Objective of the trip: familiarize the commanders of the Military Foreign Vehicles Approval unit, repair base #97, 16th UTP, and 92nd Tank Brigade for American methods of tank use and repair, as well as assistance in learning how to operate the new M4A2 tank.
American representatives: Lieutenant-Colonel Grey, Ford, Thornton, Aikanymeaux. After Lieutenant-Colonel Grey left on January 6th, Major Olson arrived to serve as the military representative.
Time spent: December 11th, 1942 to February 2nd, 1943
Supplies for the Americans: The Americans spent the first two weeks in hotel rooms at "Tourist". Because of this, breakfast and dinner was eaten at the hotel, and lunch was eaten in restaurants in the vicinity of the automotive factory. Since subsequent work was performed at the automotive factory, the visitors were moved to the "GAZ" hotel, and all meals were eaten at the aforementioned restaurant.
A ZiS car was issued by the Gorkiy Armoured Vehicle Center to service the Americans.
There was one trip to the Opera theatre to see The Barber of Siberia. A trip was taken to the 16th Tank Training Regiment lounge by invitation of the commander, Colonel Rubinov, where we watched "Regional Committee Secretary" and "Three Musketeers". There was also an amateur concert organized by the 16th Regiment for the Americans.
The Americans read Soviet newspapers. They were aware that there was a donation drive for the construction of an air squadron named "Vasiliy Chkalov", to which the Americans donated 1900 roubles, handed in to the finance chief of Repair Base #97.
The Americans gave lectures on the components, electrical equipment, radio, and armament of the M3 and M4A2 at the Vehicle Approval department. The entire American delegation was involved with lectures. The organization was exemplary. The same lectures were given to the 16th TTR, but without Lieutenant-Colonel Grey.
Before they left for Dzerzhinsk, Lieutenant-Colonel Grey and Mr. Ford taught classes on the components of a M4A2 for the 92nd TBr's officers. Grey and Ford inspected broken M4A2 tanks and gave directions to remedy their defects. Some of the tanks were later sent to Repair Base #97.
Most of the work was done at Repair Base #97. The commanders and tank repair technicians were familiarized with repairs of the M4A2 tank, and engines "Wright" and "Continental". The Americans took an active role in repairing M4A2 tanks and American supplied engines, during which they explained some specifics about repairing the engines.
Mr. Ford also helped with a broken Valentine tank engine.
Two M4A2 tanks with S-injectors were tested, and replacement of M-injectors with B-injectors was investigated.
Transmission repairs with removal of bogeys was organized, for which a cart with 4 jacks and 4 wheels was used. Using this cart, it is not difficult to perform repairs. (I have the blueprints for this cart).
In the radio laboratory, Mr. Aikanymeaux helped our specialists repair radios. Experiments were performed to determine the ability of English and American radios to communicate with each other. (Engineer-Major Artunyats has the results).
The Americans were shown construction of new vehicle repair workshops, on which they made comments and gave suggestions. Afterwards, Lieutenant-Colonel Grey promised to send equipment and special tools for workshops.
When a passenger airplane had to make an emergency stop in Gorkiy, Major Olson and English Colonel Hugo, accompanied by an NKVD captain, arrived at the automotive factory hotel. The aforementioned foreigners had a meeting with Lieutenant-Colonel Grey, where Grey learned that there are a lot of American instruments lying around unsupervised in Basra.
4 days after Olson and Hugo left, General Faymonville ordered Lieutenant-Colonel Grey to leave for Moscow, allegedly to go to Basra to get the instruments. However, three days before his departure, Grey had a call with Faymonville, which was very unpleasant, as Grey was in a very bad mood afterwards. To my inquiries, he replied that Moscow is full of lazy people (Bundangles). [The translator did not know the word and wrote it in English in the document, perhaps Grey used the term "boondoggles"] In deep thought, he repeated "I don't know what they want from me. What's the matter?". Presumably, General Faymonville made an excessively honest complaint, as Lieutenant-Colonel Grey repeatedly sent him letters and telegrams demanding that the quality of shipments be increased, making a note of how difficult it was to service tanks without instruments and the poor quality of injectors.
Soon after Mr. Grey left, another military representative of the Mission arrived, Major Olson, who was not a tanker. While we were present at Gorkiy, three clerks came to the American representatives with books and supplies. Captain Cross also made a visit.
While Mr. Ford was sick, Captail Woldrun came to visit him in the hospital (where Mr. Ford had a dedicated room), and took part in the commission to cure his illness, headed by Military Doctor 1st Grade, Professor Rybakov. After 10 days, Mr. Ford made a good recovery. His illness was a digestive one, which he acquired while still in America.
When the commission was working, Captain Woldrun made few comments, which Professor Rybakov attributed to his poor knowledge of medicine.
I maintained communications with regional UNKVD (comrade Davydov), regarding arrivals and departures of the Americans, and their communications. Lieutenant-Colonel Grey sent two encrypted telegrams to Moscow, which were delivered by a courier, due to a lack of English encryption machines.
On the issues with M4A2 tanks, the following is known:
M4A2 American tanks that arrived in the USSR have a series of defects, discovered when they arrived at Gorkiy. A partial list of defects is as follows:
- Twin GMC 6046 engines are augmented GMC 6004 engines, from 165 hp to 225 hp. The increase in power is achieved by increasing the fuel supply and increasing the average effective pressure by 27%. In order to achieve this, the S-injectors have the following changes:
[tedious technical details]
However, the aforementioned changes do not guarantee reliable operation of M-injectors. For instance, out of 26 tanks that arrived, 11 had scorched injector nozzles.
Trials of the M4A2 tank with S-injectors showed that it is possible to use S-injectors in the event of M-injectors breaking down, but the tank's power is reduced. There are very few spare M-injectors.
The same trials showed that the spherical holders for injectors, as well as spare holders are not ground down, which significantly impacts the fuel injection.
- There are many cases where cylinder casings are torn off, pistons are destroyed, and fragments of pistons penetrate the cylinder heads. This is caused by the following:
- Uneven heat distribution on the surface of the piston, due to the fact that the injector does not distribute fuel evenly, but in streams. The edges of the piston are melted in the direction of the streams.
- Insufficient cooling of the piston. The engine's temperature is increased, but the piston cooling was not changed. Heat is dissipated by spraying oil from the top nozzle in the same amounts as on the 6004 engine. Due to insufficient cooling, fouling collects in the spaces between rings, making it difficult for the piston to work, and increasing the odds of it scorching.
The fouling makes lubrication difficult, increases friction between the piston and its casing, the casing overheats, deforms, the piston jams, and the casing is torn off.
It is necessary to inform the Americans of the necessity of improving piston cooling, if only by increasing the amount of sprayed oil.
- It is difficult to fill up the cooling system, and takes up to 2 hours, which is why the system is being modernized. In order to process one tank it takes 40 man-hours. It is desirable for the tanks to be shipped with a modernized cooling system.
- It is difficult to start the engine due to the difficulty the pump has getting fuel from the tanks, especially after prolonged periods spent parked, when there is no fuel between the pump and fuel tanks. There should be a manual pump to create pressure in the fuel tanks so fuel can be supplied to the pump before starting the engine.
- The friction clutch often breaks for the following reasons:
- The friction clutch slips due to desynchronized work of the engines.
- The friction clutch on this tank is weaker than that of the Valentine with a GMC engine. The Americans themselves admit that it should be strengthened.
- The engine RPM synchronizer with the "hand gas" lever is difficult and imprecise, giving a variance of up to 200 RPM, which wears out the friction clutches quickly. The issue of synchronization should be reworked, at least by replacing the "hand gas" lever system with a screw system.
- Some M4A2 tanks have a new suspension system, where the return roller is moved to the side, which prevents its jamming with snow or mud. This modification has proven itself as superior, and should be adopted on all tanks.
- M4A2 tanks are shipped without antifreeze, which complicates use during the winter.
- Americans cover the secondary fuel filters with an anti-corrosive substance, which should be removed in order to not damage the injectors.