Effectiveness of Bomber Defensive Armament by Type and Location

[Thumpalumpacus]

Indeed, "learning curve" is the key phrase. But as capabilities opened up, so too did thinking.

Sometimes doctrine informs the design process. Sometimes a revolutionary design changes doctrine. Sometimes there's a cross-pollination between the two mindsets.

I think the Mossie's capabilities were so advanced that it made people sit down and ask, "what can we do with this?"

 

[wuzak]

The addition of fast, precise planes added pathfinding to the doctrine of BC, did it not? How much pathfinding did BC practice before the Mosquito became available? That was exactly why I thought it changed doctrine a bit.

If I'm missing something here I'm all ears. But I think the Mossies did sterling work (if you'll pardon the pun) putting the heavies in on target, a capability BC didn't really have in 40-41. Am I missing something?

Pathfinding existed in Bomber Command before the Msoquito was adopted for the role in 1943. Even then the pathfinding force was equipped with several types, including Lancaster and Stirling.

The big advantage the Mosquito gave pathfinding for BC was altitude. The Mosquito flying 10,000+ feet higher than the other types increased the effective range of the electronic aids.

The pathfinding force was set up in 1942 under Don Bennett.

As the story goes, Bennett went to a meeting to request Mosquitoes for use as pathfinders, only to be told that the Mosquito was unsuitable for flying at night. Which surprised Bennett, since he had flown to the meeting in a Mosquito - at night.

 

[wuzak]

Oh, I forgot to mention, the turret-armed Mosquito bomber (not the night fighter, which was a standard Mosquito) was to be powered by Griffons. C.C. Walker, de Havilland's Chief Engineer advised that fitted with a Nash and Thomson FN.4A four-gun rear turret, a 1,000lb bomb load and a crew of three, the Griffon engined aeroplane could reach speeds of 390 to 400 mph at 20,000 ft.

There was also a proposal to fit the Mosquito with a fixed rearward firing "scare" gun, but that also came to nought.

 

[wuzak]

The upper position for the turret on the Mosquito was for a night fighter, not defensive armament for a bomber, as Wuzak stated. The Air Ministry did request a turret for the bomber Mosquito, but it was a tail turret and the only trials conducted were paper exercises, which thankfully never amounted to anything more than the production of figures. The prototype was fitted with a dummy for aerodynamic purposes to aid in the development of a turret fighter for a night fighter specification and two prototypes were built and fitted with gun turrets, but the Bristol turret fitted to the aircraft was insufficiently capable of operating at the speeds the Mosquito flew at; it's hydraulic system couldn't produce enough pressure to rotate the turret in flight.

I believe the position of the turret on the turret-fighter prototype would have cut into the bomb bay, reducing its bomb carrying capacity (as would, obviously, the weight of the turret).

I am not sure if the turret-fighter prototype was also to be fitted with the 4 20mm cannon, since they would also occupy the same space at the forward end of the bomb bay.

 

[SplitRz]

The problem with all bombers is they need to run straight and level (pretty much) to hit the target leaving them vulnerable to AA & fighter attack. these were where the greatest losses occurred. The Fighter/Bomber version had one of the best defensive armament set-ups with the 4 x .303 Browning and 4 x 20mm Hispano MG's

Minor clarification, but those were OFFENSIVE *not* defensive guns. Any Mosquito forced into a turning fight with a Bf109 or F190 after being bounced is unlikely to get a shot in. FBs used that armament primarily on ground targets and larger aircraft if they strayed into their sights. The FBs protection was in speed (though the opposition usually had height advantage which negated that), low level approach and getting out quick.

 

[SplitRz]

While reading up on the Tupolev Tu-2 I came across a post Shortround made in 2018 saying that the British estimated that a powered mount was three times more effective then an unpowered mount. This got me curious about the relative effectiveness of the various weapons mounts employed on WWII bombers. Not only the effectiveness of the different types of guns themselves, but also of the types of mountings used and the locations of those mountings (chin, tail, dorsal, ventral, waist, etc).

My interest in this subject is partly out of personal curiosity though one of the people working on a strategy game mod I am doing research for has expressed interest in studies on the topic if any are available. I also figured there might be other people on this board with an interest in the general topic.

Its an interesting question, for sure.

I guess the brutal Darwinism of war and the consequent evolution of bomber armament tells its own story. The lesson seems to have clearly been that no amount of armament would ultimately make a bomber an equal to a contemporary attacking fighter in terms of loss rate. And given that a fighter is always going to be cheaper in terms of crew, manufacture and material cost, even a 'one for one' would be unsustainable for the attacking force - especially if its a heavy bomber (all other considerations being equal).

History seems to have shown that the performance penalty of carrying turrets / crew manned guns was something of a balance - and as others pointed out, a lighter aircraft unburdened by their weight and drag can theoretically carry more bombs, likely higher, faster and further. At some point, the advantages of those aspects and reduction in likelihood of interception or having to make repeated raids onto the same target to ensure its destruction, will overtake the advantage/liklihood of the bomber being able to dissuade/disable/shoot down an interceptor. However, during WW2, with the exception of the Mosquito - and perhaps the B29 at the end of the war, the general trend was to try and add more defensive positions and heavier calibre defensive guns (even if the RAF were late to that aspect!)

There are lots of variables - the relative performance difference between bomber and interceptor, mission environment, whether its by day or night etc etc... But given that both the USA and USSR continued to design and field aircraft with tail turrets post war, I suspect the clear implication there is that the tail turret would qualify as the most effective and worthwhile position from their perspective at least. An intercepting aircraft is by necessity most likely to be coming from the rear, its the quarter which pilots and other crew members in the cockpit can least see, and it also affords the gunner with one of the widest fields of fire. It may also (and shooters here can correct me), provide the gunner with the least complex firing solution, making the chance of hitting an attacking aircraft higher. Aerodynamically, it may also be less compromising I'd guess than other turret positions.

Some aircraft without the ability to outrun or outmanoeuvre an interceptor were pretty much reliant on their gunners. But again, there' a difference in practicality and approach between a box formation of bombers using massed ranks of guns with interlocking arcs of mutual covering fire like the B17s and B24s - or something like a Lancaster operating in a stream in darkness. There's also scenarios for aircraft like Il2s, operating relatively slowly and as a 'gaggle' rather than a strict formation.

Anyway, I'm now asking myself nearly as many questions

You might find the following of interest: Wallace McIntosh - Wikipedia

 

[wuzak]

An intercepting aircraft is by necessity most likely to be coming from the rear, its the quarter which pilots and other crew members in the cockpit can least see, and it also affords the gunner with one of the widest fields of fire. It may also (and shooters here can correct me), provide the gunner with the least complex firing solution, making the chance of hitting an attacking aircraft higher. Aerodynamically, it may also be less compromising I'd guess than other turret positions.

Well, that depends.

Defending fighters will be climbing to altitude ahead of the incoming bombers, so the logical place for the fighters is to the front.

When the bombers are fast it makes it difficult for the fighters to swing around to attack the rear.

When the bombers are slow the fighters can choose which angle to attack from.

 

[nuuumannn]

I believe the position of the turret on the turret-fighter prototype would have cut into the bomb bay, reducing its bomb carrying capacity (as would, obviously, the weight of the turret).

I am not sure if the turret-fighter prototype was also to be fitted with the 4 20mm cannon, since they would also occupy the same space at the forward end of the bomb bay.

It would have, definitely. The Mosquito had a one-piece wing, the lower surface of which was the roof of the bomb bay, so a hole was cut in the wing to fit the turret. Access was from the exterior only. It was not fitted with the four 20mm cannon, only the turret and the nose-mounted mgs.

 

[Rjay]

Well, that depends.

Defending fighters will be climbing to altitude ahead of the incoming bombers, so the logical place for the fighters is to the front.

When the bombers are fast it makes it difficult for the fighters to swing around to attack the rear.

When the bombers are slow the fighters can choose which angle to attack from.

 

[Rjay]

My dad, a WAG on the Halifax bomber, told me the Germans quickly learned the vulnerability of the Halifaxes. They would come up from underneath, where the Hali was vulnerable. Which worked well until many of them pulled the radar out of the dome, cut a slot in it and put a man with a 50 cal waiting there for them. He never explained who was the lucky guy who sat there. Surprised many a fighter at first…

 

[33k in the air]

My dad, a WAG on the Halifax bomber, told me the Germans quickly learned the vulnerability of the Halifaxes. They would come up from underneath, where the Hali was vulnerable. Which worked well until many of them pulled the radar out of the dome, cut a slot in it and put a man with a 50 cal waiting there for them. He never explained who was the lucky guy who sat there. Surprised many a fighter at first…

Yes, the 'mid-under gunner' position as it was known, the 8th crewman. A number of squadrons in 4 and 6 Groups added this position in 1944. Quoting from The Crucible of War:

Four Canadian crews who returned safely had been attacked by fighters. In three cases Monica provided little or no warning of the fighter's approach, illustrating is limitations, and only the vigilance of rear and mid-upper gunners enable their pilots to take evasive manoeuvres in time. In the other, Monica did provide ample warning, but it was the mid-under gunner who first saw the fighter 'silhouetted against cloud, below, passing from Starboard to Port.'

This 'mid-under' position was a recent modification adopted by No 419 and other non-H2S squadrons to address the threat of fighters approaching from below.

 

[Milosh]

My dad, a WAG on the Halifax bomber, told me the Germans quickly learned the vulnerability of the Halifaxes. They would come up from underneath, where the Hali was vulnerable. Which worked well until many of them pulled the radar out of the dome, cut a slot in it and put a man with a 50 cal waiting there for them. He never explained who was the lucky guy who sat there. Surprised many a fighter at first…

Hallies and Lancs did have lower gun positions. They were removed because they were pretty useless, tho helped with morale.

https://ww2aircraft.net/forum/media/lancaster-fn-64-ventral-turret.30699/full

 

[Milosh]

After the Luftwaffe became aware of Monica from a crashed bomber, German scientists developed a passive radar receiver, named Flensburg (FuG 227). From early 1944, FuG 227 was used by nightfighter crews to home in on Allied bombers using Monica.

 

[Rjay]

Hallies and Lancs did have lower gun positions. They were removed because they were pretty useless, tho helped with morale.

https://ww2aircraft.net/forum/media/lancaster-fn-64-ventral-turret.30699/full

I believe the Lanc maintained a belly gun (for the most part) and leaving no protection on the underside is a fatal flaw for a bomber. The retrofitted belly gun wasn't just for moral I assure you.

 

[Milosh]

Any good tail gunner should be able to spot any e/a coming up from behind.

 

[pbehn]

Any good tail gunner should be able to spot any e/a coming up from behind.

Frequently they didnt come from behind, they came from below and to the side.

 

[33k in the air]

After the Luftwaffe became aware of Monica from a crashed bomber, German scientists developed a passive radar receiver, named Flensburg (FuG 227). From early 1944, FuG 227 was used by nightfighter crews to home in on Allied bombers using Monica.

There was also the Preston Green mid-under turret, which had a single .50-cal machine gun. This was fitted to some Halifax bombers, but as H2S became more widely available, these turrets were replaced with the H2S radar dome.

There were also jury-rigged mid-under gun positions in some squadrons.

 

[Greyman]

Hallies and Lancs did have lower gun positions. They were removed because they were pretty useless, tho helped with morale.

The turrets worked well enough -- in daylight (see RAF Mitchell squadrons).

Maintaining a search though a periscope, for hours on end, at night, was deemed difficult enough to not warrant inclusion.

The more ad-hoc .5-inch position Rjay's father describes is something different.

 

[Milosh]

You think the rear gunner only looked straight behind? Dad was a rear gunner and they were instructed to do sweep searches.

Frequently they didnt come from behind, they came from below and to the side.

 

[pbehn]

You think the rear gunner only looked straight behind? Dad was a rear gunner and they were instructed to do sweep searches.

I know but even with a sweep search you dont see what is underneath.