Monday 9 March 2020

Grosstraktor Amphibious Trials

"People's Commissar of Military and Naval Affairs
Chairman of the Revolutionary Military Council
K. Voroshilov
November 3rd, 1929
Moscow, 19 Frunze St.

To: Comrade Stalin

I attach a report on testing the amphibious properties of German tanks at Kazan. The experiments have been unsuccessful so far. Recall that although the tanks are early prototypes, the Germans spent 6-7 years on designing and building them."

"October 30th. Our friends were testing the Rheinmetall tank's swimming. It was scheduled at 13:00, but our friends began earlier, at 12:00, which I found out by sheer accident. Perhaps our friends wanted to conduct the first trials without us to later show us a prepared procedure. Personally, I was with the tank when it went towards the lake at 12:00. The rest came at 13:00.

The first swim was successful to a distance of 5-10 meters. The tank was connected to a tractor with a cable, but this was unnecessary. On the second swim the cable was removed and the tank went in without any safeties. The tank was submerged in water by 3/4 and floated, after which it took a right turn. When the tank turned it tilted, and water entered the engine compartment, then the turret compartment, then the whole tank. An attempt by our friends to reverse failed, as the tank quickly submerged and sank.

The tank was driven by engineer Engel and mechanic Kerres. Two of our metalworkers were in the tank, and engineer Merz was sitting on the turret. When the tank started sinking engineer Merz jumped into the water, and soon engineer Engel and our metalworkers emerged from the water. Mechanic Kerres remained in the rear compartment and died.

I took immediate measures to save mechanic Kerres. A diver was summoned through OGPU chief comrade Kandybin, but he arrived too late. It was not possible to tow the tank out, as it had submerged to 3-4 meters. The weather was rainy and the wind was strong.

Our cadets took an active part in the rescue of our friends and comrades. Comrade Kashuba showed himself especially well. He remained composed when his boat flipped over during the rescue, letting the others hold onto the boat until a second boat arrived and picked them up. Comrade Kashuba swam away himself. The cadets were not participating in this work but were only witnesses, aside from Mr. Nipman, who drove to the grounds and back.

I can't avoid stating that the trials were disorganized and there were no safety measures taken. It seems that our friends were confident in their calculations and the amphibious ability of the tank, but maybe they just did not have the necessary experience. Our friends did not consult me in this matter and did not ask my opinion. I told Mr. Pirner many times that they may drown with the tank, he just smiled and replied "We'll see". 

I must state that this catastrophe would not have taken place if our friends had conducted organized trials and taken precautions.

I will send additional details of these two events by mail. Today (October 31st) the recovery of the tank will take place. All preliminary work has been done and a diver is present.

Our friends' disposition in connection with what has happened is bleak. Work is being done without enthusiasm."


  1. Hello! Do you have any plans to make more detailed articles about Grosstraktor? Those about L.Tr. they are very good. I'm looking for information about Grosstraktor but I can't find it!

    1. I have this article:

      There are no plans for any others currently.