I’ve been tinkering for awhile with some ideas for an RPG campaign setting. It’s generally a low-fantasy medieval world without much in the way of magic, monsters, or nonhuman intelligents running around. That is, all three of those things do exist, but they’re rare enough that most people, wandering adventurers included, will live their lives without ever seeing them. One idea I had, that I don’t think i’ve seen in a fantasy setting that wasn’t some sort of steampunk before, is the idea of primitive automobiles existing in the game world - not widespread, but extant, and probably a sort of status symbol for those wealthy enough to commission one.
Which leads me to my question. The world i’m envisioning is DEFINITELY pre-Industrial Revolution. There are no factories, no watermills, and tools and machines are made by hand. Assuming that the necessary scientific principles (internal combustion, etc.) are known and understood, and a fuel source (probably alcohol-based) were readily available, would it be within the realm of possibility for a group of skilled craftsmen to build and assemble, entirely by hand, a primitive automobile on the level of one of Ford’s earliest models?
I wouldn’t go with the internal combustion; IIRC that requires significantly-greater precision than external combustion. I’d go with a steam-powered vehicle. If you didn’t care about bystanders and had enough water and fuel, you could use a steam rocket, even: just a nozzle on the boiler. This does require smooth roads, though, so best get the legions building.
Very interesting question. My biggest concern would be the precision that could be attained with hand tools. I/C engines need parts that tight enough together so that air and liquid doesn’t slip between the parts very well. Poor precision = no compression = no ignition.
Carburators are another vital piece of the vehicle that requires precison to meter the fuel. You would need a needle valve that could be adjusted to match the amount of air going into the carb.
Then, for a spark ignition engine, you need some type of wire. The simplest type of ignition would require a fairly precise coil of wire and a magnet.
I’m not saying it’s impossible. But, I would have a hard time believing that even the most skilled tradesmes would invent an I/C engine and automobile before they would invent some type of waterwheel or coal powered mill.
I honestly don’t think internal combustion would be that much harder than external combustion (disregarding any jet technology, like a steam nozzle mentioned above). You still need to make pistons, wankels, turbines or something like that unless you want to look like an idiot riding a steam rocket. The better your materials and better the clearances you can achieve the more efficient your implementation will be, but it’s not nearly outside the realm of pre-industrial manufacture.
If you have the knowledge, raw resources, fuel and time, and already have technology to make mortars, swords, bronze statues and silverware, you can make a car. It might look ridiculous, and explode at times, but it’ll be a working car.
Smapti, you might want to consider using an engine known since antiquity, the Aeolipile. In reality they’re highly impractical, but one would be just the thing for a fantasy setting. In the Discworld novel Small Gods, Terry Pratchet describes a motorboat powered by one. If I recall correctly, it blows up.
Most of the innovations that make a self propelled vehicle possible (and practical) have applications in a wide range of other areas.
Unless you have a Leonardo Da Vinci level genius coming up with most of them on his own, those ideas will already have affected the tech level of your society to some degree.
You could always have your guys use those landsailer things.
(I can’t recall if that’s what they are actually called)
You’d probably do better with a spring or something. The mechanism would be simple, but you would need beasts of burden or such to rewind it after every use–which would limit it to the upper classes.
The main issue would be steering it. As I understand it, most automobiles weren’t practically maneuverable until rubber allowed cars to get a good grip and a widened footprint. Prior to that, a minor correction could send you careening or not change your direction at all. So probably you would want something like a cheese-filled (? something that wouldn’t leak, while being relatively bouncy) sheep bladder-based tire.
A skilled craftsman could build a steam or IC powered vehicle, the real question is: How much time are you allowing for him to do this? If the person was insanely clever and had several decades of free time, they could come up with an IC engine. More realistically, steam, aeolipile, or spring (I think that Da Vinci designed such a vehicle) would be good choices. Pick up a copy of Connections by James Burke, The Ancient Engineers by L. Sprague De Camp, Engineering in History by Richard Shelton Kirby, Ancient Inventions by Peter James and Nick Thorpe and/or Caveman Chemistry: 28 Projects, from the Creation of Fire to the Production of Plastics by Kevin M. Dunn to get an idea of what was technologically possible in more primitive times. For tires, you’d probably want to go with something like those found on steam tractors.
Now, mind you, the way the technology developed was strongly dependant upon a number of variables which might not exsist in your scenerio. For example, had civilization got going in a part of the world where rubber trees are found, then solid rubber tires might be possible. Or, if the advanced civilization is in some place like Norway, Sweden, or other perpetually frozen part of the world, then a snow mobile might be the self-propelled vehicle of choice.
Quite often a technology will sit around (some times for hundreds of years in some cases) before someone thinks to apply it to something else. So I’d say you shouldn’t feel restricted by what we developed over time. After all, if the Greeks had paid more attention to Hero’s inventions, they could have had automated machinery long before it was finally developed.
Speaking of skilled craftsmen and oodles of time,I read somewhere about British POWs being kept in Japan who built a metal lathe capable of screw cutting with not much more than a hacksaw and file,scavenging materials wherever.The entire length perhaps one foot.
We had a thread not long ago including a link to an analysis of how one could make a complete machine shop starting only with raw materials. So sure, you could do it.
THe internal combustion engine in a pre industrial society was featured as a plot device in one of the Deatthworld stories by Harry Harrison in 1968. I am pretty sure this was in the first half of the third part of the trilogy.
I remember that thread but not the specifics; link?
If I understand the OP correctly, it’s a given that the blueprints, specs and so forth are available, and the builders understand the concept, it’s just a matter of “can it be done?”. I see two major problems, both engine related.
The first is precision: can you make the parts precisely enough? I’ve heard of people in Afghanistan making AK-47s with steel, the specs, a set of files and a micrometer. But how do you make the micrometer? Where do you get the original level of precison to copy?
The second is steel. I doubt very much that wrought iron could be used for engine parts, no matter how well crafted. Ditto cast iron. Ditto hand-laminated steel. At a minimum you’re talking about a reverbatory furnace capable of producing cast steel. That’s going to be very difficult to build with pre-industrial technology, even if you know how.
IIRC, that thread was lost in the Winter of Our Missed Content. However, here’s a series of books that tell you how to do it.
The earliest steam engines were built using calipers, which are far less accurate than micrometers. If you read Connections by Burke, he talks about the level of accuracy available at the time the first steam engines were built. It wasn’t very high, and Eli Whitney hadn’t even come up with the idea of interchangeable parts at this time.
Most engine blocks until fairly recently were cast iron and cast iron pistons are fairly common in older engines. A reverbratory furnace isn’t that complex to build, after all, it’s basically what many peoples used to make bricks or bake bread. Wrought iron is a type of forging and you can buy forged pistons. Laminated steel probably wouldn’t be much different than chrome plating.
I can tell you what an IC engine built under such conditions would look like. There’d be a lot of exposed parts, it’d have only a small horsepower rating (probably something like 20 HP for a 400 CI engine, like one could find on many cars in the early 20th Century), run at very low-RPMs, need frequent adjustments, and probably breakdown quite often. As for fuel, one could use alcohol, methanol (the original Model-T was designed to run on gas or methanol, BTW), or natural gas (which was being tapped and used by the Chinese when the Romans were still running around). Still, whatever fuel is used, the engine’s going to get lousy fuel economy. A diesel engine is another possibility, I suppose, but it would have similar problems to a gas engine, even though it wouldn’t have the problems of needing an ignition system.
A steam engine would offer the best possibility in terms of things like HP, fuel economy and simplicity.
That would be great, because then you could have the villagers ranting about some knave who double-parked his Springloaded Utility Vehicle in front of the well.