Wednesday 6 June 2018

A-20 Characteristics

"A-20 tank (convertible drive)
September 10th, 1939

Tactical-technical characteristics of the A-20 tank
(Convertible drive with 3 powered pairs of wheels)
  • Mass: 18 tons
  • Length: 5.7 meters
  • Width: 2.65 meters
  • Height: 2.36 meters
  • Armour: 25 mm or equivalent in toughness
  • Armament: one 45 mm gun, two DT machineguns
  • Ammunition: 160 45 mm shells, 300 machinegun rounds
  • Crew: 4
  • Cruising range: 350-400 km
  • Engine: 500 hp V-2
  • Top speed: 75 kph
  • Mobility:
    • Maximum grade: 40 degrees
    • Widest trench: 2.4 meters
    • Maximum fording depth: 1.2 meters
The tank has travelled for 4200 km during the course of factory and proving grounds trials. The trials revealed the following:
  1. The side friction clutches and brakes need to be reinforced.
  2. The idler mounting should be changed.
  3. The ball bearings on the wheel drive reductor should be reinforced.
  4. Visibility from the tank needs to be improved by installing additional observation devices.
Marshall of the Soviet Union, K. Voroshilov"

"Decision of the ABTU RE: A-20 tank

The A-20 tank has significant advantages over the existing BT tanks due to its engine, usage, and combat characteristics. Factory #183 must produce a pilot batch of 15 units by January 1st, 1940. Before then, correct all defects discovered during trials and reinforce the front plate to 25 mm and the front part of the floor to 15 mm.

Chief of the ABTU, Corps Commander Pavlov
Military Commissar of the ABTU, Brigade Commissar Kulikov
September 15th, 1939"


  1. What's sad is except for the "convertible drive aspect"this rejected A-20 was better than almost every tank under construction in the west.

  2. That's true....and of course it was one of the immediate predecessors of the T-34.

    1. And yet I see why they sent it back to get rid of the convertible drive aspect. I bet it must of been hard as hell for the tankers to roll up that track and put it on the hull whenever they planned to drive on wheels. As such I doubt they used it much. Plus I bet the final drive lasted better when elevated instead of being the last road wheel. But to be honest the 45mm was more than good enough by even 1941 standards. And there must of been a lot more room in the turret than when they added the 76mm. Though the 76mm did come in handy the rest of the war.

    2. The 45 mm wasn't going to be good for much longer though, which the Soviets could doubtless predict based on their own next-gen designs, and the 76 mm was both fairly "future proof" and rather better at blowing things up with its far more potent HE shell as it was. No wonder they scaled up the design to fit in the bigger gun.

      I wonder if their misplaced worries about terrible Capitalist supertanks had any impact on the matter?

    3. Those worries materialized more in prospective designs on the KV chassis rather than the BT/A-20/T-34. See stuff like the KV-4, which was a whole collection of possible designs with a 107mm ZiS-6 and a 45mm 20K gun in mixed casemate/turret, turret on top of turret, turret with both guns coaxial and whatever other combination you could possibly think of.

    4. Killomies If the Soviet's truly understood free capitalist nations they would of realized that in peace time most of our industry is working to satisfy the public's needs.

    5. Well sure, but obviously a 76 mm is a lot more useful than a 45 mm against the hypothetical heavy ironmongery in your line tanks. Flank fire and just trying to shoot off the tracks are a thing after all.

      And I think the Soviets had no shortage of informants and spies keeping them up to date on the social and economic conditions inside the "Imperialist powers"; what they had a much fuzzier picture of was what the Hell the militaries were up to, as those tended to have pretty strict security and were difficult to infiltrate.
      Cue longstanding alarmism over an Europe supposedly crawling with diverse imaginary bogeyman tanks, or the modernisations the Finns did on the plentiful coastal artillery they inherited from Imperial Russia catching the Soviet navy quite by surprise...

    6. Killomies While England, France and America were overrun by individuals willing to send information to the Soviet Union, I suspect the Nazi's cracked down on the Communist to the degree that Russia really didn't know for sure what Germany was up too. I believe their reports that they were insulted when the German's showed them their latest Pz. Kpfw. 3 and 4s. To be fair I suspect the Soviets underestimated the value of good radios and crew ergonomics. German's given the choice in 1939 might of liked the T-20 and added better hatches and vision slots. But looked into enlarging the turret for a three man crew. The country that could of used the T-20 the most was France. They put so much money and effort into designing tanks that just weren't good at fighting.

  3. The Soviets had functioning spy cells inside Germany well into the war, IIRC - as usual the people involved were not openly Leftist and hence automatically suspect.

    More to the point in autocratic regimes political decisions are made behind closed doors by small groups of people, or even just the autocrat himself; those outside such rarefied cliques are left to making educated guesses based on visible policies, public declarations and no small degree of divining from subtle hints (compare the "Kremlinology" of Cold War).
    And militaries universally not only maintain strict security regimens and serious compartementalisation of information but also, outside revolutionary states like the USSR itself, have permanent staffs more likely than not to lean towards conservative-patriotic "Right wing" political sympathies. The very nature of the work tends to attract men with such valuesets into the professional officer corps which alongside much stricter screening than in the civilian sector obviously made it extra difficult to slip in Communist agents, and even locating sympathisers (or just sufficiently corrupt individuals) willing to leak information was a challenge - nevermind now ones that had any access to the more hush-hush R&D side of things.

    As far as radios go keep in mind that the ability to furnish your military with those was directly dependent on the size and sophistication of your electronics industry, which in turn was heavily dependent on its peacetime civilian market share. For example the French were latecomers to the field and the market was already saturated with British and American sets; and as a responsible democratic regime they needed to actually balance budgets and pursue sustainable economic policies and couldn't simply pump massive state subventions into the industry for propaganda and military purposes heedless of long-term fiscal viablity, as the Nazis (who expected to conquer their debtors in a few years and duly thumbed their noses at sane economic policy) did with their wildly successful "Volksfunken" program.

    Conversely the Soviets were still very much playing catch-up in electronics, not surprising given the breakneck bootstrapping of the entire national industry in barely two decades and the degree of sophistication demanded by such highly refined technologies. Case in point the T-34 was designed with a radio station from the start but it wasn't until about '42 (IIRC the relevant article on this site) that production of the planned sets caught up with the output of the tanks - apparently early on it was duly common to simply leave the somewhat idle radio operator position empty, use the bow MG elsewhere and unceremoniously plate over the opening in order to economize manpower.

    Also French tanks were decent enough at what they were designed for - *when they could actually be used for their intented roles*. The real problem was that serious failures of generalship forced them to fight ad-hoc on the Germans' terms in circumstances most of them weren't particularly good for. That critical fuckup at Sedan set in motion a succession of disasters that first all but crippled the French military and then knocked it out of the war before they could meaningfully debug their tactics and gear (though not for lack of trying, as the Germans found out the hard way over the first week of Case Red) and basically gave Hitler free hand on the continent. Also convinced Mussolini to finally commit to the war with rather far-reaching consequences...
    The French commanders of '40 have a lot to answer for and it's honestly surprising how little attention that early critical turning point gets in alternate-history scenarios. Then again I suppose the Germans being checked on the Meuse and systematically worn down in a rerun of the Great War wouldn't make for a very dramatic story...

    1. Oops, clicked the wrong "Reply" button. Oh well.

    2. Thank you. I was always under the impression that Germany was feeding Russia false information and as a result Stalin didn't trust anything his own people told him. Nor had I heard about T-34's plating over the radio operators position. Could this also of been because the shortage of machine guns? I figure the infantry needed the DP Machine guns more than the T-34 needed it's bow gun. Sure a lot easier to drag around as opposed to 130 pound M 1910s And as you bring up, I wouldn't be surprised if he handed rounds to someone in the turret to speed up the rate of fire of the main gun. Unless he could actually fit there. I know the British managed to get three men into their Matilda tank turrets. Could a third guy of squeezed into a T-34/76 turret?

    3. Near as I recall reading about it the main point in leaving the operator out of the radio-less T-34s was simply manpower savings. This was after all a period when the Red Army was operating in pure hand-to-mouth crisis survival mode and had a desperate need to get as many combat units to the front as possible ASAP - and the bow MG wasn't exactly a critical part of a tank's combat power anyway. (Indeed during the war everyone but the Americans with their fixation on moar dakka realised it was almost useless - literally worse than useless once the edge effect was understood.)
      Leaving the for-now unnecessary radio op position vacant meant a 25% manpower saving and that man could be trained to do something more immediately useful instead, though I suppose 50% savings in MG-per-tank didn't hurt either.

      I'm no expert on the internals of the T-34 but from what I know of it repurposing the radioman into turret assistant doesn't seem terribly viable. You'd pretty much have to rip out his seat (which would raise a slew of new issues) for him to be able to even get at the relevant parts of the interior and as I understand the ammo stowage system used he'd mostly just be literally underfoot once there...

    4. Kellomies Are you implying that giving early M-3 Stuart's 5 30 cal. Machine guns is overkill? LOL

    5. Never! Such an un-American idea, what manner of commie mutant traitor are you? >:C

    6. There is no problem that cannot be solved by superior firepower!