Wednesday 25 September 2019

Gotta Go Fast

"To the Chief of the Rear and Supply Directorate of the General Staff, Major General comrade Yermolin

According to your order, I present to you the conclusions on the draft project of a tank glider developed by TsAGI engineers including comrade Yermonskiy.

The project proposes a 6 ton tank that can be towed behind an airplane as a glider. The tank accelerates on its tracks with the tank's engine power to at least 100 kph.

The proposal has the following issues:
  • No tank presently exists that weighs 6 tons and can reach a speed of 100 kph.
  • The creation of a tank weighing 6 tons with armament and armour that meets modern requirements is a big issue.
Because of this, the realization of this project would not be sensible.

In addition, I report that factory #81 is working on air transport of military materiel, including a T-40 tank, using high capacity cargo aircraft. All necessary information about the vehicles and armour was sent to the GABTU.

I consider the work performed by factory #81 to be more reasonable and capable of replacing this proposal.

Deputy Chief of the GABTU, Major General of the Technical Forces, Lebedev
July 15th, 1941"


  1. When we see Hollywood movies of cars being backed out of tractor trailers they usually drive much slower. And it's a lot easier to guarantee the trailer is driving straight at a specific speed than it is for a glider to come down level at a specific speed when it its the ground.

    1. I've read the article several times now and still cannot see how the above connects with it at all.

    2. When a vehicle impacts the road on the move there are so many things that can go wrong. In Hollywood stunts they work hard to control everything and make sure each wheel hits the road evenly. A glider carrying a tank is not controlled. If one side hits the ground and the glider was not at the pre planned speed, the tank will twist and flip over. This is why we use sleds with parachutes.

    3. Unless I'm somehow managing to read it entirely wrong this isn't about a tank being transported *in* a glider (which is entirely doable anyway; see the Tetrarch for ex) but *as* one, though. This sounds like a proposal in the line of research that eventually produced the A-40 glider frame for the T-60 (which apparently actually worked pretty well but there wasn't a sufficiently powerful plane to tow it); the Japanese and British also looked into similar ideas.

    4. It describes a tank being lowered behind a plane in effect a towed glider. Hence the reason the tanks tracks needed to be running at 100kph when the tank hit the ground. Ideas like this and flying tanks were common in the 1930s.

    5. It's talking about *accelerating* the tank though, which sure sounds like takeoff phase to me. Also not actually necessary in the first place and indeed one of the Japanese experimental projects just ended up strapping skis to the tracks because those couldn't survive the takeoff by themselves so, yeah. Not really sure what the good comrade Yermonskiy & Co. had been drinking.

      As far as landings go the Soviets apparently successfully experimented with low-speed ultra-low-altitude tank drops right off the bottom of the fuselage in '40 and the cans obediently rolled to a halt on neutral. 100 kph on engine power would be not only even more unnecessary at that stage of the operation but outright counterproductive because, well, you want the tank to *stop* ASAP before it runs into a bad batch of terrain or an obstacle of whatever kind...
      Not unlike why planes brake as hard as they can get away with on landing.

    6. In this case you have a point. Bear in mind we are literally talking about a tank glider which has enough lift to take off at the slow speed of 100kph. And yes landing in neutral would make more since. But much depends on the tank glider landing on a smooth surface and flat. Something gliders have little control over. Otherwise the tank would bounce around like all the crashed cars from failed jumping stunts from the TV show Dukes of Hazard.

    7. Tolerably sure the intent was merely to use the speed of the tank itself to assist in the towed takeoff... which, as already mentioned, isn't even necessary in the first place so the whole proposal seems rather perplexing.

      As far as desirability of clear LZ goes, well, that goes for *anything* aerial that isn't landing entirely vertically and even those tend to prefer coming down to a plot as flat and smooth as possible for obvious enough reasons. Rommel had the fields in Normandy staked for a reason - not that it stopped the Allied paras and gliders anyway.