plastics may indeed be workable for the boiler and other parts. Steam is an old and well developed technology that was left behind partly in an unnecessary attempt to “modernize”. In point of fact, updating with today’s technology might offer some real advantages over other systems.

16

I imagine that cold weather might affect performance or operation, but that’s a great idea going with something other than water and using lower pressures.

-XT

17

XT, I’m a biologist, not a mechanical engineer, so I make no pretense of actual knowledge, and I’m not doing research on this damn phone. But I do not recall steam locomotives having winter performance problems caused only by ambient temperature. Suffice it for me to suggest that all these supposed problems were overcome more than a century ago. Steam was replaced by IC for a lot of reasons, but cold weather was not one of them.

18

Steam buses were quite popular since early 19th in Britain, starting from 1830, a time before railroads left them behind.

http://en.wikipedia.org/wiki/Steam_bus#1830-1895

http://www.realism-in-art.org/140825/Dr–Church%27s-London-and-Birmingham-Steam-Coach,-1833-(2)-large.jpg

19

Frozen locomotives were not terribly uncommon in severe weather, and there was a risk of rupture in some tubes if you didn’t drain the boiler completely when it was going to be shut down. For obvious reasons it’s not really a good idea to use antifreeze in a steam locomotive. The winter of 1917-1918 was noted for steam locomotives freezing up, sometimes on active lines blocking them from use by other trains (or so says an ancient edition of Scientific American I have).

I am a licensed professional Mechanical Engineer but I am NOT a locomotive nor steam engine expert (unless you mean Rankine cycle, in which case I am an expert). Tuckerfan may know much more about this topic than I.

20

Una, I was replying to **XT’s **comment about performance. I understand that an unused boiler (and associated water-filled parts) can freeze, causing no end of problems and inconveniences. And I suppose that a sufficient depth of snow might cause an operating locomotive to stop, and if it ran out of fuel, it might then freeze in place. But I meant that I didn’t think one could freeze while in actual operation.

If we’re talking about motor cars stranded during a blizzard, then yes, a water boiler is probably more at risk than a radiator filled with antifreeze. But in normal operation, meaning driving around from my house to the grocery store or the kids’ football practice, on modern roads here in 2011, I don’t think a steam car would be at any great performance disadvantage in winter. But I’ll be happy to take correction, if such is offered.

However, I don’t think the idea of a modern steam car should be limited to water boilers. And I think (or at least I hope) that the flexibility of heat source, the ability to burn anything with little modification except for the burn box if designed with such in mind, might make such a vehicle extremely flexible. Different regions might have different heat sources, allowing locally available products to be used without having to create a whole new infrastructure. Coal in the coal belt, oil, even crude oil, where it comes out of the ground, biofuels right on the farm, gasoline, CNG, or kerosene for city dwellers, etc. etc. Maybe just wishful thinking, but perhaps not. The technology is already here, and improvements, while desirable, are not strictly necessary to produce steam cars now.