And now for a particularly silly notion... TANKS!!!

AirTech wrote:
But you don't ship wood - you cut it off the side of the road (or pinch it from the farmers wood piles if you have an army with better guns than the farmers).
Wood fired railway engines and steam tractors were widely used anywhere where a forest was to be found - (England and Europe had by this time converted the forests to ships and charcoal so coal firing was more common in developed areas). A wood burning engine can also easily be adapted to burn coal or oil (the reverse is not true as the fire boxes on a dedicated coal burning engine would be too small for wood).

That is completely unrealistic. If nothing else, you don´t use tanks where there are big forests, because that´s BAD terrain for them.
You´re going to be shipping fuel no matter what.

And how often do you seriously think you can grab wood nearby? With the rest of the army doing the same(for cooking and for heating and for lighting)?

Any large army tends to resemble a plague of locusts when it moves across terrain, ground it has passed over is already used up. With wood being one of the first things grabbed.

And any tanks are going to use MUCH greater amounts than local woodlands can support.


Sweden by the way, never "converted" its forests to ships ( like Denmark did ), much thanks to initiatives taken in the 16th century to cultivate new oak forests for future shipbuilding.
Oaks that would take a century or two before they we´re good to be used, that´s forethought...

Tenshinai wrote:

AirTech wrote:
But you don't ship wood - you cut it off the side of the road (or pinch it from the farmers wood piles if you have an army with better guns than the farmers).
Wood fired railway engines and steam tractors were widely used anywhere where a forest was to be found - (England and Europe had by this time converted the forests to ships and charcoal so coal firing was more common in developed areas). A wood burning engine can also easily be adapted to burn coal or oil (the reverse is not true as the fire boxes on a dedicated coal burning engine would be too small for wood).

That is completely unrealistic. If nothing else, you don´t use tanks where there are big forests, because that´s BAD terrain for them.
You´re going to be shipping fuel no matter what.

And how often do you seriously think you can grab wood nearby? With the rest of the army doing the same(for cooking and for heating and for lighting)?

Any large army tends to resemble a plague of locusts when it moves across terrain, ground it has passed over is already used up. With wood being one of the first things grabbed.

And any tanks are going to use MUCH greater amounts than local woodlands can support.


Sweden by the way, never "converted" its forests to ships ( like Denmark did ), much thanks to initiatives taken in the 16th century to cultivate new oak forests for future shipbuilding.
Oaks that would take a century or two before they we´re good to be used, that´s forethought...

I agree, Tenshinai, but with the following qualification. Whether or not your statement is true not only depends upon how forested the area is -- and there is lots of unconsecrated forest in Western Siddarmark and the Borderlands-- and how many actual tanks would be moving and how fast they move through the area in question.

That being said, I do think you are right. It is unlikely that wood can be regarded as a reliably available fuel for tanks. And if you are going to transport fuel, you are better off transporting coal which is more energy efficient. However, one can also visualize wood as a back up in a context where coal becomes scarce for whatever reason.

Don

WOW!

I just saw the most interesting vignette on a show called "How It's Made." Like... Literally just saw it.

And immediately thought of this thread, having browsed the forums an hour ago or so.

So the idea was a radial steam engine... In all my reading so far, I could only visualize an in-line steam engine. Whether it was dual expansion or even triple expansion. I had this picture in my head of something that was linear. I should have been thinking about the WWII radial aircraft engines!

The radial engine I saw on the show used small diameter (but relatively long length) tubing that was rolled up in a coil about 3 feet in diameter and about 1/2 inch thick. One roll for each "cylinder," 6 total coils for the 6-cylinder engine on the show. Water in at one end of each roll, superheated steam out the other end 5 seconds later with virtually any flammable fuel.

The cylinders were arranged radially around a central camshaft and produced lots of power from a very small package.

Additional benefits: A simple condenser recycles the steam after the heat energy is pulled out of it. No hydrocarbon lubricants were required.

Watching the video, I was reminded of the old Mazda radial engine...

So in my mind, the powerplant for a tank is now a much more feasible thing. Now we just need to overcome the limitations of armor manufacturing... Hmmm. How to make enough steel?

I'll have to do some more digging and see how much power output you get and what kind of power to weight ratio you can obtain.

A quick follow-up:

Some research on a small, currently available, 6-cylinder radial steam engine: 25 cu in; Operating RPM: 50 to 3000; Operating pressure: 25 to 200 psi; 15.8 HP; Weight 18 lbs without condenser.

WeberFan wrote:Watching the video, I was reminded of the old Mazda radial engine...

NIT: Mazdas have a Wankel Rotary engine, not a radial engine.

WeberFan wrote:A quick follow-up:

Some research on a small, currently available, 6-cylinder radial steam engine: 25 cu in; Operating RPM: 50 to 3000; Operating pressure: 25 to 200 psi; 15.8 HP; Weight 18 lbs without condenser.

Sorry to burst your bubble, but while i can´t be sure of everyone else, i already took the kind of engine you suggest, as well as RFCs pet favorite (Doble), into account.

Tenshinai wrote:
That is completely unrealistic. If nothing else, you don´t use tanks where there are big forests, because that´s BAD terrain for them.
You´re going to be shipping fuel no matter what.

And how often do you seriously think you can grab wood nearby? With the rest of the army doing the same(for cooking and for heating and for lighting)?

Any large army tends to resemble a plague of locusts when it moves across terrain, ground it has passed over is already used up. With wood being one of the first things grabbed.

And any tanks are going to use MUCH greater amounts than local woodlands can support.


Sweden by the way, never "converted" its forests to ships ( like Denmark did ), much thanks to initiatives taken in the 16th century to cultivate new oak forests for future shipbuilding.
Oaks that would take a century or two before they we´re good to be used, that´s forethought...

Tanks in scrub on the other hand can be very useful - think bulldozers with attitude. Vehicle goes through scrub and army follows behind - worked for the Russians in WWII.
Most of the farming area's in Australia were cleared this way starting with Big Lizzy (which had a 10hp engine and a top speed of 2km/h but serious torque and traction). Scrub being defined as trees smaller than 200mm and flat land. Most modern remnant forests are in land that is too steep for broad acre farming but this is rare compared to prairie landforms.
The idea however is to shorten the logistics train from a thousand miles (or ten thousand depending on where your refinery and oil field is) to twenty. This is one of the reasons the US Army paid $60 a liter for fuel delivered to front line units in Afghanistan (and has been investing in solar power systems ever since).

How would a steam engine tank (coal or wood, whichever) deal with the problem of feeding fuel to the boiler ? And automatic feeding system for solid fuel seems like a very large pain in the posterior to design. Particularly one supposed to to keep working while the tank does silly things like going up and down (or rather down and up) ditches, bumping into inconvenient obstacles, and getting hit with fast moving iron balls... all ordinary hazard of a battle field.

The alternative would be to have a dedicated soldier for feeding the boiler... which means a boiler open to the inside of the tank, which would raise serious heat issues and possibly a serious burning coal spilling hazard, as above...

AirTech wrote:Tanks in scrub on the other hand can be very useful

As long as it´s flat enough, sure. But scrubland doesn´t have nearly enough wood to supply steam engines, unless you gather widely, which would be dangerous and tie up a lot of people at or near any frontline.

AirTech wrote:The idea however is to shorten the logistics train from a thousand miles (or ten thousand depending on where your refinery and oil field is) to twenty.

Yeah, but that´s another of those "sounds good in theory" ideas. How much of your troops will be stuck babysitting the people gathering wood? To avoid opposition picking THOSE off pennypacket style.

Having a good railroad and advancing alongside it is very likely the best option if you want to play with tanks, even if they´re petrol or dieselpowered. Steampowered just means they will need more per distance moved(*3 to *10 all included ).


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Halancar wrote:How would a steam engine tank (coal or wood, whichever) deal with the problem of feeding fuel to the boiler ? And automatic feeding system for solid fuel seems like a very large pain in the posterior to design. Particularly one supposed to to keep working while the tank does silly things like going up and down (or rather down and up) ditches, bumping into inconvenient obstacles, and getting hit with fast moving iron balls... all ordinary hazard of a battle field.

The alternative would be to have a dedicated soldier for feeding the boiler... which means a boiler open to the inside of the tank, which would raise serious heat issues and possibly a serious burning coal spilling hazard, as above...

One of the historical reasons why steamtanks became vehemently rejected.

Halancar wrote:How would a steam engine tank (coal or wood, whichever) deal with the problem of feeding fuel to the boiler ? And automatic feeding system for solid fuel seems like a very large pain in the posterior to design. Particularly one supposed to to keep working while the tank does silly things like going up and down (or rather down and up) ditches, bumping into inconvenient obstacles, and getting hit with fast moving iron balls... all ordinary hazard of a battle field.

The alternative would be to have a dedicated soldier for feeding the boiler... which means a boiler open to the inside of the tank, which would raise serious heat issues and possibly a serious burning coal spilling hazard, as above...

As opposed to the WWI idea of petrol powered engines and fuel tanks? The British MkV had a crew of 8. One hit from serious artillery nearby and the crew is roasted in spilled petrol from ruptured fuel tanks. Compared to this spilled coal is a non-event. Steam leaks are another problem and for these, containment is required and the firing doors are a significant hole in this.

The heat issues are significant, and was a real problem in the British type K steam submarines. Ventilation helps a lot, and a steam engine actually makes this easier as the boiler draft helps with ventilation. (Ventilating a submerged submarine causes interesting problems (blocked fly screens and all that... ))

Automatic firing of solid fuels is relatively easy with a walking bed grate, wood chips or lump coal are usually used with this but hay and bagasse (sugar cane waste) also works. Blown fuel feeds requires coal dust or saw dust which are hard to obtain in the field (fuel slurries are even worse but the US Army have coal dust slurry as an accepted alternative fuel for its ground gas turbine engines, including tanks).

You have to bear in mind that most peoples mental images of steam engines are state of the art circa 1880. (The rail industry kept building these into the 1930's). Serious state of the art systems for fired steam generation have more in common with nuclear systems than most people realize (American coal fired power plants are decidedly NOT state of the art (typically 1950 standard), the current generation Indian and Chinese plants are much cleaner and more efficient).