German Minigun?

[davebender]

Fokker-Leimberger - Wikipedia, the free encyclopedia
Apparently 1916 Germany had a 7.92mm minigun prototype capable of firing 7,200 rounds per minute. Did Germany or anyone else pursue development of a minigun during the 1930s? If you could make it work such a weapon could replace all 8 wing mounted .303 machineguns in the Spitfire and Hurricane. Or perhaps a .50cal version for U.S. fighter aircraft.

 

[johnbr]

Wow you find something out every day.

 

[davebender]

http://www.theaerodrome.com/forum/o...looking-pics-siemens-machine-guns-fitted.html
A prototype Siemens minigun was installed on a Jasta 58 Albatross fighter aircraft. Apparently at least one kill was scored using this WWI era aircraft minigun.


Gebauer Machine Gun 1918.M
An Austrian weapon.
Franz Gebauer - Wikipedia, the free encyclopedia

In 1917 Gebauer submitted his first twin-barreled motor driven machine gun design to his commanding officer and received approval to make prototypes. The first two were not successful, but the third improved design performed flawlessly on its trial in June 1918 at Aspern, near Vienna. The prototype was installed on an Aviatik D.II aircraft, flown by Colonel Benno Fiala.

The Gebauer 1918.M (Gebauer Motorgéppuska 1918.M) weighed 21 kg (46 lb) and could fire at a rate of 25 rounds per second, or 1500 rounds per minute, 4 times faster than the Schwarzlose, which could only achieve 6.25 rounds per second in similar conditions. The first 100 guns were ordered by the military in September 1918, the Solux Company of Vienna providing additional monetary support. The 100 guns were completed in October 1918, but the Armistice prevented actual combat testing

October 1918 production date.
Weapon perform flawlessly on trials during June 1918.
21 kg Weapon weight.
1,500 rounds per minute.
Franz Gebauer moved to Hungary after WWI. Some development work continued in secret (to evade Entente inspectors) and some weapons were produced. However post-WWI Hungary did not have the resources to fully develop this excellent weapon.

1935 GDP (measured in millions of 1990 American dollars).
22,204 Hungary.
275,496 Germany.

Germany began serious rearmament during 1935. The German economy was about 12 times as large as Hungary. Furthermore some German firms like Siemens had minigun experience of their own. Why didn't the Luftwaffe and/or Heer jump on minigun development?

 

[Gixxerman]

Really interesting find Dave.
I've wondered how come a design like the Gattling based guns came so late, I had no idea they had been tried so early.
I always imagined reliability was the reason but obviously not necessaily.

Maybe it was the driving tech, maybe electricly driven guns were the key that tech was beyond the time (in terms of size weight)?
Perhaps sighting issues would have made that sort of ammunition expenditure look vastly expensive for little gain?
Set against the weight of carrying all that ammo?

I can't imagine anyone deciding, after a very short testing period, to (as now) go to more than 1 mini-gun - or on ground attack one bigger Gattling design.
Where would you mount it on an Me109 or FW 190 and could the airframe take the stresses of it?
I'm not saying it couldn't be done but it's such a leap from then convention it's not hard to see why designers might prefer, in the case of the Brits, 8 seperate guns or the Germans a mix of cannon and machine guns, to 1 or 2 mini-guns.
Less chance of failure too?

A rotary 20mm or 30mm might be a different case but they're huge and have pretty big ammo drums and motors.

....if you had air superiority maybe you could afford a Ju52 magic dragon!? But then again dense AA, not uncommon in WW2 esp later in Russia might make that one scary proposition for the crews?

 

[davebender]

This would be a good place to start.

A 2cm rotary cannon firing at 1,800 rpm would almost certainly be smaller, lighter in weight and more reliable then the historical Flakvierling 38. It would probably also have a smaller crew size.

After gaining experience with a light flak weapon the Luftwaffe would continue development towards making an aircraft mounted 2cm cannon. Meanwhile the Heer could work on a 3cm version suitable for light tanks and armored cars.

 

[Shortround6]

I've wondered how come a design like the Gattling based guns came so late, I had no idea they had been tried so early.
I always imagined reliability was the reason but obviously not necessaily.

Maybe it was the driving tech, maybe electricly driven guns were the key that tech was beyond the time (in terms of size weight)?
Perhaps sighting issues would have made that sort of ammunition expenditure look vastly expensive for little gain?

A big problem was feeding the guns. Until the development of servo motors that could proportion the feed rates to the guns needs (and it takes a significant amount of time to spin up a Gatling gun to full speed. Around a 1/2 second or so which in air combat is significant) keeping the belt moving was a problem. It is one thing to move a belt of rifle caliber ammunition at even 20 rounds a second, it is quite another to move the larger, heavier, wider spaced cannon ammo at a much higher speed. Now try and do it while pulling 4 'G's or better. a problem that plagued more than one gun in WW II.

 

[davebender]

I'm under the impression rotary cannon are designed to be spun up prior to firing. Perhaps when you switch on the gunsight.

 

[Shortround6]

I'm under the impression rotary cannon are designed to be spun up prior to firing. Perhaps when you switch on the gunsight.

"Another criticism is that despite its high rate of fire, the Gatling-type weapon is hampered by the time it takes for the weapon to spin up to its maximum rotation speed (about 0.5 seconds). As a result, a one-second burst only fires about 70-75 rounds, which some experts feel is not enough of an advantage over revolver cannons like the ADEN/DEFA 30 mm weapons to justify the additional weight and complexity. To overcome this shortfall, the M61A2, with its lower inertia can be powered by a hydraulic motor with 5,000 P.S.I. (34 MPa) of hydro power instead of the 3,000 lbf/in² (21 MPa) previously used on the F-15 Eagle and F-16 Fighting Falcon."

You have the power requirement, which could be up 26 hp if I recall right, not something you want to feed anytime the gun sight is switched on. You also need a feed that could be turned on and off independent of the gun spinning/cycling and could come up to the 100 rounds per second instantly.

 

[magnu]

If impractical for fighters such a weapons system could have been used for ground attack
aircraft and been very effective.

 

[gjs238]

If impractical for fighters such a weapons system could have been used for ground attack
aircraft and been very effective.

Or for shooting down bombers (?)

 

[davebender]

M61 Vulcan - Wikipedia, the free encyclopedia
112kg. Weight of 20mm M61 Vulcan rotary cannon.

MG 151 cannon - Wikipedia, the free encyclopedia
252kg. Weight of 6 x 20mm MG151/20 cannon.

Some WWII German aircraft dedicated to the bomber killer role were armed with up to six MG151/20 cannon. Replacing them with a single rotary cannon should save weight. Put the rotary cannon in the nose of a Me-110, Ju-88 or Me-262.


A German rotary cannon gives RLM another reason to consider placing the Fw-187 into mass production during 1940 as the weapon will fit in the aircraft nose. That gives the Luftwaffe a day fighter with many times the firepower of a Me-109E.

 

[Gixxerman]

Yeah but Dave, it's not just the gun, those vast 'bins' of ammo must weigh a hell of a lot.

In an era of much less accurate fire how much more would be needed for a weapon capable of spewing out, well lets say they got a 20mm version reliable at 2500 - 3500 rpm (sound reasonable?).

(and presumably we also now have years spent developing these things, our planes benefit from much lighter shell cases, more effective explosives and lighter propellants?)

Not saying I have the slightest idea whether it's feasible or not but those strike me as fairly obvious points open to question.

A German rotary cannon gives RLM another reason to consider placing the Fw-187 into mass production during 1940 as the weapon will fit in the aircraft nose. That gives the Luftwaffe a day fighter with many times the firepower of a Me-109E.

lol, you sure have a thing for that FW dave!

 

[davebender]

A WWII era German 2cm rotary cannon is likely to use the same ammo as the MG151/20. It will weigh the same whether you are feeding 1 rotary cannon or 6 x MG151/20 cannon.

 

[Jerry W. Loper]

Fokker-Leimberger - Wikipedia, the free encyclopedia
Apparently 1916 Germany had a 7.92mm minigun prototype capable of firing 7,200 rounds per minute. Did Germany or anyone else pursue development of a minigun during the 1930s? If you could make it work such a weapon could replace all 8 wing mounted .303 machineguns in the Spitfire and Hurricane. Or perhaps a .50cal version for U.S. fighter aircraft.

A gun with a cyclic rate of fire of 7,200 rounds per minute would fire 1,800 rounds in 15 seconds, which begs the question of how much ammo a plane with this gun would carry.

 

[davebender]

That was an experimental weapon. I would expect more like 2,000 rounds per minute for a WWII era production weapon.

 

[The Basket]

The MG 42 was criticized for having too fast firing rate.

Having a weapon is one thing...having to feed the monster is another.

 

[davebender]

Criticized by who? The people being shot at? I've never read any German accounts critical to the MG42.

 

[Shortround6]

That was an experimental weapon. I would expect more like 2,000 rounds per minute for a WWII era production weapon.

then what is the point?

Unless the gun is lighter than three MG 151s it doesn't win the weight to firepower contest, Being unbale to mount the gun with barrel inside the engine block like a normal engine mount gun or even a revolver cannon means the entire gun (including the length of the barrels has to be behind the engine, not good in a single engine fighter. Twin engine fighter can simply mount 3 or more conventional guns for the same fire power in a fuselage mount.

If the rotary (Gatling) gun jams the plane is out of the fight. If one normal gun out of 3 or more jams the plane is still in the fight.

The rotary/Gatling has to have a high enough rate of fire to over more firepower than an equivalent weight of normal guns. Then you have the feed problem. You have to move the belt (under 3 or more "G"s) 3 or 4 or 5 times faster than the belt for a conventional gun moves.
yes the problem was solved but getting the feed and ejection of spent cases and links is probably as big a problem as getting the gun to function in the first place. Americans 'solved' the problem by using a link less feed that but the empties back in the magazine. Another ammunition chute with it's own servo motors and sprockets to take care of the empties.

 

[Shortround6]

Criticized by who? The people being shot at? I've never read any German accounts critical to the MG42.

Ever shoot one?

 

[davebender]

Perhaps that is the reason Germany opted for the M213 revolver cannon over a rotary cannon. They wanted a weapon which could fire through a prop shaft. Until the revolver cannon was ready for mass production the MG151/20 worked good enough.