Steam Power For Tanks Ideas And Inspiration

[tankmodeler]

Err...I think you will find that there are far more power generation units utilising steam turbines that are fuelled by coal, oil, natural gas etc.  Nuclear powered units are only one option!

Oh, I know that. I'm just being contrary to be a pain in the arse!  :)

The original article as a general rule suggests, "that a steam engine of 500-horsepower is the equivalent of a 1000-horsepower internal combustion engine." so you're getting twice the power for half the size?

Is that how we should interpret that statement? I would read it as for the size of a 1000 hp unit you only get 500 hp. Or for the same HP you need an engine twice the size.

And, of course, your comment on the ancillery equipment is very true and is also where the bulk of the mass of the system is.

For example, the engine for the M1 tank is the Lycoming (now Honeywell) AGT1500C gas turbine that produces about 1500 hp and weighs about 2500 lbs. The actual gas turbine part of the engine, i.e. where the air is compressed, fuel burned and power extracted, is pretty small and only weighs about 400 lb. The regenerators. intercoolers and preheaters that allow the powerpack to be efficient enough (barely) to be practical in a tank weigh the other 1100 lb. Plus the 500 gal of fuel. And no water. And all of this is with modern materials and processes.

The Maybach engine in the Tiger 1 also weighed about 2600 lb for 690 hp. If we use the ratio from the article per my interpretation above (could be wrong, but am going with it for now) then the basic steam turbine engine to produce 690 hp would mass about 5200 lb using equivalent WW II materials and science. Using the ratio from the AGT1500 of ancillery equipment to basic engine weight of almost 4:1 (1100:400) then the steam system mass in a Tiger-sized steam turbine engine might be 20,000 lb.

Plus fuel and water.

These are just spitballin' type numbers of course, but a steam turbine engine that is efficent enough to run a tank any tactically useful distance is bound to be many times the size of a similar internal combustion engine. Once the volume starts to go up you can either reduce the protection around the entire vehicle to keep the mass down, or increase the mass greatly and suffer a significant reduction in performance.

Or, of course, you can cover the hull and turret in rivets, plant a big smokestack on the engine deck, put a smoothbore breechloader in the turret and call it a steampunk tank and built it.  :)   

Paul

[GTX_Admin]

Or, of course, you can cover the hull and turret in rivets, plant a big smokestack on the engine deck, put a smoothbore breechloader in the turret and call it a steampunk tank and built it.  :)   

 :)

[Weaver]

The original article as a general rule suggests, "that a steam engine of 500-horsepower is the equivalent of a 1000-horsepower internal combustion engine." so you're getting twice the power for half the size?

Is that how we should interpret that statement? I would read it as for the size of a 1000 hp unit you only get 500 hp. Or for the same HP you need an engine twice the size.

The full quote is this:

Doubling steam power does require about eight times the heat exchanger volume, but nevertheless, some of the engines themselves, as just noted, are very small. And, delivery of power at the drive sprockets of a tank is the proper method of comparison because it eliminates conventional power train losses. A steam engine needs no power train and, unlike the internal combustion engine, the external combustion engine torque output is maximum even when starting from a stop. Thus, it is estimated that a steam engine of 500-horsepower is the equivalent of a 1000-horsepower internal combustion engine.

The way I read that statement is that he's saying the torque characteristics of a steam engine make it the practical equivalent of an IC engine of twice the horsepower.

[Queeg]

The way I read that statement is that he's saying the torque characteristics of a steam engine make it the practical equivalent of an IC engine of twice the horsepower.

Hence the reason why Heavy trucks use diesel engines, low rpm torque is king. They want traction not high speed incremental gains. Electric motors have similar bonuses, esp now control systems can manage and feather the hard start.

I like Steampunk stuff, some of it looks reall great (like the steam powered the flying "aerospacecraft" from Mutant Chronicles movie). But you have to sacrifice some practicality and just accept it for what it is - a bit of rollicking fun.  A tank using steam power will be big and slower. Because it's big you need a larger gun to make it worthwhile, then a bit more armour etc etc etc

[dy031101]

Guess I'm looking at more of a steam-powered Löwe...... 

[Queeg]

Guess I'm looking at more of a steam-powered Löwe...... 

Lol ...... probably more of a Maus, which looks like a train incidentally. The Germans didn't waste any money on the asthetics part of that project ......

[dy031101]

The scaled model of a steam-powered tank proposal in 1964 mentioned in article posted by Rickshaw.

It uses a pair of steam turbines though (whereas the article actually places more emphasis on steam engines that do not employ turbines), each turbine delivering 250hp at 24000rpm.  It is claimed that, including a three-to-one reduction gear, the turbines in full size were expected to be no more than 9in by 18in in size.

EDIT: Re-phrased as pointed out by jcf.

[elmayerle]

So we perhaps go the other way, a steam-powered, steam-punk Bolo?  Controlled by a steam-driven babbage engine?

[jcf]

It uses a pair of steam turbines though (whereas the article actually places more emphasis on just steam engines), each turbine delivering 250hp at 24000rpm.  It is claimed that, including a three-to-one reduction gear, the turbines in full size were expected to be no more than 9in by 18in in size.

A steam turbine is a steam engine, the difference is that instead of the steam moving piston(s)
in cylinders the steam spins a series of discs.

[Rickshaw]

Just let me throw another example of what can be achieved with steam - the British Steam Car Challenge which raised the land speed record for steam powered vehicles to 148mph over a kilometre course.

While not necessarily a practicable design for an Armoured Fighting Vehicle (AFV) it does indicate that steam has been under-rated as a power source for vehicles for a long time IMO.

[jcf]

Just let me throw another example of what can be achieved with steam - the British Steam Car Challenge which raised the land speed record for steam powered vehicles to 148mph over a kilometre course.

While not necessarily a practicable design for an Armoured Fighting Vehicle (AFV) it does indicate that steam has been under-rated as a power source for vehicles for a long time IMO.

True, but the old record of 127.659 mph stood for 103 years. 

[Rickshaw]

Yes but it could be claimed that was because of the VICC (Vast Internal Combustion Conspiracy)(tm)!! 

[AndyJ]

Something I've been playing around with since 2010 is a steam powered Landcrawler designed to fight Martian war-machines in WWoW II.

http://beyondthesprues.com/Forum/index.php?topic=2579.0

Power was definitely something that was a design constraint and although I tried to keep it as feasible as possible there just had to be design fudges. also it's supposed to be a fun build, not an engineering proposal 

[dy031101]

Something I've been playing around with since 2010 is a steam powered Landcrawler designed to fight Martian war-machines in WWoW II.

http://beyondthesprues.com/Forum/index.php?topic=2579.0

Power was definitely something that was a design constraint and although I tried to keep it as feasible as possible there just had to be design fudges. also it's supposed to be a fun build, not an engineering proposal 

Did not notice this one until now...... wow......

Hey hey hey, is anyone willing to venture a guess on, if I want to shrink it to using regular tank armaments (a 105mm gun, for example), how much smaller the engine deck would be?

[Old Wombat]

I'll give it a guess.

Assuming a single QF 4" (or 4.7") Mk. I/II in the turret;

The turret would have approximate (LxWxH) dimensions of 4.5m x 3m x 1.5m (in a more compact WW1/2 era configuration)

The engine deck is approximately 1.2x the length of the turret & about 1.05x the width.

So;

(1.2 x 4.5m) x (1.05 x 3m) = 5.4m x 3.06m (or approx. 5.4m x 3.1m) = 16.524m² (or 16.74m²)

Using the more approximate size;

In 1/35th: 15.43cm x 8.86cm = 136.70cm² (which seems to be about the size of AndyJ's build)

In 1/48th: 11.25cm x 6.46cm = 72.68cm² (which I think should be AndyJ's scale)

AndyJ didn't mention his scale in the original Steam Landcrawler MkI thread, so I'm guessing it's 1/35th scale-o-rama'd to 1/48th (although the StuIG 33B he said was in the same scale looks to be 1/35th, in which case, Andy, your current turret is probably slightly undersized for the twin 8" guns).

:)

Guy

[AndyJ]

I'll give it a guess.

Assuming a single QF 4" (or 4.7") Mk. I/II in the turret;

The turret would have approximate (LxWxH) dimensions of 4.5m x 3m x 1.5m (in a more compact WW1/2 era configuration)

The engine deck is approximately 1.2x the length of the turret & about 1.05x the width.

So;

(1.2 x 4.5m) x (1.05 x 3m) = 5.4m x 3.06m (or approx. 5.4m x 3.1m) = 16.524m² (or 16.74m²)

Using the more approximate size;

In 1/35th: 15.43cm x 8.86cm = 136.70cm² (which seems to be about the size of AndyJ's build)

In 1/48th: 11.25cm x 6.46cm = 72.68cm² (which I think should be AndyJ's scale)

AndyJ didn't mention his scale in the original Steam Landcrawler MkI thread, so I'm guessing it's 1/35th scale-o-rama'd to 1/48th (although the StuIG 33B he said was in the same scale looks to be 1/35th, in which case, Andy, your current turret is probably slightly undersized for the twin 8" guns).

:)

Guy

Oh yeah, it's 1/35 scale, which is of course The One True Scale for anything on tracks 

There are a lot of scale issues with this build what with the underpowered propulsion*, the somewhat cramped turret and the woefully inadequate condenser array  However, these are all the typical sorts of self-imposed problems that plagued British armour design up until the Centurion, so I'm sort of following a fine tradition there...

I did toy with the idea of working this to 1/43 scale as there are a lot of steampunk type figures in that scale but I just couldn't face working outside of my 1/35 scale comfort zone. Although it may not be too late to reconsider that decision...

*The steam generation and turbo-generators might not be too far outside of what would be required as this was designed with assistance from my sister who designs these things as her day job, although usually nuclear powered. Estimated power output from a single oil-fired Babcock water tube boiler supplying two 500 kW Parsons HP turbo-generators and two 250 kW Parsons LP turbo-generators would give a max output of 1.5 MW supplied to two traction motors. Or in old-money, 1200 hp to power something with a design weight of 150 - 200 tonnes, it would likely be quicker than the Maus, although TBH my 85 year old Mum would be quicker than the Maus 

[Old Wombat]

 

Of course 1/35th is the One True Armour Scale! (D'you hear that Airfix! Helicopters, too, dammit! )

So, all dy031101 needs to do is fit a QF 4"/4.7" Mk. I/II (maybe 2) in a similar sized turret & he's cooking with gas!

:)

Guy

(Note: I chose the QF 4" Mk. I/II & the QF 4.7" Mk. I/II because they were all available in the 1900-1910 time line. )

[dy031101]

So, all dy031101 needs to do is fit a QF 4"/4.7" Mk. I/II (maybe 2) in a similar sized turret & he's cooking with gas!

(Note: I chose the QF 4" Mk. I/II & the QF 4.7" Mk. I/II because they were all available in the 1900-1910 time line. )

Well actually what I'm looking for is more of a "Panzer Löwe with steam engine" rather than a 1900s land corvette...... so yup, single-gun tank turret and other regular tank stuff.

But Parsons steam turbo-generators and adopted marine boilers?  F**k yeah! 

[Old Wombat]

The other reason I chose those guns is that they fit into the 105mm-ish bore range which you mentioned.

You could always use later Marks of the QF 4" or 4.7" for a WW2 version.

The crunch is that the engine deck would actually remain about the same size, maybe a few cm/in difference due to design differences.

:)

Guy

[AndyJ]

So, all dy031101 needs to do is fit a QF 4"/4.7" Mk. I/II (maybe 2) in a similar sized turret & he's cooking with gas!

(Note: I chose the QF 4" Mk. I/II & the QF 4.7" Mk. I/II because they were all available in the 1900-1910 time line. )

Well actually what I'm looking for is more of a "Panzer Löwe with steam engine" rather than a 1900s land corvette...... so yup, single-gun tank turret and other regular tank stuff.

But Parsons steam turbo-generators and adopted marine boilers?  F**k yeah! 

If you can get hold of a copy HMS Dreadnought (Anatomy of the ship), it has some excellent diagrams of the steam systems and turbines. Gave me good inspiration for the one I used on the landcrawler. Be prepared for an inordinate amount of space to be used up on your steam Löwe though, so perhaps a longer hull with extra set or two of wheels? I used a Mörser Karl hull and I think even that limited the amount of stuff I could cram in.

[Rickshaw]

I think and E-75 or even an E-100 hull would be more suitable.  Perhaps make a bit wider by splicing some plasticard down the middle.  With the E-100, I'd perhaps use a Smallturm from a Panther turret to give even more room (with an 88mm L/71).  This assumed advanced boiler technology and engine designs with advanced fuels are used.

[dy031101]

Assuming we are not limited to German-made weapon...... what's the minimum tank gun available to Western Europe that can be effective against a T-54?

[Rickshaw]

105mm Vickers L7.  It was developed for that purpose afterall.  I supposed if you could up the MV on the US 90mm T54 (and derivatives) or the 20 Pdr, it would work.  However, chamber volume becomes a limiting factor.

When the Soviet T54 took the wrong turning into the British Embassy in Budapest in 1956, they realised they needed a much higher velocity to penetrate it's glacis.  It was one of those God Sends which determined the course of NATO's armament procurements.

[tankmodeler]

The key things that really limit the usefullness of steam to power vehicles is the power supply and the steam pressure prior to entering the first turbine.

If you can posit something like an Edgar R. Burroughs "9th Ray" to generate the steam without having to carry coal and fireboxes, you then can concentrate your available volume on things like the wall thickness of the boiler & piping to get the pressure waaaaay up. If you have the "9th ray" sort of limitless power, you can also dispense with things like regenerators, intercoolers and condensors that also take up large amounts of volume and mass.

If you are looking at an Edwardian era Burroughs-esque sort of Science Fantasy, then this can all still hold together. Ya just have to wisely pick what parts of the real universe you choose to ignore.  :)

Paul

[dy031101]

Another source of aesthetic inspiration......