1935-45: alternative airborne weapons

Near Fantasy desire?

1.1" in a three barrel Gatling in the nose for a Grumman F5F
In Metric rather than Freedom Units, that cartridge is designated as 28x199mm with 823m/s velocity, with a 416 gram HE-T projectile with 17 grams of Comp D burster. 36000psi working pressure
I like that idea. I had been thinking about adopting the 1.1" gun as a traditional single barreled aircraft cannon. My Gatling idea is for the 50. cal MG. The P-38 would also be a good mount for either 1.1" gun or either Gatling gun. P-70's and P-61's as well. Hmm, what about the P-39 and P-63?
 
Rockets would have been devastating against bombers if (and it's a big if) the rocket armed fighters could outclimb and outpace the bombers, so they could be attacked from above and behind.
But if you can get a fighter in that position, why not use cannon (as per Bf 110, Whirlwind) where you have some chance against fighters as well and don't slow the climb rate with drag from rockets.
Also, pre-war and early war bombers were fast enough to make fighter interception difficult without radar and integrated air defence systems. Add the influence of Douhet's 'Bomber will always get through' mindset and it's hard to see an early driver for rockets.
 
I like that idea. I had been thinking about adopting the 1.1" gun as a traditional single barreled aircraft cannon. My Gatling idea is for the 50. cal MG. The P-38 would also be a good mount for either 1.1" gun or either Gatling gun. P-70's and P-61's as well. Hmm, what about the P-39 and P-63?
Sounds very promising
Wasn't the P39 in some theatres rearmed with 20mm or 23mm cannon which had higher velocity and therefore better accuracy though less destructive than the original 37mm [1]. The 0.9" should work well there.
Was there a decent 30mm+ candidate (including a better 37mm) that could have been used?
[1] 20mm that hits is always more destructive than 37mm that misses.
 
My preferred PoD for this is to have Colt only offer their concept for scaling up their Browning aircraft MG to .90 caliber when the USAAF comes calling asking for concepts for autocannons in 1933, rather than the OTL inclusion of the concept for a "cheaper" long-recoil option which led to this OTL project.


I don't know about the French but the Belgians built yet another enlarged version of the Browning aircraft machine gun in 13.2mm that seems to have been quite good.

I'm continuously amazed at how everyone used the Browning in rifle calibers as their main prewar aircraft gun, yet only the Japanese seem to have made any effort to scale it up to an autocannon!

Moving away from Browning derivatives, the Soviet experiments with recoilless rifles as bomber destroying armament, such as the Tupolev I-12, fascinate me. If they could figure out some kind of feed system they might have an interesting tank buster on their hands. (In particular, although I'm unsure whether the guns they were trialing were rifled or not, recoilless rifles might offer some serious accuracy advantages over rockets, especially in the 1940s.)

Rockets, too, are an obvious example of something that was popular among anti-aircraft gun inventors in the interwar period, and placed on aircraft during the war, but which weren't really used for either air-to-air or air-to-ground use pre-war (the Soviets excepted). Given how effective rockets proved for general ground attack duties, having some designed, optimized for air-launched accuracy, and produced in numbers before the outbreak of war would seem to offer a lot of advantages.
Rockets are a good choice for earlier use. "It was during the Battle of Britain that the RAF used its first air-to-air rockets. Skuas, Defiants, Blenheims, and the RCAF F3F's were the first rocket carriers, while Spitfires and Hurricanes waded in with their guns. On the other side, Me-110's were removed from the escort role, switching to low level raids on airfields and shipping with rockets and guns."

In the Pacific, the IJA Ki-45 Toryu was the first Japanese fighter to use anti-air and anti-ship rockets...
 
Was a anti-runway bomb (as we know them) possible in the 1939-1942 range of development? I realize with a lot of grass field back then, that might not be as disruptive as they are now against paved fields.

I don't know about other nations, but the US Army Air Corps did buy a batch of something like that in the 1920s. I'd have to search for the details. According to Gambles 'Fortress Rabaul' Gen Kenny requested and got for his 5th AF in 1942 a large part of those which were still in storage in the US.
 
An earlier use of guided bombs by Germany. Have Japan and/or Italy develop guided weapons and field them during the war. The guided bombs would be more important to the Axis than the Allies, I think. Sweden could be another candidate, though that would mean spending money on that research project.
 
The MG 151 series were excellent: any chance that the American reverse-engineered .60-cal derivative could've turned out better?

During World War II the US Army produced the .60-caliber T17, a reverse-engineered copy of the German MG151 chambered for an experimental anti-tank rifle round. A speculative order of 5,000 T17 guns was placed but only around 300 of them were built. However none saw service despite the availability of 6 million rounds of .60 caliber ammunition.[17] Almost one million rounds were fired during the T17 testing program. The main US version produced, the T17E3, was made by Frigidaire; it weighed 134 lb (61 kg) and had a rate of fire of only 600 rounds per minute. Further refinements led to the T39 and T51 versions, but these also did not enter service.[18]

AmmunitionEdit

A cartridge originally based on an armor-piercing round designed in 1939 for use with the experimental T1 and T1E1 anti-tank rifles. It was cancelled in 1944 when it became clear that modern tanks had armor too thick to penetrate with a heavy rifle cartridge. Developments showed that shaped-charged rifle grenades and rocket launchers were the future of infantry anti-tank weapons and the anti-tank rifle concept was abandoned.

Much like the British attempts to turn their stocks of obsolete .55 Boys anti-tank cartridges into a native-designed heavy machinegun cartridge, the .60-caliber cartridge was repurposed as an auto-cannon cartridge to succeed the older .50 Browning. The ammunition and the T17 cannon were produced from 1942 to 1946 but never proved a substantial improvement over the .50 Browning and the M2HB and M3 heavy machineguns. The cartridge was later shortened and necked-up to produce the 20x102mm Vulcan autocannon round.

  • .60 Armor-Piercing (15.2 x 114mm T1E1) - A 1180 grain (76.5 gram) kinetic penetrator projectile with a velocity of 3,600 feet per second (1,100 m/s) for a muzzle energy of over 34,000 ft./lbs. (46 kilojoules).[19][20]
  • .60 T32 Ball (15.2 x 114mm T17)
 
Weren't a couple of the escort carriers modified (or to be modified) for launches? I remember something along those lines.
A variety of ships had experimental launchers installed. All that testing with the JB-2 served the Regulas missile development program. A submarine launched version was tested as well.
 
Electric drive on tanks. The railroads industry had worked out the details on electric drive or transmissions & had a wide variety in production. the US Army did in 1943 spec one of the T20 prototype variants for a electric transmission. Designated the T23 a limited production of 250 was completed in mid 1945. Since the earliest electric drives existed in the late 19th Century for urban & interurban railways the potential was there.
 
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Rockets would have been devastating against bombers if (and it's a big if) the rocket armed fighters could outclimb and outpace the bombers, so they could be attacked from above and behind.
But if you can get a fighter in that position, why not use cannon (as per Bf 110, Whirlwind) where you have some chance against fighters as well and don't slow the climb rate with drag from rockets.
Also, pre-war and early war bombers were fast enough to make fighter interception difficult without radar and integrated air defence systems. Add the influence of Douhet's 'Bomber will always get through' mindset and it's hard to see an early driver for rockets.
It's worth remembering the late-1930s obsession with air defence in certain countries, especially Great Britain. The development of Radar was primarily driven by efforts to solve the perceived existential threat of bomber attack on cities. The development of the 'Z' batteries- Britain's AA rockets- was also driven by the desire to develop a wonder weapon to reverse the perceived advantages for the attacker in the air. Modern investments in anti-missile systems arguably fall under the same impetus, so clearly countries are sometimes motivated to spend money attempting to develop counters to apparently unstoppable threats.

Rockets would most obviously fit on the heavy fighters then en vogue- typified by aircraft like the Me 110 and the Potez 630. The concept called for a twin engine, two or three crew aircraft, heavier than a fighter but lighter than a bomber, extremely fast: capable of filling a variety of tactical bombing, reconnaissance, bomber escort, and bomber interceptor duties while using its high speed to simply ignore more maneuverable single-engine fighters (not all air forces requested all missions, but the general desire for a multi-role aircraft partway between a bomber and a fighter was common to several different Air Forces). One problem designers faced was the need for flexible armament- recon roles would require as much as possible to be stripped off and replaced by cameras, ground attack required heavy bombloads, and interception required weight-of-fire capable of bringing down heavily armoured targets (by aerial standards). That's where I see rockets fitting in. If somebody designs zero-length launch rails prewar, then you could easily build air-to-ground and air-to-air variants capable of launching from the same hardpoint, and the effect of zero-length launch rails on performance is negligible enough that stripping the aircraft for a recon role would only require removing the rockets, not the launching hardware.

Even so, I wouldn't expect a success from the plane and rockets developed prewar in their doctrinal roles- merely an interesting weapon system well-placed for further development.
 
When the Bristol Beaufighter is introduced into service in addition to the 6 x .303 Brownings and 4 x 20mm HS 404 cannon they are also armed with a single 37mm C.O.W. gun mounted in the fuselage to engage aircraft above and ahead of the Beaufighter. This arrangement had been experimented with in the early 30's and was trialled in early 1940 in four Blenheim IVF night fighters.



View attachment 737901
Gosh, I was hoping to be the first to reference the C.O.W. gun, but I can at any rate add that this Westland was just one of two responses, the other being a much weirder airframe by Vickers:

Quoting the above link,
...it has been suggested that the Type 161 may have been the first aircraft to have had inflight adjustable elevator trims.[4] In September 1931 it went to RAF Martlesham Heath for trials, where no serious problems emerged and pilot's reports were positive. The gun-firing tests went well, with no detriment to airframe or performance. Despite that, neither the Type 161 or its competitor the Westland C.O.W. Gun Fighter were ordered and no more was heard of the aerial COW gun.

Too bad, as the Germans had considerable success with an upward firing gun of their own, the "Schräge Musik" family. So on one hand I can see that the 1931 OTL date of these two competing models is out of OP frame, but on the other the actual application of the concept by the Luftwaffe certainly would justify an ATL revisiting of the idea by the RAF in mid- to late 30s.

I first heard of upward firing guns in a book about Freeman Dyson, who worked in Operational Research during the war, and inferred from data on air raids the Germans must be using these sorts of AA weapons, and was basically told to shut up by Bomber Command because it would be demoralizing to tell the raiders what they were up against. I suppose Dyson might have known about the Coventry Ordinance project. Of course it could also be that Schräge Musik had some important differences from the COW concept in detail--IIRC the COW Gun fired a very heavy but remarkably slow shell, hence the need to angle it upward a great deal to give it any range at all, perhaps Schräge Musik involved more conventionally fast smaller shells?

Honestly the thing that interested me most was not the gun but the Vickers airplane, as it is an example of a shaft-driven pusher prop installation that seems interesting to me, particularly the wacky business of the prop working at the mid-length of the fuselage, meaning the tail boom is a cantilevered thing running through the prop hub! I only just found out about the Westland competitor today, as a cross reference in the article on the Vickers plane, and read it just before reading Peg Leg Pom's post.

Anyway it deserves a mention in the context of this thread focus--the COW Gun I mean and the general concept of upward firing guns installed on interceptors.
 
Since the earliest electric drives existed in the late 19th Century for urban & interurban railways the potential was there.
And the French Saint-Chamond of 1917 with gas electric drive, adopted from Railcars built by Crochat. the 90HP engine drove a generator, that powered an electric motor for each track unit.
Since it was very underpowered at 25 tons, the Gas-electric system got a bad rap
 
What about the marrying up of dispensers to shaped charge submunifions for the anti tank role on a much wider scale than was employed in the OTL, I know the raf and ussac had some canvas walled dispensers in late 44 45 but am thinking have them much earlier in the war say 41 or 42 , it might improve the performance of the desert airforce against armour for example. it could also be adapted to carry other payloads for example air dropped mines am thinking in the night intruder role over luftwaffe airfields as well. It would bring the advantage of requiring a less accurate delivery from aircrew and it would cover a greater area compared to a traditional fragmentation bomb. Would they also be a niche use against something like the EBoats that costal command and the FAA battled throughout the war?

In essence have a rockeye or bl755 type weapon wode spread operational use in 41 or 42

Iirc correctly most of the dispensers used for most of the war was as containers for incinderaries used by bomber command on its night raids rather than on tactical aircraft as I propose certainly until late in the war.
 
Gosh, I was hoping to be the first to reference the C.O.W. gun, but I can at any rate add that this Westland was just one of two responses, the other being a much weirder airframe by Vickers:

Quoting the above link,


Too bad, as the Germans had considerable success with an upward firing gun of their own, the "Schräge Musik" family. So on one hand I can see that the 1931 OTL date of these two competing models is out of OP frame, but on the other the actual application of the concept by the Luftwaffe certainly would justify an ATL revisiting of the idea by the RAF in mid- to late 30s.

I first heard of upward firing guns in a book about Freeman Dyson, who worked in Operational Research during the war, and inferred from data on air raids the Germans must be using these sorts of AA weapons, and was basically told to shut up by Bomber Command because it would be demoralizing to tell the raiders what they were up against. I suppose Dyson might have known about the Coventry Ordinance project. Of course it could also be that Schräge Musik had some important differences from the COW concept in detail--IIRC the COW Gun fired a very heavy but remarkably slow shell, hence the need to angle it upward a great deal to give it any range at all, perhaps Schräge Musik involved more conventionally fast smaller shells?

Honestly the thing that interested me most was not the gun but the Vickers airplane, as it is an example of a shaft-driven pusher prop installation that seems interesting to me, particularly the wacky business of the prop working at the mid-length of the fuselage, meaning the tail boom is a cantilevered thing running through the prop hub! I only just found out about the Westland competitor today, as a cross reference in the article on the Vickers plane, and read it just before reading Peg Leg Pom's post.

Anyway it deserves a mention in the context of this thread focus--the COW Gun I mean and the general concept of upward firing guns installed on interceptors.
I claim the COW gun prize for post 18!
Though I'll admit I was just thinking about how to do something useful with a Defiant and hadn't realised there was anything in OTL.
 
Germany/Luftwaffe adopts the Italian 12.7mm in 1935 instead of the FF cannon from Oerlikon. Being belt-fed, it gives a much better firing time than what was available with the 60 rd drum-fed cannons like the MG FF was, and it is also better ballistically similar to the MG 17 and future MG 151/20. Four on Bf 109E, six on Bf 110 and Fw 187.

UK and USA buys an Oerlikon cannon design ; no wait for the Hispano. RAF has workable cannon armament in service for the BoB, Americans don't suffer the 'light primer strike' problems since the Oerlikon cannons do not depend on round being chambered to be fired. The FF cannon is very light, with low MV; the S is biggest and heaviest (similar to the Hispano in that regard), with best MV but with lovest RoF. The FFL is probably at the sweet spot.
 
Solving/avoiding the German 30+- mm air-to-air problem, until the 30mm revolver cannon can be had:
- MK 108 with a short & light shell (250-270g) so the MV is also useful against small and/or a bit more distant targets
- MK 103 with down-loaded ammo, so the cannon can be used in pairs on a Fw 190 without the vicious recoil. Perhaps ~80 g instead of 110g (for comparison, the lowly MK 108 used just 30 g of propellant), for a MV of 700+ m/s. Yes, modify the recoil spring(s) accordingly so the gun can actually cycle. Designing the MK 103 from the get-go as a motor-cannon need to be done, not to wait until 1944/45.
- MK 108/25 - fires the 25mm ammo, predominantly the 200g M-shell at 700 m/s (steal the bits & bolts from France to expedite the design job)
- 'MK-105' - bigger & heavier MK 108 spin-off, 330g M-shell at 700 m/s

Granted, some of these suggestions are easier to make than another ones, especially in the time of war.
 
As a stopgap in 1940 while the HS 404 is adapted for belt feed Hawker Hurricanes have two of the .303 Brownings in each wing replaced with a single 15mm Besa with a shortened barrel?

Heavy, bulky, slow firing, inaccurate and you'd need to develop a proper belt system. Also no incendiary ammunition.
.50 Browning is vastly better.

The 15mm Besa was probably silently asking to be over-bored to 20mm, much like it happened to the MG 151/15? :)
Between the .303 and the future 20mm, British can adopt the Vickers 'Class B' HMG, a pretty handy weapon at 24 kg, and firing at 700 m/s; belt-fed.
A HMG will also be far better as a defensive weapon for aircraft than a LMG, while not being too ... clumsy as a full-power 20mm in that role.
 
My big ask for the period would not be a new weapon, but for the USAAF to get their guided bombs like AZON and RAZON into service earlier and in numbers. The book on the subject is Near Miss, and it argues that the USAAF had too many projects puttering away in small scale testing with no General in overall charge who could push forward promising developments into actual weapons. Ideally, there would have been some clarity in the US program, and the steerable bombs, the weapons that were actually retained post war, would get into service by the beginning of 1944. I was thinking that they would by ideal for bridge busting in France and Italy, being a good solution for limiting collateral damage.
Your posting reminds me of a thread I created a few years ago.

"Inspired by recent comments in the Keynes' cruisers story I offer this speculation about how to build a precision guided Tallboy-like all weather bomb using late WW2 technology.

https://en.wikipedia.org/wiki/ASM-A-1_Tarzon

This wikipedia article describes one version of the radio controlled bombs deployed by the Allies late in the war. A key point is they were steered unto their target by the operator visually tracking the bomb which had a flare attached to its tail so as to improve its visibility to the operator. This required daylight operations only in clear or nearly clear weather conditions.

Could these and similar heavy weight bombs have been dropped using radar guidance? Did the USAAF H2X radar of 1945 have the resolution to identify large structures like power stations, industrial complexes or dams. Or ships at sea?

If so then instead of the bomb being fitted with flares for visual tracking have instead a very low power radio transmitter on the same frequency as the H2X radar be fitted to the bomb. Very low power so as to not jam the radar return but instead it would show as a small dot on the radar scope. Also a low power SHF (less than 1 watt) transmitter would not require the cavity magnetron and a large power supply.

The radar operator would find and identify the target. The bomb would be dropped and the bombardier using the same or possibly a repeater scope would steer the dot onto the radar target using the same RAZON system. This system allows high altitude precision bombing at night and/or in overcast conditions. Opening up many important targets to precision bombing with Tallboys and Grand slam earthquake bombs while reducing the risk to the flight crews since they would bomb at night from at least 30,000 feet.

Ships at sea would also produce a strong radar return. This system could be used for attacking even the largest enemy warship. Even the Yamato would not have survived Tallboy or Grand slam hits. It wouldn't take many. And if it had been attacked at night from 30,000 feet they might not have even know they were being attacked meaning no evasive maneuvering. However if this system works even a maneuvering ship would still be hit.

If something like this had been worked up in 1942 than Barnes Wallis' designs would have shortened the war." Old posting by me. https://www.alternatehistory.com/fo...arthquake-bombs-and-tarzon-with-radar.460873/

Whether this system could be easily jammed or not and how effective and accurate it would've been are open questions. But even a flawed system would have a been a huge improvement over the wanton destruction that couldn't be avoided using the area bombing method. And if it did work reasonably well? Destroying every electricity generating station in the Third Reich in a couple of months or so for example.
 
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Near Fantasy desire?

1.1" in a three barrel Gatling in the nose for a Grumman F5F
In Metric rather than Freedom Units, that cartridge is designated as 28x199mm with 823m/s velocity, with a 416 gram HE-T projectile with 17 grams of Comp D burster. 36000psi working pressure
Well, if we are discussing our favourite hobby horses. What's better? A 28MM Gatling or a 30MM "mine shell" cannon?


"
1616527014417.png

https://en.wikipedia.org/wiki/Survivorship_bias from the Wikipedia article.

Here is the well known image used to illustrate survivor bias as describe by Abraham Wald. Planes hit in the marked spots would often still be able to return home. There is no data recorded for the unmarked spots because the planes hit in those areas didn't return so hits in those places were not recorded.

But it's not survivor bias I'm discussing here but how ineffective WW2 era fighter armament was. This graphic illustrates how aircraft could absorb hits, frequently multiple hits, in various locations and still be able to return home. It's was difficult to achieve precise accurate firing in the split second afforded in WW2 aerial combat. For the Allies, the British using a mix of .303 MMG and 20 mm cannon and the Americans using .50 caliber HMGs showed the difficulties in achieving reliable kills in a single pass. It was very difficult for most pilots to achieve accurate firing on the enemy airplane's kill spot in a split-second. This meant enemy aircraft often surviving with a few holes drilled in non essential places. Hence we read about after action reports that would be listing confirmed, probable and damaged with many more E/A in the latter two categories.

This Youtube video I've linked to here shows the RAF test firing the German MK 108 cannon on aircraft targets. The level of damage produced by single hits is significant.


What's most compelling about this video is it describes catastrophic damaged produced by single hits. Even in areas on the plane that would have been able to absorb hits from smaller caliber, less explosive munitions. This is why I'm suggesting that a weapon of this type would have been the best possible weapon for Allied fighter planes using the existing 1940s technology. Because one hit would very likely destroy an enemy fighter plane. Two hits would be a dead certainty.

During a typical WW2 aerial combat over Germany a Mustang pilot squeezes off a quick burst at a FW 190. The U.S. pilot doesn't lead the Focke-Wulf adequately during the split-second he has to aim and shoot. Consequently a couple of .50 API rounds drill through the 190's vertical stabilizer doing no serious damage. If the Mustang was equipped with two wing mounted 30 mm cannons firing shells that are carrying 85 grams/3 ounces of RDX then just one hit would blow off the 190s' vertical stabilizer taking the rudder with it. An exaggeration? Please refer to the RAF's video posted here showing the testing of these shells.

Those 30 mm shells had an explosive power greater then a WW2 U.S hand grenade. Where can a hand grenade be detonated on a fighter plane that wouldn't destroy it? A hit on the rear fuselage would blow off the tail. On the inner wing it would open a hole in the fuel tank the size of a dinner plate and ignite the fuel. The cockpit area would kill the pilot. I believe the use of munitions with that level of explosive power was approaching as close to one shoot, one hit, one kill for Allied fighters as was possible without the post war development of guided air to air missiles.

Also, a clarification. I'm not advocating the MK 108 cannon the Germans developed. That was specifically designed to attack the large, unmaneuvering bomber formations of the Allied, mainly American, daytime bomber offensive. Hence the low muzzle velocity of the MK 108. Not very useful for attacking fighters.
It's the high explosive 30 mm shell that is the hidden gem here.

Could the Allies have developed a similar weapon? A 30 mm round with a similar explosive power as the German 30mm/99mm "mineshell"? But designed with a larger case to increase the muzzle velocity? What would be ideal is a gun that can fire about 10 rounds a second with a muzzle velocity nearing 900ms/3000fts. Firing a 30mm round carrying 85grams/3 ounces of RDX. And made small enough to fit in the wings of Spitfires and Mustangs. Thunderbolts and in the nose of Lightnings. Even if the firing time is reduced to 10 seconds or so due to the size of the rounds in the available magazine space the effectiveness of each fighter well makes up for that.

If somebody had thought of it could it have been feasibly done with mid-war Allied technology?" Old posting by me. https://www.alternatehistory.com/fo...-for-use-by-ww2-allied-fighter-planes.507208/
 
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