A recent post over on the Tao of D&D about steam power reminded me of a good deal of ideas that players have put forward over the years across various editions of the game to get a steam engine to work within the framework of D&D. Now, assuming that the idea of a steam powered vehicle does come to mind... lets look at some of the technical limitations that can be bypassed with the wonders of magic and not need any form of super advanced metallurgy to be perfected.
Okay, so we need a boiler with a pretty standardized shape. I know it is from 3.x D&D, we have the Shape Metal spell. Like it's cousins for stone and metal, it can do a good deal for getting a perfect weld between two metal pieces far more efficiently than rivets. Hey, we can even get the water and steam lines in this way.
Metals not strong enough to keep pressures contained? Again, 3.x gave us a spell that doubles the strength and sturdiness of the materials used. This is assuming that using common metals like iron or primitive steel are used and not some of the more fantastic metals, like Adamantine, renown for it's strength in setting. Heck, that spell goes a long way towards keeping metals that can handle fatigue well across the machine... though it would take experimentation to find which parts need the refinement and reinforcement.
Sustainable heat? Well, assuming that you don't have a ready fuel source and are wanting to stay magical, we have the fun spell of Heat Metal. Through either refinement or a permanency spell, you can keep the metal at a constant state of searing... what ever searing counts as. I am shooting for honestly what I consider searing (IE, from cooking) of 150* C (300* F) Min to about 350 F. Ouch. This will get water boiling pretty good. That would be a good means
Now that a heat source has been secured, how to control the heat? It can't exactly be held now... A ceramic (IE: magically enhanced bricks) covered platform with mechanical controls to lower and raise the platform into contact with the boiler.
A constant supply of water can be supplied by either... well, making sure water is available or if staying with magic being used and not needing a network of water towers everywhere or keeping track of where all lakes and rivers are... we have our classic stand by of one or more decanters of endless water. That is one of the single most useful items ever.
There are a few more problems that will need to be fixed over time and experimentation... like a steam release valve... or actually figuring out how to harness this great new concept! Someone will come along soon with ideas like blowing the high pressure steam across a light weight water wheel. Refining it till you have a primitive turbine, Mithril comes in wonders here... since the water wheel and the wind mill seems to be understood in a DnD setting more than a piston engine. It won't be efficient but it is a good leap forward in giving mechanical power for crafting.
Will it be cheap? No. Will it be common? Not till someone figures out how to refine it and make it cheaper. Will it be revolutionary and bring about the industrial revolution? Probably not change the setting in a single day or even a few years. But it could be fun.
Eeeeeeh... just a few ideas. Just wanting to toss them out in the open.
