3.7" A.A. gun, RAF Hendon museum - am I missing something?

Discussion in 'Royal Artillery' started by HAARA, Dec 6, 2014.

  1. HAARA

    HAARA Well-Known Member

    I had the rare opportunity, living some miles away for an easy visit, to visit RAF Hendon recently, and to see the Battle of Britain exhibition. Amongst the exhibits is a 3.7 Vickers, in a tableau setting, I think, possibly, to give the impression of the gun in use. I was interested to note that the outriggers were deployed, and the barrel traversed as elevated, but that the wheels were still attached, as photo. I was under the impression from what I have read about the 3.7" that wheels were taken off when the gun was in action (although I believe that on Mk 1 they were raised as a counter weight). Am I misinformed, or was it possible to use the gun as displayed?

    The gun also seems to be devoid of gun layers' seats (and sights), or, again, am I missing the point here?

    Attached Files:

  2. Smudger Jnr

    Smudger Jnr Our Man in Berlin

  3. Owen

    Owen -- --- -.. MOD

    Maybe the fact that it's in a museum & may have to be moved about now & again has something to do with it.
  4. CL1

    CL1 116th LAA and 92nd (Loyals) LAA,Royal Artillery

    It's a bit tight in there where it is located and very dark
    I think space is the issue
  5. mapshooter

    mapshooter Senior Member

    Leaving both pairs of wheels seems a bit unusual, but removing the pair with the towing eye to the rear of the gun and leaving the other raised and attached seems fairly normal. Lack of seats probably depends on whether the layers were laying by aiming at the target or by matching the pointers (ie the pointer for where the gun was pointing and where the predictor data showed it should be pointing).
  6. redmist

    redmist Junior Member

    One could, of course, buy one's own then deploy it just as one wished :)

    CL1 likes this.
  7. HAARA

    HAARA Well-Known Member

    Thanks guys - I think I tend to concur with the "it's a museum display" comments above. The following was my prior understanding:

    Two configurations of the Vickers 3.7” QF gun were produced, mobile and static. Mobile guns used a limber and carriage configuration each on two pairs of inflatable tyres, with four folding outriggers with levelling jacks. The carriage wheels to the front of the gun were raised when the gun was brought into action, and used as counterweight. These could alternatively be removed, as with the rear limber set, this becoming standard practice later in the war. The gun mounting required to be precisely levelled before accurate firing could be achieved.

    In a ground shooting role the guns were usually positioned in temporary pits, wooden pickets up to 4 feet in length being driven into the ground around the mounting to prevent the gun from slewing or shifting, this being a frequent problem due to the recoil when using a gun at low elevation. This did not, however, prevent the gun ‘jumping’ when fired and the resultant potential for the gun to move out of position, the gun requiring regular re-levelling and calibration. It was also recommended that gun mountings be regularly rotated to minimise wear due to the gun recoil.
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  8. mapshooter

    mapshooter Senior Member

    The static mounts actually had wheels available for when the guns were moved, but not a set for every gun. The mobile mountings were basically for use by the field army. AA laying was normally by pointer matching using data automatically and continuously transmitted from the troop/battery predictor. However, some photos from the earliest years do show laying with visual sights and I think they were always available as back-up.

    For field use the guns were eventually modified to take field artillery sights with normal field artillery procedures and orientation by director. Normal field artillery practice is to relay the gun after every round fired. This means ensuring that the sights are still levelled and pointing at their aiming point, the sights have their own levelling but to bring them back on to the aiming point if required means using the handwheels to elevate or depress the ordnance and to move it left or right. Calibration is an entirely different matter, and is done periodically, its purpose is to obtain a new muzzle velocity by firing instead of just relying on a count of rounds fired or even physical measurement of barrel wear. The MV is used in the command post to calculate firing data unless the gun has calibrating sights, which all UK design WW2 field arty did.
    CL1 likes this.
  9. HAARA

    HAARA Well-Known Member

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  10. TTH

    TTH Senior Member

    Thanks for some very enlightening info about the 3.7, especially in the ground role. Not long ago we had a thread about 'why wasn't the 3.7 used as an AT Gun in the Desert?' What we have, it seems, is a very big and conspicuous gun initially without proper sights for ground shooting, which tends to shift, skew, and even jump when fired at low angles. That doesn't sound like an ideal anti-tank gun to me. Did the Germans have similar problems with the 88?
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  11. CL1

    CL1 116th LAA and 92nd (Loyals) LAA,Royal Artillery

    TTH well remembered link below

  12. hutt

    hutt Member

    Interesting if rather grainy video of these guns in use against V1 weapons. Rate of fire phenomenal!

    (around 1 minute in)

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  13. CL1

    CL1 116th LAA and 92nd (Loyals) LAA,Royal Artillery

    Hutt thank you for posting
  14. Mike L

    Mike L Very Senior Member

    Great Pathe film Hutt. The Critical Past one is pretty good too.

    Nice to see the well oiled teams feeding the guns but I suppose they had a bit of practise by then!
  15. mapshooter

    mapshooter Senior Member

    By the time V1s were a target, Mechanical Fuze Setter No 11, mounted on the gun and taking data from the predictor, had been added to the static guns and some mobile guns. This enabled a significantly higher rate of fire because the cyclic rate was more predictable and fuze setting was faster. That said, VT fuzes were also available and did not need fuze setting (CVT did not enter service until the 1950s).

    Re 88, it is often forgotten that there were both PAK and FLAK versions, although both PAK versions were a lot bigger than a 17-pr.
  16. Trux

    Trux 21 AG

    Some more or less relevant snippets from 76 AA Brigade, Gold, June 1944.

    HAA Site 24 (‘A’ Troop, 366 Battery, 113 HAA Regiment) was linked by line to Regimental Headquarters 7 Medium Regiment so that the guns could be used in the ground role. Information was to be routed as follows: Observation Post – 7 Medium Regiment Gun Line – 7 Medium Regiment Headquarters – Gun Site 24 – Anti Aircraft Operations Room.

    1920. Corps Commander RA called for a Victor Target. Call passed to the AAOR and the target was engaged at 2015.
    2355. CCRA called for HF Target, 100 rounds on ref: 830702 from 2300 to 2359 hours. As there were air attacks at the time this was referred back to CCRA and the time was altered to 0130 to 0230. This was passed to AAOR and carried out.

    1450. A Harassing Fire task was called for by CCRA. This was passed to AAOR. 20 rounds were to be fired every 15 minutes until further notice. Firing stopped at 1555.
    CCRA asks for Harassing Fire, 100 rounds between 0200 and 0230, 100 rounds between 0400 and 0430. Task given to 99 HAA as they were the only guns within range.

    And so on.

    Later in June HAA units were asked to be economical in the expenditure of ammunition in AA fire and conserve it for ground fire.

    AA Brigade orders also stated that HAA guns should be sited for anti tank defence when possible. 113 HAA reported that it had four captured 88mm guns with anti tank sights fitted plus 50 rounds armour piercing ammunition, 300 rounds HE time fused and 200 rounds HE percussion.

  17. HAARA

    HAARA Well-Known Member

    Had a rummage through my National Archive files, and found the attached on ground shooting procedures in Italy, which I hope is of interest ( apologies, the attachments only want load in random order - had several goes at loading these, so read from the numbering in the file header!!!!)

    Attached Files:

  18. hutt

    hutt Member

    There is a reference on the attached diary page for the 16th June (12.00) 1940 to dud 3.7" and 3" ammunition. How exactly does 5400 rounds end up in that state at such a critical stage of the war and how would it have been discovered?

    Does anyone know what Mill Hill E A M refers to. Something something magazine I assume? There are other references to Hyde Park magazine scattered throughout this diary.

    Attached Files:

  19. TTH

    TTH Senior Member

    Well, I am just guessing, but the 3" was an old weapon due for replacement, so I would think it quite possible that a lot of the ammo for it had been stored for years and was not in prime condition. The 3" was also used in large numbers by the BEF, so perhaps the more recently made batches of shells went to France, leaving home defense AA with older lots. The 3.7" was relatively new, so perhaps the factories hadn't yet got the hang of making shells for it. Quality control of war material was sometimes a problem after 1940 as well. The Crusader tank, the Sten, and trucks are other examples.
  20. mapshooter

    mapshooter Senior Member

    There are various components to a round of ammunition, made in different factories. 'Dud ammo' is meaningless.

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