Peter Samsonov is a Russian-Canadian military historian with a focus on Second World War-era armoured warfare. In addition to running the renowned Tank Archives blog, he writes articles for various online and print publications based on English, Russian and German language primary documents.
Peter Samsonov
First published in Great Britain in 2021 by Gallantry Books
an imprint of Mortons Books Ltd. Media Centre Morton Way Horncastle LN9 6JR www.mortonsbooks.co.uk
Copyright © Gallantry Books, 2021
All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical including photocopying, recording, or any information storage retrieval system without prior permission in writing from the publisher.
ISBN 978-1-911658-47-4
The right of Peter Samsonov to be identified as the author of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988.
Typeset by Burda Druck India Pvt. Ltd. Printed and bound in Great Britain by The Magazine Printing Company
I would like to thank Yuri Pasholok, Pavel Borovikov, Dmitriy Ukryukov, and Yevgeniy Profiryev for their contribution of photographs and documents that made this book possible, as well as H. G. W. Davie for help with making the maps. I would also like to thank Maryse Beuregard for proofreading the finished work.
In 1954, the Soviet Ministry of Defence published a book on tank technology aimed at the general public, describing the history of tank design and the operation of various components and assemblies used by tanks at the time. Only a handful out of more than 600 pages are dedicated to foreign tank development during the Second World War. Although the text describes the Medium Tank M4 as the most common American tank of the war, there are few specifics. Not even a photograph of this vehicle is included.
This brevity was not out of a lack of information. More than 4000 M4A2 tanks and two M4A4 tanks were shipped to the Soviet Union during the war. Thousands of pages of documents with impressions from the specialists who tested the tanks, crews who fought in them, and commanders who directed them in battle were written – only to be buried in the ideological battle of the Cold War. More than half a century later, the popular history of the Sherman tank in service with the Red Army is based largely on memoirs, rumours, and guesswork. This book will attempt to give the reader a glimpse through the decades-long information barrier at the experience of Soviet crews recorded in the moment, untarnished by political pressure and uneroded by time.
The United States had few modern tanks when war broke out in Europe on September 1, 1939. News from the front lines revealed that the Germans fielded a medium tank with a 75mm cannon. Despite the limited information at hand, the army decided that its newest tank, the Medium Tank M2, was no match for the new German tank. Since it was only a matter of time before the US was pulled into the war, a new American tank had to be developed
that could defeat it. The work put into the Medium Tank M2 served as a foundation for a new medium tank that could be competitive in the current war.
The United States already had a candidate for the gun. The T6 was a promising AA gun developed from the 75mm M1897 field gun and had the semiautomatic breech that a tank gun required. It was developed into the T7 tank gun. Since no turret large enough to accommodate such a gun was available, the 75mm gun was installed in a sponson mount. This concept was previously tested in the Medium Tank T5E2, an earlier experimental tank. Due to the rush, the new medium tank was accepted into service as the Medium Tank M3 on July 11, 1940, before the first
example had even been presented. The army was not thrilled about the vehicle’s unconventional layout, but it was regarded as sufficient for a temporary solution.1
Characteristics of a tank that would have its main gun in a turret were drawn up on August 31, 1940. Engineers began working on this new tank on February 1, 1941, as soon as the design of the Medium Tank M3 was finished. This design was approved on April 18, 1941. For the sake of expediency, the lower hull, engine, drivetrain and suspension would be taken from the M3. As many components as possible were reused to speed up the design and development process. The 69in turret ring specified gave the tank a number of options for armament:
the same 75mm M2 gun used in the Medium Tank M3, a 105mm howitzer, two 37mm M6 guns, a British 57mm 6-pounder, or three .50 calibre machine guns. All options but the last included a .30 calibre coaxial machine gun. The first option was selected as this gun had already proven itself in the Medium Tank M3.
Some historians interpret the consideration of a British gun as evidence that the Canadian Ram tank, also based on the M3 chassis, influenced the design of the new American tank. This is unlikely: the Ram tank arrived at the Aberdeen Proving Grounds in July, by which time the choice of armament was already made. Additionally, the Canadian tank that arrived at Aberdeen
ABOVE: A complete GM 6046 engine at the Musée des Blindés in Saumur, France. Each half has its own set of accessories, including two air filters. Issues with the filters were common in early M4A2 tanks.
ABOVE: A cutaway tank showing the layout of the GM 6046 engine and its accessories in an M4A2(76)W HVSS tank. Canadian War Museum, Ottawa, Canada. The engine fitted perfectly into the existing compartment without any need to enlarge the tank’s hull.
carried a 2-pounder gun, which was never considered as an option by the Americans.2
A wooden model of the new tank was built in May of 1941. After inspection of the model, approval was given for the assembly of two prototypes: a tank with a welded hull built at Rock Island Arsenal and a tank with a cast hull built at the Aberdeen Proving Grounds. On September 5 the Ordnance Committee recommended the standardization of these two tanks as the Medium Tank M4 and M4A1 respectively. Production of the M4A1 began in February 1942; production of the M4 began in July. There was only one small problem: Continental Motors could not keep up with the demand for R-975 engines to satisfy the needs of the American tank industry so a new source of engines
was needed. Thankfully, the Americans had plenty of alternatives.
A General Motors 6-71 two-stroke diesel engine was first tested in the light tank M2A2E2 on February 2, 1939. Other nations also specified GM’s engines for tank production. A Valentine tank with a GM 6-71 engine was sent to Canada in the autumn of 1940 and became the template for production of the Valentine VI and VII tanks. 3 By the end of October 1941, GM’s diesel engine division had expanded its capacity to 1000 diesel engines per month.
These engines were a tempting option to solve the Medium Tank M4’s engine shortage, but some work had to be done in order to make them suitable for the task. For one, the M4 was quite a bit heavier than
