3in and 3.7in "CS tank" howitzers

Discussion in 'Weapons, Technology & Equipment' started by phylo_roadking, Feb 14, 2014.

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  1. Sheldrake

    Sheldrake All over the place....

    Hang on.a minute. What are you doing this? Military procurement does tend to follow some logical rules. It takes a lot of time to time and money to develop new artillery pieces and ammunition. The armament for CS howitzers wasn't the most important aspect of the design of these AFVs. The British Army was happy with the 3.7" howitzer and the performance of its ammunition. .Tony has already pointed out that they use the same cartridge. Why on earth would someone want to design a special ammunition to be used by a small minority of tanks, that uses the 3.7" howitzer cartridge? Unless there is some documentary evidence of a separate development - which should leave a paper trail, it seems reasonable to assume as a null hypothesis that the CS tanks used the standard 3.7" howitzer. It is up to you my friend to find some evidence that they are not the same .

    PS the Centaur "tanks" landed on D Day were used as SP guns mainly in the indirect role after D Day - despite the fixed charge round limiting their effectiveness in close country with lots of local crests.

     
  2. DavidW

    DavidW Well-Known Member

  3. DavidW

    DavidW Well-Known Member

    Phylo that sounds interesting!
     
  4. phylo_roadking

    phylo_roadking Very Senior Member

    Yes it does - but notably the 3.7in tank howitzer was only ever fitted to Vickers designs from the 1930s....the A9, A10 and A13 - and before them the Medium MkIIA CS.

    So if anything it's likely it was a Vickers product....

    It was happy with the 3.7in mountain howitzer...but from 1939-on all NON-Vickers' desgned tanks that had CS versions used the 3in howitzer. And production of IT in the end vastly outnumbered the earlier 3.7in tank howitzer.

    Here's the thing...

    QF 3.7in mountain howitzer - from Hogg&Thurston
    muzzle velocity 973 feet per second


    QF 3.7in tank howitzer- from Chamberlain&Ellis
    muzzle velocity 620 feet per second

    The tank howitzer installation has a longer barrel, so surely if it is the same round firing in otherwise the same gun, shouldn't have the higher muzzle velocity?

    I'm not trying to prove anything one way or the other - I'm trying to find out IF it's the same weapon.

    If it is - fine....if it isn't, equally fine. But so far there's absolutely ziltch saying it is or isn't....and I'm choosing to make no assumptions, I want to know.

    P.S. as for the paper trail, I've been through the catalogue of Vickers' correspondance at Cambridge, and theres' nothing in there regarding this weapon. Nor anything specific turning up in a catalogue search at Kew.

    Sadly, there's no internal turret pics of a 3.7in-equiped CS tank around. If Bovvie have ever let a member of the public clamber inside THEIR A10, they didn't take a camera with them. So we can't just compare the two guns...NOR does there seem to be any manuals about dedicated to the CS types alone that might have had some illustration, if only in the stowage diagrams. Even the available illustrations of the Churchill MkI manage not to show anything useful of the 3in installation!

    (which leaves aside for the moment of why so many secondary and tertiary referecnes....and ONE primary account!...SAY that the 3.7in howitzer CS tanks couldn't/didn't fire H.E.....)

    Yes, I know about the comments in The Flames of Calais and Montefiore's Dunkirk about the Cruiser CS's landed at Calais having sailed without their H.E....but then there's THIS....
     
  5. phylo_roadking

    phylo_roadking Very Senior Member

    David - there is indeed a reference to a CS tank "event" in COMPASS buried in the legendary George Forty's "The First Victory"...

    It's about the taking of the Italian fort at Sidi Omar on the 16th of December 1940, before Bardia...and when most of the references about CS tanks in Cyrenaica talk about them being "embarassed" by the lack of H.E. - I didn't realise they LITERALLY meant embarassed...

    To ram the point home, the passage is footnoted at the end of the chapter...

    So....circling like fort like a bunch of indians with all small arms firing...and no H.E. for his tank to fire - even when faced by an Italian gun!
     
  6. DavidW

    DavidW Well-Known Member

    How interesting that he describes it not as a gun or howitzer but as a smoke mortar!

    Much like a 2pdr armed Matilda might have it's smoke grenade launchers described!

    So what do we conclude? No H.E in 1940?
     
  7. phylo_roadking

    phylo_roadking Very Senior Member

    Well, the 3.7incher is the one described as a "mortar howitzer" in C&E!

    Certainly they weren't carrying any...and there are plenty of secondary and tertiary sources that say the 3.7in could "only" fire smoke.

    But as debated elsewhere, does this mean it "couldn't" - or that it "didn't"...?

    Manuals for many types of British tank don't seem available commercially, and anyway I'd rather NOT start spending good money on downloads unless I was sure I was going to find "CS" version details in them. I suppose it would mean a trip to Bovvie to see what they have in their achives...

    But whichever...it certainly looks as if the doctrine of CS tanks hadn't yet broken down as of December 1940...

    It ALSO raises the question of if 3.7in H.E. was available as per the above from Tony - why weren't they using it, if only a few rounds per tank? Again, doctrine could explain that for a while - it looks like 1941 into 1942 therefore was the "learning time"...?
     
  8. DavidW

    DavidW Well-Known Member

    Yes, the question of ammunition and if it was the same would seem to me to be of critical importance as there were at the time 3.7" Howitzers in the Western Desert with 4th R.H.A at the very least.
     
  9. phylo_roadking

    phylo_roadking Very Senior Member

    Yep, there's still something missing from this tale...
     
  10. Sheldrake

    Sheldrake All over the place....

    It was happy with the 3.7in mountain howitzer...but from 1939-on all NON-Vickers' desgned tanks that had CS versions used the 3in howitzer. And production of IT in the end vastly outnumbered the earlier 3.7in tank howitzer.
    Here's the thing...

    QF 3.7in mountain howitzer - from Hogg&Thurston
    muzzle velocity 973 feet per second


    QF 3.7in tank howitzer- from Chamberlain&Ellis
    muzzle velocity 620 feet per second
    ...

    Fair enough. I had forgotten I had already comment on that. Here is a hypothesis. The 3.7" Howitzer and 3.7" Mortar use the same cartridge case and round but a bit less propellant so the recoil system can fit in a tank turret not designed to take a bigger gun than a 2 pdr and with no requirement to fire at longer range than the 2 pdr would engage a target,

    A second hypothesis is that one reason for the absence of a paper trail is that the CXS Howitzers were a poorly thought through product of the muddled thinking that characterised pre-WW2 British Armour doctrine. In the run up to the war and early war years it was well down the priorities for the army and the defence industry.

    Among the few references to these weapons in action is their uselessness in 1940 and the absence of useful ammunition - which is a clue to the priority given to it! The reason why there may be fewer mentions of them in 1941-42 because they were irrelevant. They lacked the range to be any use to engage German AA and Atk guns, and Sqn HQ tanks had a command rather than close support role in action. The tactical solution lay in better co-operation with their supporting Gunners. A Battery of 25 Pdrs and their dedicated OP and CP parties was far more use than two short ranged howitzers per squadron. By contrast I have just been reading the DCM citation of the remarkable Bill James of L Battery who was a WO2 BSM OP Officer highly regarded by the tank units his Troop supported.
     
  11. Tony Williams

    Tony Williams Member

    I have read that the Royal Artillery was rather possessive about owning all HE-firing artillery and objected to tanks being equipped with them as they would then have no control over their use. Hence the general non-availability of HE shells in British tanks, until the US 75mm gun came along.

    Maybe that's just a WW2 army legend, though.
     
  12. idler

    idler GeneralList

    There may be something in that but, on the other hand, I'm not aware that the Royal Tank Corps ever put up much of a fight to have an HE capability. I understand that the RA developed the tank guns, so perhaps there is a paper trail that mentions other natures in the development: did RA offer HE or not, and did RTC/RAC decline or were they denied?
     
  13. phylo_roadking

    phylo_roadking Very Senior Member

    Well, I do know (from some of Fletcher's other articles) that the "debate" over who owned what plagued the Churchill Gun Carrier project (slowed it down considerably, and the few available pics show Carriers with T- and then S-numbers! So they moved from one arm to the other during their brief lifetimes...)....AND the service/use of the Bishop IIRC.
     
  14. phylo_roadking

    phylo_roadking Very Senior Member

    I'd thought about that, and yes it's a possibility... reinforced by the fact that if there was one thing that there was plenty of in North Africa it was standard 3.7in mountain howitzer H.E. ;) So something prevented that being used.

    While I can certainly see this as applying to the nearly transparent 3.7in weapon...the 3in weapon is a very different kettle of fish; in fact, according to Postan's British War Production the 3in tank howitzer became a matter of considerable concern because supplies far undercut demand! As we know, "the MkII" Churchill came about because there weren't enough 3in howitzers coming through quickly enough.

    The priority - or the intended use??? In the course of this being discussed elsewhere I've come across some VERY interesting factlets on the CS tanks...

    The doctrine of them providing smoke as their primary role didn't die off as some people have suggested - in fact, the army tank brigades were only authorised CS tanks on the 11th of April 1941! Which accounts for the spike in Matilda III CS production in late 1941/early 1942, as well as the Soviets requesting them...all the Valentine-armed units in the British Army got Matilda III CS tanks for their CS role.

    As an example - the now-legendary 33 Matilda III CS' sent to New Zealand and robbed of their guns to fit the New Zealanders' Valentines were originally sent to provide a CS tank for the aforementioned NZ Valentines...but they didn't want a mixed force of tanks so THEY went to the labour of making the Matildas' 3in howitzers fit the Valentine!

    As late as early 1943, Gerry Chester's North Irish Horse were sent Churchill MkI CS and MkII CS tanks from the UK...because of course they were busy re-arming with MkIII 6pdr-armed Churchills - for which no smke round was available ;)

    In other words - it appears that right into 1943 at least, as long as there was a need for "organic" smoke provided by tank units for themselves...the "CS tank" role was seen as the answer.



    As for "The reason why there may be fewer mentions of them in 1941-42 because they were irrelevant" - irrelevant....or just transparent to us? ;) If it was absolutely normal for CS tanks to throw smoke from their 3.7in/3in howitzers to cover the movements of the rest of their squadron...would it actually BE mentioned in war diaries etc.? If it was that normal, it wouldn't merit any jotting-down.
     
  15. idler

    idler GeneralList

    From Andy's Conversations with Montgomery thread: a conversation between Liddell-Hart and Hobart about GOODWOOD.

    The penultimate paragraph is interesting - possibly even relevant - given Hobart's history, a real throwback to the 'armoured' CS concept:

    [​IMG]
     
  16. phylo_roadking

    phylo_roadking Very Senior Member

    That's a great find! The penultinate paragraph is very relevant too...

    It's been said so many times in debates online on the CS tanks that artillery could make up for any deficit on the part of CS tanks - except when it couldn't for whatever reason - does that look like a liaison issue??? Certainly the LAST paragraph indicates a failure - but whether to identify the need/request smoke in the original planning, or on the day isn't clear :(


    Didn't? Or by this period couldn't? I note the paragraph dealing with how 7th Armd Div's Italian experiences governed their behaviour that day...I wonder how their CS capability looked by 1944 compared with 1943 and earlier?

    In the last paragraph it certainly looks as if it's couldn't...

     
  17. idler

    idler GeneralList

    I'm not sure which way to jump on mid-war CS capability. In Sherman-equipped units, all tanks were capable of chucking HE and smoke about the battlefield, so there was no need for a CS variant (though the US had their 105mm Shermans). The question becomes: how much smoke ammunition was made available.

    Hobart's smoke comments seem, to me, to hark back to pre-war tactics, so there is a question of how relevant they were in practice. No doubt that's how he trained his 11 Armd Div up to Sep 1943, so perhaps some of their units have made comments on their training versus their combat experience?

    Following this line of thought, there is a little quote in Delaforce's Black Bull by a troop corporal in 2 Northamptonshire Yeomanry (Cromwell 75s):

     
  18. phylo_roadking

    phylo_roadking Very Senior Member

    Well - the doctrine seems to have been identified during the Experimental Mechanized Force exercises, and carried on through the couple of years of subsequent "Mixed tank brigade" exercises - for the fitting of howitzers....first to MkI and MkIIA Vickers Mediums dates from that period.

    The concept doesn't die with them - so SOMEONE must have though CS tanks worked! AFTER that we have the various 3.7in-armed Vickers-designed cruisers...and in 1939 the 3in howitzer starts being installed in NON-Vickers designed tanks.

    Wind forward by anecdote and brief mentions - such as the Army tank brigades specifically being given them in early 1941...and we eventually reach the Spring of 1943 - when the North Irish Horse was given MkI CS and MkII CS Churchills after the fighting in Tunisia was done. BEFORE that, the MkI gun tanks provided their own smoke in Tunisia.

    The NIH CS tanks were often used for smoke in Italy...and they didn't arrive there until September 1943 IIRC! So far from being a pre-war tactic, the CS doctrine was certainly a "live" doctrine just under a year before the events documented above.

    Ditto for the North Irish Horse IN Tunisia, of course ;) While they received their first MkIIIs there, the MkI with its 3in howitzer still made up the majority of their tanks until re-arming was completed AFTER the fighting...

    ...and Gerry's account notes that the MkI gun tanks carried a 75%-25% ammo mix as compared to the 100% H.E. the MkI was supposed to carry in its racks when it first came into service in the UK ;)

    Add the Shermans and their lack of accompanying CS tanks...to the North Irish Horse and their NOT getting proper CS tanks until the 6pdr-armed tanks couldn't throw smoke...and it's starting to look as if the "CS" role was the preferred solution for tank units providing their own smoke until quite late in the war!

    What I'd like to find out now is the ammo loadout of tanks like the Cromwell VI with its 95mm howitzer ;) With IT providing close support after D-Day, the HE/smoke division of its loadout might give a clue as to what was expected of it....
     
  19. idler

    idler GeneralList

    Definitely - Military Training Pamphlet No.41 Part 2: The Armoured Regiment, February 1943 has a number of squadron 'battle drill' diagrams in the back, all of which show the CS tanks screening enemy posts during attacks. I don't doubt that the concept lasted through the war, but can't help wondering how long the it lasted in practice. Compared to Parts 1 The Armoured Division and 3 The Motor Battalion, Part 2 has always struck me as a little bit unrealistic, particularly as it maintains the pre-war analogy of 'fluid' tank-on-tank engagements and naval warfare.
     
  20. TTH

    TTH Senior Member

    I am not an armored doctrine expert so I don't know what US Army manuals said, but I do know that US tank battalions included an 'assault gun platoon' equipped with vehicles armed with 75mm or 105mm howitzers. In 1943-44 these were the M8 HMC (75mm how on M5 Stuart chassis) and later the M4 Sherman with a 105mm howitzer in place of the 75mm or 76mm gun. In Tunisia and Sicily I think the T30 and maybe the T19 and M7 HMC's were used in the assault gun role. Postwar, US tank companies had a couple of 105mm howitzer tanks at company headquarters. So the RAC wasn't the sole believer in the CS idea.
     

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