Dear Jim and Family,
Its true that boiler maintenance and safety are a serious concern. As my wife is a rail fan (train chaser), she knows a bit, and knows people who know a lot more. One of these was kind enough to send me this info in his reply.
"Bear in mind that the great costs mentioned are all meant to get the boilers up to federal-mandated standards, i.e. extremely safe conditions. If you just want to get it to function, you don't have to do near as much work. The problem of course is that while under steam you have several thousand gallons of superheated water just looking for a breach in the boiler that will allow that water to expand something on the order of 1800 times in volume instantaneously. Boom.
While the concept of a steam engine is simple, its implementation grows more complex with its scale. How do you inject water into a vessel already at 250 psi? How do you preheat that cold water so that the thermal shock of the water entering the boiler doesn't fatigue and eventually crack it? How do you deal with the impurities in the water inevitably left behind as the
water evaporates and departs as steam? There are systems designed to take care of all of that, but that's just more hardware to break and
The only restrictions on track depend on the particulars of the engine -- the curves shouldn't be too tight for its wheelbase and the bridges should be strong enough to support it."
My thoughts center on use of stainless steel (including the new cheap nitrogen impregnated stainless steel) listed as Nickel-free stainless 404GP and 445M2 alloys.
Cheap stainless changes the entire equation on affordable and reliable steam since you end the spalling problem in the firebox. There's still quite a few old steam engineers running around, as well as enthusiasts restoring and running old engines they buy for a $1 and "please remove this from my property" from the former owner, often a lumber yard with a railroad spur somewhere in the back. Steam fitters and boilermakers unions have men capable of welding up pressure vessels. They need the plans, but rail fan associations typically have those, as well as in archives of existing railroads. Despite the company reputation, the people working there aren't all ba****ds. Many genuinely love trains, and most will keep them running, though the legal issues of running excursions on active lines is a major regulatory headache. Think of railroad companies being massively burdened with regulations and you'll sympathize with their headaches.
The original discussion was regarding restoration of old engines and using them to haul people around. That's a good idea, for style if nothing else, but not the best idea for function. If you build steam engines from the ground up, there's a degree of sense in using hybrid techniques, as hybrid trains came decades before hybrid cars. A hybrid steam engine running an electric motor and batteries would resolve a lot of those pressure, maintenance, and safety issues affecting traditional piston train engines. If any mechanical engineers are reading, give some thought to designing a modern steam engine with the advantages of cheap stainless steel, modern pressure vessels, steam turbines, and automatic relief valves, and an eye towards multiple fuels, from low quality oil, coal, and even firewood if need be. Thanks to Peak Oil, trains are our best bet to offer some shipping between cities and towns, and local transport of goods and people. I think there's a great deal of merit in this, and a real future with them, despite their initial hurdles. Best, - InyoKern
Dear Jim and Family,