The Butterfly Effect: A British AAR

Chapter XCII: A Scottish Restaurant Menu of Tanks​

In comparison to their heavy brethren the men of the cruiser branch of the Royal Armoured Corps had not one but three designs to consider in the spring of 1937, each designed and built to a different specification. While this did give them a chance to review decidedly different interpretations of what exactly a Cruiser Tank should be, this was not the original intention. As with the A11 Matilda we start in 1934 though a few months earlier, hence the first two tanks under consideration, the imaginatively named Cruiser MkI and Cruiser MkII, bearing the General Staff designation A9 and A10 respectively. The two tanks were stable mates and shared many components from the turret on top down to the mechanicals, the differences being effectively confined to armour and armament. While the A9 was always intended as a cruiser design the A10 began life as an infantry tank, only being assessed as a cruiser after it's inadequate armour disqualified it from the infantry tank role. While it would be nice to think this use of a common design was a deliberate choice driven by thoughts of simplified logistics and maintenance, in truth it was a pure economy measure, one of several that would blight both tanks. It would however be unfair to entirely blame the Treasury for the problems of these designs, certainly their economy measures did not help but the then Royal Tank Corps (RTC) should not be absolved of their mistakes, the A9 and A10 in particular were ill-fated from the start.

The A9 was a RTC original, unlike the Matilda which had originated from the Army Board the A9 project had involved the RTC from the start, which was something of an indictment in itself as the first predecessor of the A9 could be dated back to the mid-1920s. Simply put the A9 was a refined version of the aborted Vickers A6 / Medium MkIII, a design that had been in development since 1926 and had been cancelled due the high unit cost of the final production prototype. While the evolution had markedly improved the design there is a very strong argument that a fresh piece of paper would have been a better choice, certain fundamental problems had never been cured despite years of work. However the RTC would not be deflected and it appears their decision to go ahead with the A9 was not based on a rational judgement of what the Corps needed or wanted, but what it had been denied by the Army Board. While this was bad enough the RTC made matters worse by going along with the cost cutting measures imposed on the project, doubtless determined to avoid the mistakes of the 'over-priced' Medium MkIII. Thus not only where the worst features of the past preserved but whole new problems were added to the design.


The most obvious problem with the A9 was the triple turrets, an inheritance that can be traced all the way back to the Vickers A1E Independent, the tank that had started the multi-turret mania back in the 1920s. Quite aside from the marginal value of two turreted 0.303" Vickers machine guns on a tank that already had a 2pdr main gun with a co-axial 0.303", the two 'sub-turrets' were deeply unpopular with the cramped crews who had to man them and compromised the armour scheme of the tank, creating numerous shot traps and weak points. These weaknesses took on critical importance as the A9 was hardly well armoured to start with, having a mere 14mm at thickest on the turret and front hull with only 10mm or less elsewhere it was about as well protected as a Light Tank MkVI; basically machine gun proof but little more. Moving downwards the mechanicals were little better, economy measures had seen the MkIIIs Armstrong Siddeley V8 replaced with a string of inadequate 'commercial' engines and had forced the designers to retain the tried and failed coil spring triple-bogie suspension system, leaving the tank underpowered and suffering with severely compromised off-road performance and the alarming tendency to shed it's tracks under load. A brutally honest assessment would conclude that the Light tank Mk VI had superior speed, better suspension, better reliability, a lower cost and, due to the lack of 'sub-turrets', effectively better armour. The only advantages the A9 had over it were it's powered turret and the 2pdr main gun it contained, not insignificant but hardly the vast improvement that the RTC needed to regain the lead in tank design Britain had frittered away in the 1920s.

The case of the A10 is somewhat more complex, intended to serve as an infantry tank the basic A9 design had it's armour was thickened and, interestingly, the two sub-turrets removed. That aside the design was barely altered and used the same power train and suspension with equally bad results. On it's own terms the up-armouring must be judged a success, not only was the thickness doubled all over to 30mm turret/front hull and 22mm elsewhere but without the two shot trapping machine guns turrets the actual combat effectiveness of the armour was exponentially increased. Sadly the end result of these modifications was a design that fell between the two schools of the RTC; the infantry tank branch soon dismissed the A10 as being under-armoured, compared to the vast 60mm slabs on the Matildas the A10 was indeed paper thin, while the cruiser branch were concerned with the alarmingly slow speed of the design. With the same mechanicals as the A9 no more than 16mph could be achieved on the road and half that off it, hardly appropriate for a cruiser, even for a 'heavy cruiser' as the A10's supporters dubbed it. Despite these flaws both the A10 and the A9 were ordered by the War Office, the outbreak of war in North Africa prompted a minor panic at the lack of any deployable tanks (bar ancient Medium MkIIs and MG armed light tanks) and the War Office reacted by hurriedly ordering of the nearest new designs to hand; the A9 and the A10. After the unexpectedly rapid end to that conflict the larger 'on approval' volume production contracts were cancelled, but the initial trial orders were too far advanced to cancel, leaving the newly formed Royal Armoured Corps (RAC) with several hundred new tanks that they were less than impressed with and had no clear idea how to use.


The final tank under consideration was far more interesting, though sadly this did not extend to it's name as it bore the entirely predictable designation Tank, Cruiser, Mk III and was the product of the A13 specification. The A13 was the brainchild of Major-General Giffard LeQuesne Martel who, impressed by the Christie-derived BT tanks he had seen while observing Soviet manoeuvres, had arranged for the War Office to investigate a similar design. To this end a Christie M1931 tank had been acquired from it's developer, the American Walter Christie, imported and handed over to the Morris Motor Group for development. It was this original chassis that was under review by the RAC, the newly promoted Major-General Hobart having insisted his Corps have a say in any new tank design and to be allowed to compare it with the existing tanks then in service. With tanks and cavalry united in the RAC the traditional 'divide and conqueror' tactics of the Mechanisation Branch (and indeed the War Office as a whole) were ineffective and Hobart was able to insist on both more 'realistic' (i.e. tougher) trials and to get his own men present to observe. This was unfortunate for the A13E1 (E1 denoting the 1st experimental prototype of a specification) as it easily passed Martel's performance trials, recording tremendous speeds in the process, but was badly shown up by Hobart's longer distance reliability and combat manoeuvring runs, regularly breaking down and shedding tracks. As an added problem the armour, with a maximum thickness of 16mm, was considered too thin and despite a minimal 2 man crew it was clearly very cramped. On the positive side the 'Christie' suspension, for all it's faults and track shedding, was better than the suspension on the A9/A10 and the aero-engine derived Liberty L-12 engine was a success, though the revelation that a 340hp military grade engine was better than a 150hp bus engine should not have surprised anyone.

The two groups involved, Martel's Mechanisation Branch and Hobart's RAC, drew distinctly different conclusions from the trials. Martel still believed in the Christie concept and arranged for Morris to continue with their work, developing a localised version of the Liberty L-12 and revising the underlying mechanicals to improve reliability. By contrast Hobart believed the A13 to be an interesting idea, but ultimately too flawed to continue with and instead pushed for a new 'blank paper' design. Consistent lobbying, and an Army Board wary of ignoring serving tankers after the Matilda debacle, produced results for Hobart in the form of the A14 specification. Despite notionally being a fresh start the A14 in fact incorporated several old ideas, though in stark contrast to previous specifications these were actually successful ideas rather than failed ideas 'with promise'. Starting from the bottom up the tank was to use the Horstmann torsion bar suspension from the Light Tank MkVI, the massive 500hp Thorneycroft RY 12 marine engine that had been tested on the final Medium Mk III prototype and to have armour at least as thick as that of the A10 and, thanks to the mighty engine, the speed of the A9. Interestingly Hobart retained faith in the OQF 2-pounder, though the A14 specification demanded an increased ammunition load to allow large stocks of both HE (High Explosive) and AP (Armour Piercing) shells at the same time, experience in North Africa had forced the RAC to admit they couldn't afford specialised tank-killer tanks; battles refused to develop in the same orderly fashion as staff exercises.

The scene was therefore set for conflict between the Mechanisation Branch and the Royal Armoured Corps over design primacy, with the Army Board and much of the War Office caught between the two sides. Had the matter been merely technical it would have been bad enough, the conceptual differences between the two designs were not insignificant, however politics, of both the Army and Westminster varieties, would complicate matters. Just as an added twist the escalation of the war in Spain would present the British Army with additional (second hand) experience on armoured warfare, this time from a conflict where both sides had significant numbers of tanks to hurl into the fray.

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Notes;
A9 and A10 completely OTL including the RR car engine, the only change is that the A10 was dismissed by the infantry tank branch then ignored until '38 when it was reviewed again by the cruiser branch and became a 'heavy cruiser'. TTL the RTC just wants some tanks as there is a war on so makes an initial order and plans to sort out the details later, of course the war ends earlier than anyone expected so they get a chance to draw breath and think things through. The initial orders OTL were 175 and 125 respectively, I've just evened that out for neatness and to make the brigades work.

The idea of a RR Merlin tank engine was vaguely knocking around but never got anywhere for two reasons; 1. Morris (later the Nuffield Organisation) had a lock down on using their engine and no-one elses and 2. RR were far too busy making Merlins for the RAF. Now TTL Hobart is fighting 1 while 2 doesn't apply, RR geared up for full war production but now the war is over, it's not a big financial hit (they're probably ahead of OTL money wise) but no boss likes reducing capacity, hence I think they'd be more interested in another application of the Merlin. Particularly as I'm going to try and avoid the Merlin monoculture just for a bit of variety.

The A14 was an OTL(ish) spec, a heavy cruiser spec based on the Soviet T28 and about as successful. I've just had Hobart hijack it and remove the stupid twin front MG turrets. The 500hp marine engine was OTL, very successful but it was pricey compared to a bus engine so not popular, worse it suffered from not being a Nuffield design so they refused to use it. The Horstmann suspension was used and did work on light tanks and eventually ended up on the Centurion so it's a good option and I've decided to use it, which brings us onto the big problem; General Martel

Frankly I'm less and less impressed with Martel the more I read about him, he was borderline obsessed with the Christie pattern and did his level best to push that design to the detriment of other ideas. Christie suspension, while it was better than the A9/A10 design, wasn't that good, it was optimised for speed and not reliability. Everybody who used it had problems with losing tracks, even the T-34 suffered and crews would carry spare tracks because failure was that common. Equally the Nuffield-Liberty engine was underpowered almost from the beginning, certainly by the Mk VI Crusader it should have been obvious, yet Martel as head of the RAC kept supporting it for several generations onwards. It was only once he buggered off to Russia in '43 that things improved; the Sherman Firefly and the spec for the Centurion being the obvious ones. Thus for British tanks to advance Martel must be defeated, step forward Hobo your Corps and your country needs you!

Game Effects;
As trailed, 1 armoured cav division in production (using the A9 and A10s). I've also got a ARM II division in the UK representing the Experimental Mechanised Force, i.e. all the prototypes and various odds and ends being used to develop tactics and test new designs. Finally I've got a LARM in the queue but I can't remember why, it's been a while since I had to actually play the game to advance plot! My guess is that it's a way to represent all the light tank/armoured car units being unified under RAC control, works for me anyway.


Finally, apologies for not responding to the comments but I've been busy and figured you would all prefer an update as my top priority! Replies and vote tallying tomorrow, as I wouldn't want anyone to think I take all the comments (and Davouts songs ) for granted