Author Topic: il2 guns  (Read 1285 times)

Offline Tony Williams

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« Reply #15 on: November 15, 2005, 02:55:15 AM »
Quote
Originally posted by KD303
The reason being that these squadrons, on the whole, had converted to Typhoons by this time as the Hurricane had reached the end of the road. Even before that, they were using rockets rather than the 40mm option in the UK. 137 and 184 squadrons used the MK IV into 1944 but with RPs. 184 in particular had success against V1 sites on the continent. By April 44, they'd all converted.


I put the following in Flying Guns – World War 2: Development of Aircraft Guns, Ammunition and Installations 1933-45, based on papers I found in the PRO:

"The IID was not the only Hurricane to carry the 40 mm S gun. The Hurricane IV, of which over five hundred were built, was introduced in 1943 as a specialised ground attack variant. A more powerful engine enabled more armour to be fitted and it had a "universal wing", designed to take various armament options including the S gun or rocket projectiles (RPs); the changeover could be made by five men in about forty minutes. Most saw service overseas but three squadrons based in England (Nos. 137, 164 and 184) were equipped with this aircraft.

Official British reports during 1943 concerning the effectiveness of the armament options for the Hurricane IV make interesting reading. The 40 mm gun was seen as the precision weapon, usable against smaller targets such as locomotives and tanks, while the RPs were thought to be more effective against shipping. It was recommended that all Hurricane IVs should normally be issued fitted with the S gun, with conversion kits for RPs provided, and that squadrons should employ both variants, with different flights being equipped with RPs or S guns. Operations were conducted by 11 Group over France and against coastal shipping, and both guns and RPs were evidently considered satisfactory.

In June 1943 the RAF's order of preference in weapons for use against tanks was given as: 1st 40 mm S gun; 2nd 20 mm cannon with Mk III AP ammunition; 3rd RP with 25 lb AP head; 4th RP with 60 lb HE head; 5th .50" Browning HMG; 6th 9 lb AT bomb. Only the first three of these were considered to be serious anti-tank weapons. Some comment on these preferences is necessary. The 20 mm AP Mk III, as mentioned in Chapter 1, was a tungsten-cored round of considerable performance which was, in the end, not adopted. The RP with 25 lb AP head could penetrate 70-80 mm, which compensated to some extent for its lack of accuracy. The RP with 60 lb HE head was discounted against tanks as it could only penetrate 25 mm, but this assessment rather underestimated the cataclysmic effect of detonating such a large charge against a tank."


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Offline KD303

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« Reply #16 on: November 16, 2005, 05:03:54 PM »
Very interesting. My understanding is that up to, around and following D-day, the squadrons that were using the MKIV Hurricane (at least the ones I know much about, I'd have to look into others), converted to the Typhoon along with a new mission - to attack trains and other communications - 150 locomotives being destroyed every month at the height of the campaign (609 Typhoon squadron destroyed 100  locos for the loss of 2 planes). I suppose it was decided that rocket firing Typhoons were more suitable for the job, and I'd be inclined to agree. Even though the Hurricane was upgraded (well over 200 LBs of extra armour, in some cases, made it very heavy, even with the Merlin 24 or 27), it still wasn't up to the Typhoon's standard, so I suppose it had to get the chop, 40mm or no. Interestingly, number 6 Squadron kept Hurricanes until January 1947.

I haven't seen reports of Hurricane IVs using the S gun with the Mk IV from UK bases though it would seem it did happen. I'd be very interested to know more. I would have thought they would be specifically used against armoured columns on rather specialzed sorties. The fact that many of these Hurricane squadrons were indeed targetting shipping prior to converting to Typhoons maybe suggests that RPs were indeed the favoured weapon.
An aside - On the subject of 25lb solid head RPs, my Uncle flew for the Banff Strike Wing against shipping in Norway and said that they favoured the solid head for holing ships below the waterline. It was like a very heavy armour piercing bullet, he said (with his tongue only slightly in his cheek). They also rigged the rails to put rockets above and below the waterline, depending on what they were firing and the target. I have some good gun camera pictures from him in my collection which I MUST get around to posting. I also have one from a Banff Tsetse with the Molins shell clearly visible on its way to the target as well as some from the Dallachy Beaufighters (144 Squadron, mainly) carrying out rocket attacks. One sequence of pictures of a rocket attack on flak ships ( I assume they're flak ships as they were from an anti flak squadron) shows an attack from the cameras of several planes, each photograph taken within one or two seconds of each other offering perhaps an unusual view perspective on a shipping strike.
Sorry, I'm drifting off topic...

KD
« Last Edit: November 16, 2005, 05:15:27 PM by KD303 »

Offline KD303

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« Reply #17 on: November 16, 2005, 05:20:09 PM »
Tony, perhaps you know how the Rolls Royce 40mm BF gun used on some Hurricanes compared to the Vickers 40 mm S gun? I'd be interested if you do.
Thanks.

KD

Offline Tony Williams

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« Reply #18 on: November 17, 2005, 03:08:58 AM »
Quote
Originally posted by KD303
I suppose it was decided that rocket firing Typhoons were more suitable for the job, and I'd be inclined to agree.


The big advantage of the Typhoon was that it carried four 20mm Hispanos as well as the RPs (the Hurri IV only carried two .303s). This made it a far more flexible attack vehicle and it could also defend itself against enemy fighters.

Quote
I haven't seen reports of Hurricane IVs using the S gun with the Mk IV from UK bases though it would seem it did happen. I'd be very interested to know more.


If you can get to the National Archives, look up AIR 16/705 which deals with this (I went before they allowed digital cameras, so I only have my own brief notes).

You will find the analysis of the effectiveness of weapons in ground attack in AIR 2/7816

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An aside - On the subject of 25lb solid head RPs, my Uncle flew for the Banff Strike Wing against shipping in Norway and said that they favoured the solid head for holing ships below the waterline.


I have read that if the RPs fell short and hit the water, they tended to level out and skim along just under the surface. This was particularly useful against U-boats, which made very small above-water targets.

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I have some good gun camera pictures from him in my collection which I MUST get around to posting.


Yes, you must!

Quote
Tony, perhaps you know how the Rolls Royce 40mm BF gun used on some Hurricanes compared to the Vickers 40 mm S gun? I'd be interested if you do.


The RR gun was never used operationally. It was tested in the Hurricane with good results (there is a comment on this in the AIR 16 report mentioned above) but by then Vickers were turning out sufficient S Class guns for the RAF's needs, so RR were told to give up on guns and get on with making engines. A simpler,. manually-loaded version of the gun (the BD) was issued to the RN for use in patrol boats, but the clever light-alloy construction showed a disconcerting tendency to blow up every now again, so perhaps it's just as well...

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Offline KD303

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« Reply #19 on: November 17, 2005, 08:00:07 AM »
Thanks for all the info, Tony. I'm in NE Scotland, so I don't get to the PRO or any London based archives nearly as much as I'd like.
Yes, I'd heard that, at that time, RR were told to get on with Merlin production as a top priority. I wasn't sure if it (RR's gun) had been used on ops.
I'm surprised to hear that the RPs skipped off the water. I must check that out!

KD

Offline Tony Williams

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« Reply #20 on: November 18, 2005, 02:33:12 AM »
Quote
Originally posted by KD303
I'm surprised to hear that the RPs skipped off the water. I must check that out!


No, they didn't skip off the water, they skimmed along just under the surface like a torpedo!

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Offline KD303

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« Reply #21 on: November 20, 2005, 06:07:45 AM »
Ah, I re-read what you said. Yes, that I had heard about. Sorry, I should have read what you wrote! It did seem rather unlikely - bouncing rockets. Mind you, there were experiments with rocket propelled bouncing bombs...The germans tried those out.
« Last Edit: November 20, 2005, 06:34:43 AM by KD303 »