Trench Compressed Air Guns?

Delta Force

Banned
It seems that something akin to a paintball gun could have found a niche in trench warfare. Modern recreational paintball guns are capable of firing 3 gram projectiles to speeds of 120 meters per second or higher (capped to 90 meters per second for field play), giving them a kinetic energy equivalent to .22 CB rounds. They can also achieve rates of fire ranging from 8 rounds per second with gravity feed mechanisms to 20 with motorized feed systems (up to 30 with electronic feed mechanisms) and carry hundreds of shots. The systems are low pressure relative to a firearm and can use plastic and other components not possible for use with a firearm, although the tanks must use compressed carbon dioxide, nitrogen, or propane propellant.

Although nothing similar to a modern recreational paintball gun existed around the time of World War I, there were historical compressed air weapons such as the Girandoni air rifle. Compressed air guns would also have the advantage of being able to use ball shot (otherwise of limited use for the war effort) and no powder, and they could use materials unsuitable for building high pressure weapons (apart from the propellant canisters).

Could compressed air guns have been of use in World War I, or would it be better to produce more conventional weapons?
 

trurle

Banned
May be. Before infantry in WWI was adequately supplied with mortars, they tried a lot of improvised mechanical launchers. The pressurized air launcher just required some precision components not easily available to infantry units IOTL (valves, barrels) and had pretty low performance. So it can be improvised weapon only. Well, i can image the pressured-air grenade launcher as an upgrade for the air bottle of the anti-gas mask.
IOTL, anti-gas filters were selected instead of air bottles. May be air bootles can be mass-produced if Germans chemical warfare usage starts right from phosgene instead of chlorine?
 

Insider

Banned
There were pneumatic mortars in use in WWI, however ASG equipped infantry would have to turn back and rearm once they defeat the enemy in their trench, to advance further, or they would found themselves against terrible odds.
5128599254_ff151cd04a_b.jpg
8_cm_Luftminenwerfer_M15.jpg

15cmM15BelgradeFoti2.jpg
 
There is the 60mm Brant pneumatique mortar
500 were built by 1917 and 3000 other were ordered (I do not know how many were delivered) as well as 1 million round
 
And then there were the biggest spud guns ever made by Captain Edmund Zalinski, 15" 1150 pound shells filled with dynamite
 
What about smaller paintball gun type weapons?

Seems like a solution in search of a problem to me. It was certainly possible to build airguns before WW1, and even to build airguns that had a decent chance of killing someone. The problem is that chemical propellant weapons were much much better at that, and in this context there isn't much incentive for showing up with second best. I don't recall hearing about any of the combatants being short of firearms, so fielding airguns would be an act of will, not desperation. Which brings us back to the original question - why bother? What is the problem to which airguns are the answer, and firearms are not a better answer?
 

Delta Force

Banned
Seems like a solution in search of a problem to me. It was certainly possible to build airguns before WW1, and even to build airguns that had a decent chance of killing someone. The problem is that chemical propellant weapons were much much better at that, and in this context there isn't much incentive for showing up with second best. I don't recall hearing about any of the combatants being short of firearms, so fielding airguns would be an act of will, not desperation. Which brings us back to the original question - why bother? What is the problem to which airguns are the answer, and firearms are not a better answer?

To do what? They can't match firearms for effectiveness and are as expensive to manufacture.

Airguns can hold a huge amount of shots relative to conventional weapons, and without requiring complicated and often unreliable high capacity magazines. They can also make use of ball shot production capabilities and do not require strategic materials such as powder propellant and brass shells.
 
Airguns can hold a huge amount of shots relative to conventional weapons, and without requiring complicated and often unreliable high capacity magazines. They can also make use of ball shot production capabilities and do not require strategic materials such as powder propellant and brass shells.
They require precision valves and other parts and high strength reservoirs for compressed gas. They're also far less dangerous than firearms with much lower projectile energies and inferior accuracy. While airguns have had a limited niche during a few periods in history (i.e. the Windbüchse before repeating firearms and for clandestine use before sound moderators) they've never been common weapons for very good reasons.

As for "a huge amount of shots relative to conventional weapons, and without requiring complicated and often unreliable high capacity magazines" how is this possible? Regardless of the type of ammunition it will need a magazine of some sort to feed projectiles/rounds to maintain any useful rate of fire.
Spherical projectiles were supplanted by conical for the excellent reason that they have vastly inferior ballistics.
 

Delta Force

Banned
They require precision valves and other parts and high strength reservoirs for compressed gas. They're also far less dangerous than firearms with much lower projectile energies and inferior accuracy. While airguns have had a limited niche during a few periods in history (i.e. the Windbüchse before repeating firearms and for clandestine use before sound moderators) they've never been common weapons for very good reasons.

As for "a huge amount of shots relative to conventional weapons, and without requiring complicated and often unreliable high capacity magazines" how is this possible? Regardless of the type of ammunition it will need a magazine of some sort to feed projectiles/rounds to maintain any useful rate of fire.
Spherical projectiles were supplanted by conical for the excellent reason that they have vastly inferior ballistics.

A paintball gun can achieve 8 rounds per minute with a gravity feed system, and even higher with motorized systems (which would probably not have been infantry portable in World War I). The magazine would be a simple container, even a funnel could suffice if not for the issue of spilling rounds or getting grime in the mechanism.

The ballistics would be poor, but it wouldn't matter in a trench. A heavy coat or armor could help defend against the shots, but the airguns would be able to deliver such a tremendous amount of sustained fire that even non-penetrating shots could prove incapacitating.
 
A paintball gun can achieve 8 rounds per minute with a gravity feed system, and even higher with motorized systems (which would probably not have been infantry portable in World War I). The magazine would be a simple container, even a funnel could suffice if not for the issue of spilling rounds or getting grime in the mechanism.

The ballistics would be poor, but it wouldn't matter in a trench. A heavy coat or armor could help defend against the shots, but the airguns would be able to deliver such a tremendous amount of sustained fire that even non-penetrating shots could prove incapacitating.
I disagree utterly over this.
Firstly a gravity feed system will only work when feeding downwards, anything more generally useful will be as complex as the feed system for a firearm.
Secondly the airgun still needs precision valves and other components stressed to take the firing pressures. It's extremely rare for airguns to achieve supersonic velocities due to the pressure problems.
Thirdly assuming you're not merely firing gel capsules the ammunition will need to be metal spheres (unless you're postulating conical projectiles which would negate your funnel idea); either they'll need to be precisely made (introducing complexity), soft enough to be deformed by barrel contact (introducing fouling and wear) or the windage will reduce the already poor velocity and accuracy.

Your suggestion of sustained fire proving useful applies just as much to firearms, which would be far more effective and easier to integrate into existing logistics; invent the sub-machine gun a few years early.

What is the envisaged role for this weapon? A poor version of a machine gun? A shoulder fired rifle?
 

Delta Force

Banned
Firstly a gravity feed system will only work when feeding downwards, anything more generally useful will be as complex as the feed system for a firearm.

Gravity feed is quite workable with paintball guns.

Secondly the airgun still needs precision valves and other components stressed to take the firing pressures. It's extremely rare for airguns to achieve supersonic velocities due to the pressure problems.

The velocity would definitely be subsonic.

Thirdly assuming you're not merely firing gel capsules the ammunition will need to be metal spheres (unless you're postulating conical projectiles which would negate your funnel idea); either they'll need to be precisely made (introducing complexity), soft enough to be deformed by barrel contact (introducing fouling and wear) or the windage will reduce the already poor velocity and accuracy.

The ammunition would be large shotgun pellets or smoothbore musket balls to take advantage of civilian infrastructure and stocks.

Your suggestion of sustained fire proving useful applies just as much to firearms, which would be far more effective and easier to integrate into existing logistics; invent the sub-machine gun a few years early.

What is the envisaged role for this weapon? A poor version of a machine gun? A shoulder fired rifle?

It would be akin to a light machine gun or submachine gun for trench assaults, although mainly for suppression due to its low stopping power (unless shooting musket balls).
 
Gravity feed is quite workable with paintball guns.
But hardly reliable, especially in an automatic weapon.

The velocity would definitely be subsonic.
OK, assuming a velocity of ~200m/s (wildly optimistic I know) and a mass of 4 grammes (9mm lead pellet) that's 80 joules; lower energy than a .25 Auto round and about one-fifth of a 9mm Parabellum. Horribly poor ballistic coefficient so a useful range of <50m (and that's being optimistic) with poor accuracy (especially with an unrifled barrel).

The ammunition would be large shotgun pellets or smoothbore musket balls to take advantage of civilian infrastructure and stocks.
Which means the barrels et cetera would need to be especially built.

It would be akin to a light machine gun or submachine gun for trench assaults, although mainly for suppression due to its low stopping power (unless shooting musket balls).
Why not use shotguns or sub-machine guns?

FYI the only airgun to see significant military use was the Girandoni Windbüchse of the late eighteenth century. It managed to fire a projectile with around 200J muzzle energy from a reservoir at around 5.2MPa pressure that allowed for thirty shots and a useful range of 100-120m. It was known to be expensive, unreliable and prone to damage.
Now assuming (all very optimistic) a pressure of around 12MPa for your trench weapon (better materials) and a corresponding velocity of ~250m/s and an 12 gramme ball that's 300J, comparable to a .38 Special round.
Mass production of converted semi-automatic pistols with large magazines and selective-fire capacity would be cheaper, simpler and more militarily useful.
 
I think the much shorter range of intra trench warfare could make this viable but the projectiles would need to be at least 0.50in caliber to make it worth while. The question is, could you carry a large enough tank to produce enough high pressure air to give enough shots at a high enough velocity to make it worth while. With late 19th C early 20thC technology it's not viable.
 
I think the much shorter range of intra trench warfare could make this viable but the projectiles would need to be at least 0.50in caliber to make it worth while. The question is, could you carry a large enough tank to produce enough high pressure air to give enough shots at a high enough velocity to make it worth while. With late 19th C early 20thC technology it's not viable.
Let's guesstimate some numbers. A 12.7mm lead ball would weigh around 12 grammes or 180 grains; assuming a velocity of 257m/s that's a muzzle energy of approximately 450J (or 330fl.lb). That's comparable to a 9mm Parabellum round.
Now let's look at a reservoir (and assume an isothermal case to simplify matters); the maximum energy storable is

Reservoir Pressure * Reservoir Volume * ln(Reservoir Pressure/Ambient Pressure)

Assuming an operating pressure of 12MPa (1,750psi or 120 atmospheres) which should be possible with 1900ish steels, a reservoir volume of 5 litres this gives us:

12 * 0.005 * ln (120) or 287kJ.

Given an extraction/conversion efficiency of 20% (optimistic) this would be sufficient to fire 128 pellets.

The pressure vessel will weigh around 10kg (roughly) for 1900 era alloys and the air 0.6kg. This will be able to fire around 90 shots. The weapon will weigh (based on the few moderately powerful airguns of the era) 5-6 kg so the entire weapon will weigh
5.5kg (weapon) + 10kg (reservoir) + 0.75kg (air) + 1.54kg (120 pellets) + 0.3kg (magazine) = 18.1kg
If there's a hose connection for the reservoir efficiency will be even lower and the weight greater.

All rather rough-and-ready but not too far from reality.

To compare a Lewis gun weighs 13kg unloaded and (IIRR) the 97rd magazine weighed about 4kg loaded, about the same. Of course the .303 (or whatever calibre) rounds would be far more accurate, longer ranged and more deadly. Plus reloading the Lewis would require removing the empty pan-drum and replacing it, not connecting the weapon to an air-compressor and pouring in lead balls.
 
A compressed air trench mortar has the advantages of surprise and low acceleration.

IIRC, it was quiet enough compared to a regular weapon to catch entrenched squaddies by surprise.
At first...

The low acceleration certainly lent itself to chemical weapons...

Either way, you'd need a well-settled trench system, with a perilously narrow 'no mans land'.

I think the squaddies would have happily traded the big lump for a hot meal and more flares !!
 
Top