Wednesday 18 April 2018

Clear the Air

"January 27th, 1941
Order of the People's Commissar of Medium Machinebuilding and People's Commissar of Heavy Machinebuilding

Stationary trials performed at factory #75 of air filters for V-2 tank engines produced at factories ##75, 174, and 183 showed that the air filters do not satisfy the requirements for air filters established by Committee of Defense decree #428ss issued on November 19th, 1940.

Considering the exceptional importance of equipping V-2 tank diesels with functional air filters, I decree that:
  1. Directors of factories ##75, 174, 183, the Kirov factory, STZ, and NATI must develop and test air filters for the V-2 diesel engine by March 15th of this year that guarantee at least 95% purity of air for 10-12 hours of work in dusty conditions without cleaning, according to the following parameters:
    1. Coefficient of air cleaning of 97-98% in conditions of 1 g of dust per cubic meter (dust with 0.006 to 0.020 mm grains).
    2. Loss of at most of 750 mm of water pressure (no more than 5% of power).
    3. A design that is simple to produce, reliable, and easy to use.
    4. A design that can be cleaned in the field by one person without special instruments in no more than 10-15 minutes.
    5. Moving the air filter from the engine to an unused part of the tank is permitted.
    6. If an oil bath filter is used, it must not permit the oil to get into the engine.
    7. The design of the air filter must be in cohesion with the air flow in the tank.
  2. Establish the following awards for the best air filter design for the T-34 and KV-1 tank:
    1. 1st place: 75,000 rubles
    2. 2nd place: 50,000 rubles
    3. 3rd place: 25,000 rubles
  3. The following commission is formed to test the developed air filters:
    1. Chair: M.M. Zatravkin (NATI)
    2. Members:
      1. A.A. Lavrushenko (GABTU)
      2. V.M. Kogan (GABTU)
      3. E.P. Dedov (Kirov factory)
      4. G.I. Nesterov (factory #174)
      5. Yu.B. Margulis (factory #75)
      6. Fedotor (factory #183)
        The commission is to develop the trials program, conditions of trials, location of trials, and condition of the contest, and present it to the People's Commissar of Medium Machinebuilding for approval by February 1st.
  4. Comrade Tolkunov (NATI) is to develop a uniform methodology and parameters for testing air filters from all tank factories (taking into account experience from factories ##75, 174, and 183) by February 13th, 1941.
People's Commissar of Medium Machinebuilding, V. Malyshev
People's Commissar of Heavy Machinebuilding, A. Yefremov"


  1. The T-34 tested in the USA at Aberdeen was cited as having a terrible air filter system. I wonder how long this problem persisted. The US verdict on the T-34 powerplant was essentially that it was an excellent design but the poor air filtration took a LOT of power away.

    1. As far as I know, an improved filter was only installed in 1943, while the Americans got an older tank.

    2. The Soviet report pointed out that the air filter in the T-34 was not used correctly during the evaluation. In any case, it was replaced with an improved model.

    3. The T34 sent to the US was from a special limited production run of five vehicles, made at UZTM (again, UZTM made the best T34 in this timeframe), and utilized only the best materials aviable. These were of higher quality than standart issue T34. Three were sent to the front, one to the US and Britain, respectively.

    4. Ah yes, the famous UZTM with the factory number 183, the one that
      wrote the number 5 suspiciously like 3

      Where do you get this nonsense from?

    5. It´s not nonsense it´s the result of actual research rather than hearsay.

      Boris Kavalerchik,Once Again About the T-34, in: Journal of Slavic Military Studies 28.1 (2015), pp.186-214.

      "On 3 June 1942 lieutenant-colonel Kozyrev, who was a military representative at the Ural Tank Factory (UTF) in Nizhny Tagil, received a written order from Moscow to prepare three T-34 tanks for shipment within a month.
      One of the tanks was going to be sent to the United States. The destination of the others had to be determined later (TsAMO D. 936, pp. 52–53). That the UTF was selected as the supplier was in no way by chance. At that time it was namely this factory that was producing T-34s with noticeably better quality than all other tank makers.
      The factory, of course, did not want to lose face before its allies and picked three of the best tanks out of those that successfully passed the acceptance test. They belonged to the latest production batch with all the changes and improvements made by that time. Particular attention was
      paid to their preparation for a future long journey. Vehicles were thoroughly cleaned inside and out, filled with fuel and fresh oil. To prevent corrosion they were coated with three layers of paint. Spots on the bottom portion where water could get into were protected with a thick layer of grease, and all hatches, holes, and chinks were thoroughly sealed. Gauze bags with desiccant were placed inside. Each of the three T-34s was furnished with
      detailed operating and maintenance instructions. They were added with separate manuals on the engine, armament, and the radio set, as well as a full set of assembly drawings, spare parts, and tool kits. At the end of August 1942 one of these T-34s, along with a KV heavy tank, was sent to the US. Another, also paired with a KV, was shipped to England from Arkhangelsk in June 1943, after a 10-month delay (TsAMO D. 1744, pp. 58, 64)."

    6. Given the amount of headaches the Soviets had with L-L tanks that had been sloppily prepped for the journey, and often turned out to be missing a variety of parts, equipement and important documentation, it is small wonder they were downright persnickety about such matters when sending stuff the other way...

      By the by, the order for that prep work is already in the article Peter linked. Not quite seeing what that part has to do with your argument anyway.

    7. Primary documents detailing the shipment = hearsay, sure, okay.

      Also, what is "TsAMO D"? Central Archives of the Ministry of Defense use three codes to specify a document (fond, opis, delo) instead of just one.

    8. Which brings us back to the article, which was about just the air filter.

    9. It does have a relevance. The Tomon air filters had a cleaning performance of only 79.6% for 1g/m^3 dust load. All the rest goes as abrasive into the cylinders. Such air filters would require maintenance every 2-3 hours in dusty conditions.
      The filters in the US sent samples were considered by the US as of criminally poor quality. That the air filters were not maintened properly is a thought which is belied by the fact that the soviets also sent an engeneerer with the tanks to the USAPG, whose responsibility was to teach the US personal the use and maintenance of the KV1 and T34.

      Cyclone air filters with 99% dust removal appeared in late 1942 (and not in all tanks), even though they also required short time maintenance in dusty conditions.
      Multi cylcone air filters with 100% capacity were not available until IS program and the T34/85 in 1944.

    10. The filter was called Pomon, not Tomon. The Soviets may have sent an engineer to help, but in correspondence relating to the tests the Soviets blatantly state two things:

      a) Components that are usually very robust were damaged in trials by the Americans.

      b) No technical assistance was requested from any Soviet engineers in the USA.

      So in these conditions it's quite likely that the filters were not maintained properly.

    11. Peter Samsonov. Perhaps the filter equipment was damaged during routine maintenance. It's easy to make mistakes when you are unfamiliar with foreign equipment. Plus the odds are the Soviets didn't us send complete maintenance books. In wartime these types of items are often neglected and those that exist are highly prized.

    12. The Americans should already have had all the documentation for some time though:

      "5. In July 1942, before the tanks were sent to the US, BTU GABTU KA sent blueprints, instructions, and manuals on the tanks, as well as lists of design changes made in 1942 compared to the tanks described in the manuals to comrade Krutikov, to give to US general Famoville.

      6. Since general Famonville wanted these items shipped by plane, they would have arrived in America before the tanks.
      Since then, we received no further requests for manuals of explanations."

      Doesn't mean some parts couldn't have been incorrectly translated or the US technicians for some reason not getting full copies or whatever ofc.

  2. I really doubt Russia would send their best to America. In the back of their minds we were still the enemy.