The rear turret
 

Good job this isn't a thread on JetBlast!

I was watching an excellent walk-through yt video of a Lancaster in the RAAF museum I think [1] and they showed the ammunition bins placed near the cg of the aircraft (I hadn't thought about that requirement, but yes it makes sense) and also the raceways to take the ammunition from there to the rear turret. My question is: How did they feed the ammunition into the rear turret?

If it was a fixed position that would be a fairly simple task, but given that it could rotate left and right, it must have required something to stop the belts being stretched or compressed and possibly jaming. Maybe they went down (or up) and came into the turret through the central pivot point, but that seems pretty awkward too.

Also there was a set of doors in the aft fuselage (not the turret doors) that could be closed. Was that a fire door? Seems like it was extra weight, so must have been important

Finally (and this is perhaps a silly question) if you look at the greenhouse, it extends way past the cockpit area, in fact over the Nav and radio operator positions I think. It looks like the back part of the greenhouse is a big shelf, but one that if you put anything on it, would be very difficult to retrieve. It just seems like an unusual design and maybe a smaller greenhouse (like the Stirling) or blanking off that area with a wall or a net. Stuff must have got stuck up there. Why was it built that way?


[1] If you're interested:

that's a LOT of detail - thanks for that. I think I see how it works now

I also watched the Canopy one and while it didn't say much about that big shelf, I see it was used to contain the DF antenna, so that would have helped reduce drag

The doors in the aft fuselage were "wooden draughtproof doors" apparently

If we're raising questions about the RAF's heavy bomber fleet, was the mid upper turret really of any use?
Either have the H2S dome right under the bomb aimer position and a ventral turret (apparently that was the intended use and even built into the fuselage) or could it have been mounted in the mid upper position?
And as for the nose turret - why? Won't you have a 200+mph wind/rain/sleet/snow/hail/birds into your face it must also have had some effect on the bullets being fired forward....
If they were to have any real use, the guns needed to outrange the night fighters, or have some real stopping power for a one bullet "kill".
Seems we just gave the illusion of self defence at the expense of 3 extra "crew" that just sat in their turrets trying to penetrate the darkness.

That to me is the epitome of braveness, flying night after night with pop guns against cannons.....

"Seems we just gave the illusion of self defence at the expense of 3 extra "crew" that just sat in their turrets trying to penetrate the darkness."

because bombers always had defensive weapons ... in WW1.

No-one was willing to change things even though it was obvious that at night and +200mph the chances of a successful shoot down were near zero

Fixed guns in the nose and an observer at the back would have made a lot more sense until radar controlled guns came in - and then you'd want something serious not a set of 0.303's

I remember reading somewhere that an Air Gunner in 617 Sqdn insisted on loading his own ammunition. His hit rate was significantly higher than the norm. It seemed that they were not even willing to change things after that.

"His hit rate was significantly higher than the norm. It seemed that they were not even willing to change things after that."

Was that based on a verifiable test or a report? the problem was , like AA gunners, any enemy aircraft that was hit was claimed by everyone in sight

The RCAF had belly turrets on their bombers but I never saw any figures to prove or disprove that they lost less aircraft because of it - the attack from underneath being very common and very lethal

I've read about the gunner who loaded 100% incendiary rounds, even loading his own belts to save the armourers the trouble. Some Canadian squadrons used 100% tracer, the extra barrel wear being considered worthwhile as the hail of fire from an alert gunner was enough to make most fighters break off. Especially when they were sneaking up beneath the bomber to use their upward-firing cannon, which caused most bomber casualties after their introduction in 1943. ~Again the Canadians of 5 Group recognised the danger but there was no ventral turret, just a 50 calibre machine gun on flexy mounting like the American side guns.

Can't remember the reference, but following statistical research it was proposed to delete the mid-upper turret which was little used and gain an extra 50 mph which would make life much more difficult for overtaking fighters. This research also led to the introduction of the bomber stream in which defences were swamped by hundreds of aircraft bombing in only 20/30 minutes. The furious crews refused to give up their mid-uppers and maybe they were right, for the one ton weight gain would swiftly have been negated by the order to carry an extra ton of bombs instead.

However, many a German airman could testify as to the effectiveness of the rear gunner, especially if he was trying to creep underneath his target. Even quadruple .303s were devastating at close range from above when all he had was 8mm Perspex above his head, and upper surfaces of fuel tanks had nothing to protect them. Ultimate version was the Village Inn gun-laying radar, google it for several accounts of how well it worked -- indeed so well that it wasn't used because so many friendly aircraft were close by in the bomber stream.

I read a book about the US 8th AF/B-17 raids over Europe.
At least according to that source, the planners concluded that it took the fire from 10 machine guns (50 cal on a B-17) to effectively 'discourage' attacking German fighters. Hence the focus on tight formation flying, where multiple B-17s could bring guns to bear on an attacking fighter and (hopefully) discourage the attacker before he got close enough to be effective.
I think the typical load was one tracer ever 5 rounds - so having all tracers could easily fool an attacker into thinking 5 times that many rounds were inbound.

To add some ‘meat’ to some of the comments above I can add this:

I believe that it was Freeman Dyson that proposed removing all turrets on Lancasters in particular; as well as reducing the crew complement by 2, it would have added circa 50mph to the speed, putting it outside of a stern chase envelope of a Bf110 or Do217, made a JU88 work VERY hard for an intercept, but still be quarry for a He 219. However, the idea was pooh-poohed at sqn level where more worldly-wise heads reasoned that the extra performance would have been used to increase range or, more likely, increase bombload thus obviating any performance gain!

The gunner that may be being alluded to is likely to be FS Tom McLean DFM, who was an experienced and thoroughly ‘professional’ gunner. On being posted to 617 – already with 5 confirmed kills to his credit - he ‘arranged’ (by doing it for himself) for his guns to be loaded with 45% tracer and 55% armour-piercing ammunition; the first for scare effect, the latter for effectiveness. On the night of 15/16 Mar 44, McLean’s Lancaster was engaged by 3 x Bf 110s and 1 x Bf 109. McLean destroyed the 3 x Bf 110s and the Bf 109 was possibly damaged or destroyed by the Mid-upper Gunner as well. This success was probably due to this crew undertaking extraordinary self-imposed additional training in fighter affiliation sorties and working out a highly disciplined crew response to the potential of being attacked by night fighters.

At most night engagement ranges (<400m) the 4 x .303s were effective enough – just; the gunner just had to SEE the threat first. There is no doubt however that 0.5s should have been introduced much earlier than they were; the most effective Lancaster version should have been the Mk VII or X with its 2 x 0.5s in the forward mounted Martin mid-upper position and the Rose-Rice tail turret.

The problem is that these kills were completely uncheckable at the time - at night, under fire, in an aircraft that was all over the shop.

even in daylight claims by both sides were significantly overstated

"After the Second Raid on Schweinfurt, USAAF gunners aboard the B-17 bombers claimed to have shot down 138 German fighters. German records show that 38 were lost and 20 were damaged. German fighter pilots claimed they shot down 121 bombers and 1 fighter. USAAF records show that 60 bombers and 1 fighter were lost, 17 bombers were scrapped, and 121 bombers were damaged.[size=8333px]"[/size]

I'm sure the crews were correct tho'

Increased performance would have been traded for more fuel and bombs - of course once you dropped the bombs there'd still have been a notable increase in performance on the way home

An old friend of mine (WO Walt R******t) was a WOp on 12(B) Sqn Lancs from Dec 44 - Apr 45. He told me that their Mid Upper Gunner made his own 'mix' of ball to tracer. He reckoned the normal mix was '4BIT' = '4xBall, 1 x Tracer', but he said that his MUG's preference was '1BIT' = 1xBall, 1xTracer, and said that when the gunner opened up it was like Blackpool illuminations. But what Walt did say was that the combination of this light show, combined with the gunner's accuracy kept them safe form the attentions of the Luftwaffe.

However, the downside was that the same MUG shot down his own Lanc on 27 Feb 45!!! They were airborne on an air-to-air firing duty, and when the Mid-Upper Gunner was firing, the guns 'stuck' on 'fire'. The gunner jumped down to break the links, but, not only did the guns continue to fire, but the turret also continued to rotate, and, to add insult to injury, the interrupter gear failed to work. So the 1BIT raked the port wing from leading edge to trailing edge causing the wing to catch fire. The pilot ordered the crew to bail out, but he managed to land safely!!!

Sounds unlikely, and a bit of a 'line shoot', but, after his death, I was left Walt's medals, his Caterpillar Club badge, his Caterpillar Club 'certificate, and his Log Book. And the entry for 27 Feb 45 simply states (and no 'I'm a [bloody] Celebrity...' style histrionics here):

Date - 27/2/45; A/C - "J"; Pilot - F/O Large; Crew Duty - W/Op; Duty - Air to Air Firing (Port Mainplane on Fire - Bailed Out). Skipper Landed A/C; Hrs (Day) - 0:50

This seems like an appropriate thread to post a picture that I took today. I was visiting MOTAT in Auckland for the first time in 12 years. Lots of changes. All the aircraft are undercover now which is great news.

This is the first time I had seen a Rose turret with twin 0.50 cal machine guns on a Lancaster:

https://cimg8.ibsrv.net/gimg/pprune....e5113ad060.jpg


https://www.motat.nz/exhibitions/aviation-hall/

Hi I-42. That's a FN82 rear turret - the 'Official' Air Ministry response to the 0.5 Requirement. It entered service, I believe, in June '45! Which tells you all you need to know about the AM's allocation of priorities..... and underlines Harris' frustration with the staff there.

I think you mean the Canadians of 6 Group.
The idea of removing the turrets came from Freeman Dyson, who joined the Operational Research Section of Bomber Command on July 25, 1943.
The bomber stream was first used on Operation Millennium, the first thousand bomber raid on Cologne, 30/31 May 1942. This was proposed by Dr RV Jones.
Post war research suggested that Dyson's theory may have been wrong and an increase of 15-20mph was only achievable.
I don't think it was the crews that were against giving up their turrets, as the recommendation by Dyson was never accepted by Harris and thus never permeated down the chain of command.

Interesting info. Sorry I can't remember the detail as I was only a youngster at RAF Binbrook in 1948-51 and worshipped my father's friend Bob Nash, RCAF, who had flown two Lancaster tours and patiently drilled me each Sunday in the fully equipped cockpit of the old Lancaster used for dinghy/crash practice. He remarked one day that they often used emergency power for takeoffs, such were the bomb-fuel loads. (The Lancaster startup/taxi/takeoff drill was quite a showstopper at our kids' parties and other parents gave my mother a sympathetic look, today I would probably be sent for counselling.)

Bob remarked one day that some of his countrymen had a belly gun in place of the H2S cupola, though he preferred the navaid. Of course I couldn't understand the significance of either. With hindsight we know the Luftwaffe had an H2S homing device within a few months of its introduction so Allied crews were advised to use it for a few seconds only.

Re the 50 calibre turret above: I remember seeing these still mounted in Lincolns of 12 Sqn over a weekend following night flying exercises. The idea of mounted and unguarded guns would horrify us today. Most intriguing was the torch bulb mounted in the blast muzzle, with its lead down the inside of the barrel. Presumably it was linked to the trigger and the fighter would consider himself 'shot down' on seeing the bulb illuminated.

[QUOTE=Geriaviator;11552226]Interesting info. Sorry I can't remember the detail as I was only a youngster at RAF Binbrook in 1948-51 and worshipped my father's friend Bob Nash, RCAF, who had flown two Lancaster tours and patiently drilled me each Sunday in the fully equipped cockpit of the old Lancaster used for dinghy/crash practice. He remarked one day that they often used emergency power for takeoffs, such were the bomb-fuel loads. (The Lancaster startup/taxi/takeoff drill was quite a showstopper at our kids' parties and other parents gave my mother a sympathetic look, today I would probably be sent for counselling.)

Bob remarked one day that some of his countrymen had a belly gun in place of the H2S cupola, though he preferred the navaid. Of course I couldn't understand the significance of either. With hindsight we know the Luftwaffe had an H2S homing device within a few months of its introduction so Allied crews were advised to use it for a few seconds only.

Pleasure sir.
On H2S, Naxos wasn't that effective in tracking aircraft and after a captured Ju88 (in summer 44) crew told of its ineffectiveness, it continued to be used.
The biggest threat was from night fighters homing in on Monica, or 'boozer' as crews called it, with 'Flensburg'.
After this discovery , Monica was removed.

Think we might have had this issue before, but does anyone else have a problem seeing any links/pics in the first couple of items in this thread?

No problems at all here.