Are steam locomotives more viable than diesel in a post-apocalypse?

Question

So, context: This is some time after the apocalyptic event, and society has had a little time to re-build. The apocalyptic event in question physically destroyed a large number of cities, and killed most of the human population. It did not poison the air, or make the surface world uninhabitable. While much of this world is now desert, most of the desert predates the apocalypse.

There is very little coal in this world; as a result, steam locomotives have historically been oil burners. At some point in the past, oil refining was discovered, and diesel-electric locomotives became the dominant form of rail transport. (bonus question: with the majority of locomotives using oil rather than coal, how much faster would diesel locomotives have overtaken steam?)

Considering that society has recovered to the point that trains in general have become not only possible, but worth the time and effort, how likely is it that this society is already able to refine oil to the extent needed to run diesel-electric locomotives?

Answer 1

Depends on how much infrastructure survives:

So diesel engines can run on a lot of things:

• Blue Crude
  • water + electrolysis + CO2 + Fischer-Tropsch process == blue crude. You can run an engine on this directly apparently.
• Vegetable oils.
  • Used for cooking and unused.
• Biodiesel:
  • Processed crops. Ie Rapeseed (canola crop). Palm oil. Any crop really.
  • Also animal fats
• Some experimental algaes can make diesel fuel.

If you're wanting to stretch diesel fuel, you can add Ethanol or Butanol. Ethanol you can make post-apocalypse quite easily. You can stretch it even further and run with even lower quality fuel if your train has a fuel pre-heater.

So just because you don't have big oil companies anymore doesn't mean your diesel engines are useless. Blue crude will need power, water, and an intact processing facility. Others will need farmland and some processing, which can be as simple as a press and fabric for filtering.

To answer your question directly, if society is totally gone, steam engine wins. However if there is pockets of surviving industrial facilities or agriculture then I wouldn't write diesel off unconditionally.

Answer 2

Take a trip to your local train museum:

To get a good idea about this, go to your local train museum. Here in Minnesota, we have a long history of trains, and I have old train maintenance facilities right here in the Twin cites. Find one that's restoring a steam locomotive. They SOUND simple, but the engineering is only "simple" because it's older. There are hundreds of miles of pipes, thousands of joins, and vast amounts of engineering that go into steam engines. They are VERY MUCH dependent on a large and integrated industrial complex to even function. The maintenance was the real killer with such complicated machinery. Diesel won out because it was simpler to use diesel to make electricity that actually runs trains. Steam relied on mechanical propulsion, which is actually MUCH harder from an engineering standpoint (sorry steampunk folks).

Rails are just a physical means of having a better road with less resistance to carry really large loads (and large machines to pull those loads). You won't have railroads in a post-apocalyptic society without a fair amount of infrastructure. But Diesel engines with have a lot of versatile applications, while steam is likely to be relegated to electrical grid generation like it is today. Redeveloping Diesel means both electrical generation, but also trucks, cars, trains, small boats and all that comes with them.

So in a world of limited resources, you'd start building trains with Diesel using existing engines and tracks, but then you'd CONTINUE using Diesel because it's ultimately simpler, requires less maintenance, with known engineering that applies across a large number of applications.

• PS in a desert world, I wholeheartedly agree with user6760's assessment that the shortage of water (and likely wood, the easiest source of fuel for early-model trains) due to desertification will be as much or more of a barrier to the use of steam engines as the engineering. Diesel won't require the constant refilling with water that steam engines require. And if wood isn't critical for fuel (as trees are NOT abundant in desert conditions) then the existing oil-based fuels will already require an oil infrastructure that lends itself well to Diesel engines. Diesel fuel is relatively easy to make from crude oil, and can be even made today by people in their own homes from cooking oil. I inherited a piece of land in Kansas with very low-grade oil, and if I wanted to, I could make Diesel fuel from it (I have a chemistry degree, but it's not impossible). As Steven Klassen pointed out, fuel isn't a big issue.

Answer 3

The apocalyptic event in question physically destroyed a large number of cities, and killed most of the human population.

If most of the humans are dead, the economics, the society and effort for rebuilding will be very different. One may even see a return to even more elementary technologies since oil extraction itself can be unfeasible, and coal anyway didn't exist in your world.

Thus, since most of the world is desolate of humans (and by extension other animals), if there is enough tree cover, then the trees could be used to create charcoal/be burnt as firewood directly to power steam engines.

This could help make steam locomotives simpler to bootstrap than oil/coal.

bonus question: with the majority of locomotives using oil rather than coal, how much faster would diesel locomotives have overtaken steam

The problems with oil in general are:

1. Special Storage and transport requirements - oil spills, coal stacks
2. Refining capabilities - most coal can be burnt as is, oil as used today is highly refined
3. Extraction technology - coal is simply mind from surface / sub surface mines, oil can be offshore, or deep well, or shale oil etc

Thus, depending on how the oil is available in your world (good quality or not, easy availabiltiy - say a lake of oil was covered with nitrogen/ inert gas and hence is in tact, natural terrain allows for easier transport etc), you can tilt the benefit towards oil.

Are steam locomotives more viable than diesel in a post-apocalypse?

It therefore all depends on energy efficiency and resource abundance that society is able to achieve. Think of it in terms of how much 1 unit of fuel lets you move intended weight by, and how easy it is to come across that 1 unit of fuel. (The fuel is spent in transporting fuel weight + dead weight + intended weight).

Answer 4

As they rebuild their industrial capacity, steam will come before diesel. Yes, steam requires a significant industrial base to build and maintain, but diesels require even more. So even if they were already at the diesel level before the apocalypse, they'll revert to steam afterward, for some time at least.

Fuels aren't the issue. Diesel, and even more so steam, is surprisingly flexible in what it can run on. Honestly, my concern is the "desert" part. In real life, railways in deserts were generally the first to dieselize. I suspect that's why some places (namely, inland Saudi Arabia) didn't get railways built at all until diesels were available. Steam needs lots of water.

So, they'll redevelop steam first. The question is whether they'll rebuild much in the way of railways at all until they redevelop diesels because of that water shortage!

Answer 5

A resounding "Yes."

Steam locomotives came about before Diesel for three reasons.

1. They're easier to make. The thing most people don't realize is that diesel engines aren't just "a gas engine burning diesel." The most notable difference is that the diesel is combusted by subjecting it to high pressures. This means you need two things to make a diesel engine, both of which aren't feasible in an apocalypse:

   1. High-quality steel so that it doesn't warp or rupture from the pressure
   2. Much higher machining tolerances than a steamer, especially around the piston heads.

2. They're more maintenanceable. Even if you can get an engine, diesels have a lot of little fiddly parts that can get broken, gunked up, or otherwise FUBAR'd. As @TristanKlassen mentioned, a real life example of this is Guatemala during the '60s.

3. They don't expend non-renewables. This is a post-apocalypse wasteland we're talking about here. The only sources of diesel, automotive oil, and half a dozen other things you must have to run a diesel engine will be what you can scavenge. This is especially the case with the oil and diesel; even if you can find a large enough supply, it'll go stale before long.

Answer 6

1. You can build a steam engine with a blacksmith, a foundry, and a lathe. And many did. You can build a foundry furnace and a blacksmith forge out of rocks and clay. A blacksmith can build a workable lathe. This is as close as you can take industrial civilization to basic raw materials. To build an internal combustion engine, you need precision grinding, which means you basically have to rebuild the steam era before beginning. To build a workable electric transmission, you need even more.

I used to work at a factory that made generators similar to those used in locomotives. Each winding was wrapped in 5 layers of different insulation types, at least 2 of which and probably 4, were materials that didn't even exist in the steam era. There's a reason it took so long to make diesel-electrics workable!

2. It doesn't matter what you can burn in a diesel. Every potential fuel requires refining. To build a refinery requires infrastructure. Again, to build the oil era from scratch, you have to first build the steam era. You can dig a steam engine's fuel out of the ground with a pick and shovel. And a blacksmith can make those.

3. Steam power can be kept working in primitive conditions when i.c. power can't. If your steam engine breaks a rod, you remove the rod, heat up your forge, draw out the rod, and forge weld it. Back in action. And this was done all the time. If you're making your own wrought iron, you probably won't even need to flux that weld.

If a gasoline or diesel engine breaks a rod, you need to have spare parts.

Modern technology and beyond, is just not forgiving of primitive conditions.

Answer 7

It depends on their technology.

Diesel is much more efficient and versatile, but require a much more sophisticated level of metallurgy and fabrication capability than steam does. Mind you, this is diesel-electric, which also requires the knowledge and tools to make high-power generators and electric motors.

how likely is it that this society is already able to refine oil to the extent needed to run diesel-electric locomotives?

The fuel is almost irrelevant, for either case.
Both can run on a variety of reasonably easily made fuels. The difficulty with making fuels have to do with efficiency, and economy, and sustainability. The actual processes are comparatively trivial.

Answer 8

Unless your apocalypse took place in a location with antiquated rail technology (like most of the US) that you're re-using, neither steam nor diesel is a good solution. Your (exitsing, rebuilt) locomotives are electric. You can run them with power generated by hydroelectric dams, which should be easier to restore than building an oil refining or wood/coal supply chain. See for instance the railways in Europe.

Answer 9

You forgot one thing: steam engines can burn wood.

Wood-burning is a very inefficient method of energy production, but in a post-apocalyptic period, how much trade and travel is there actually going to be? Remember, until sometime in the early 1900s, if I remember correctly the average person traveled less than 350 miles from his home YEARLY.

So efficient, long-distance personal travel is immaterial and as for goods, wagons and boats would suffice, as most of the population of the world lives near some type of navigable seaway.

Answer 10

Assuming that this world has lost the manufacturing facilities to make diesel parts, or even the ability to refine proper oil to lubricate the engines, and all diesel locomotives that still exist no longer run, a steam locomotive can be operated in a low tech environment, as it can run on a lot of fuels (including oil), and the parts and lubricants needed to run the steam locomotive are much simpler.

However, you would have to build the missing infrastructure to support a steam locomotive, that has long since been abandoned.

Steam locomotives can run maybe 80-100 miles before they have exhausted their water supply. So you would need large amounts of water at regular intervals, plus a way to get that water into the locomotive. This is the large barrel on stilts that you might see in some old west films, adjacent to the tracks.

You would also need a lot of maintenance facilities to be built - steam locomotives require more frequent rebuilds, due partially to the running parts being exposed to a very corrosive substance: superheated live steam. That is why most cities in the steam locomotive age, even smaller ones, had at least one roundhouse - to rebuild locomotives.

And finally, you would have to rediscover the art of building and running a steam locomotive. Compared to a diesel, they require a lot more attention while running, to insure the water level doesn't get low (boiler explodes), to keep the running gear lubricated (largely a manual process), and manage the firebox to get an even distribution of heat, to mention a few.

The primary reason diesel locomotives replaced steam locomotives in the 1950's and 1960's was the lower maintenance costs. Diesel locomotives had a much greater range, didn't have to stop for water, didn't need to be rebuilt nearly as often, and made more efficient use of fuel than steam locomotives.

But, if you don't have the infrastructure to keep a diesel locomotive operating, then the steam engine can be operated with a lower level of available technology.

Answer 11

The hot-bulb engine will run on most fuel. They use a compression ratio of 3:1 to 5:1, a diesel uses around 15:1 to 20:1. This lower pressure allows it be made from lower-grade steel. However, they are about ⅓ of the efficiency of modern diesels, and require a blow-torch to heat it to running temperature before it will start.