Chapter Two
There were 15,153 75mm armed Sherman tanks alone, supplied to Britain by the end of 1944. The Sherman tank was one of the first armoured vehicles to be mass produced anywhere, and was designed over a relatively quick period due to urgent demand for armour of its type at the front in early war years. This demand simply originated from disastrous inter-war planning. American Industry had no experience of mass producing armoured tanks, and was also recovering from having survived the Depression just a decade earlier. America’s isolationist stance contributed nothing to the urgency of re-equipping a modernized army for World War. The inter-war tank designers and military planners had failed to examine the three primary design features of firepower versus protection versus manoeuvrability in real depth and to settle on their armoured warfare doctrine in any great detail. American planners could not decide whether tanks would be fighting other tanks on the battlefields in a future war, or supporting foot soldiers. In Britain the inter-war tank designers had also been struggling with the new concept of fluid mobile armoured warfare. Should the tank fulfil a support role for the infantry, or should it become an instrument dealing the striking blow that secures the battlefront victory? Any visit to The Tank Museum at Bovington will demonstrate how confused British designers were in conceiving a worthwhile armoured fighting vehicle during the 1930s, especially after the Director of Mechanization in the UK ordered all development work to stop on a replacement for a British Medium Tank. Every experimental shape and size is exhibited, but not a single one that actually promised reliable results. Some experimental types bristle with inadequate light machine guns, some have small calibre main guns with limited traverse and elevation located in Flash Gordon inspired sponsons – laughable almost and disastrous!
Something that was so right by comparison however was a concept which began life in the USA during 1940 with the request to mount the proven US 75mm M3 Gun in a new turret, mounted on top of a fast armoured vehicle to fulfil a medium tank role. The first Shermans were in full production by late 1941. The Sherman was an unsophisticated piece of machinery making it easy to repair, cheap and quick to produce, but rugged due to the solid materials used in its construction. Its reliable chassis unit went on to provide the foundation for a huge range of specialized adaptations as well as its proven success as a turret tank. Main strengths stemmed from its simple construction which produced the conditions for it being simple to operate. Conscription of new citizen soldiers such as rural farm labour, factory and railroad workers meant that a proportion of this diverse range of men found themselves at tank schools wearing the uniform of the Armoured Division trooper here and in the US. The Axis advances across the world by 1942 ruled out years of expensive and professional training. Crews and tanks were needed instantly. Once round an open field and the trainee Sherman driver would have a basic grasp of the driving controls before further instruction continued. The crew tasks carried out at each station of the Sherman were designed with simple manual actions in mind, not only were the individual tasks straightforward, but the ability to learn the other crew members’ responsibilities was thus possible, and often sensibly adopted in action in case of death or injury on the battlefield. Road wheels could be changed manually by the crew, and the track could also be removed for repair by the crew as illustrated in the Far East chapter of this book. When one considers Tiger or Panther track in size and weight comparison only heavy lifting equipment could assist the larger German armour in instances of repairing the running gear in the field.
The drawbacks from its urgent inception were also numerous and no historian denies the Sherman design arrived inclusive of many faults and weaknesses. Not least the thin armour chosen due to planning that the tank would be shipped overseas therefore weight reduction was a factor. Most overseas ports only had cranes capable of lifting a maximum load of forty tons, therefore a design of anything larger was deemed pointless. Inter-war doctrine added to the confusion, for the role of the Sherman was never clearly defined during its development. It was never envisaged in a tank against tank role initially, and therefore armour protection was listed as a lower priority. The mounting of large fuel tanks alongside the rear engine compartment, causing any escape of fuel from battle damage or loose connections on the hot engine to guarantee an inferno within seconds was also a flaw, as was its high silhouette due to the fitting of bulky radial engines. Thinner armour than German counterparts facilitated speed from a range of diesel and petrol powered engines, but at the cost of crew and ammunition protection. Production lines continued to complete tank after tank in their thousands, as more manufacturers became involved in component provision for Sherman production. Swathes of farmland on the outskirts of Detroit, Michigan were turned into huge production facilities under the auspices of Chrysler Corporation Head, K T Keller, as it was in other mid-western states.
The facility in Michigan became known as The Detroit Tank Arsenal and it was this capacity for production that made the Sherman the right tool for contribution toward victory. High production figures imbued the tank with ultimate attritional battlefield power. During Operation GOODWOOD in Normandy some uninjured crews who lost their armour in action were able to walk back to the rear area and collect another tank to proceed with the advance. At the close of the operation some 450 tanks in British service had been lost, but the Allied Force was re-equipped and continued onward. German armour losses at the closing of the Falaise pocket by comparison were simply irreplaceable. By mid-war the Sherman was fighting on all fronts for the Allied cause. This book features locations from Mandalay to Munich. M4 variants continued to evolve with new suspension units, track design, new turret castings, larger main guns and experimental additional armour plating throughout the war years and with the many armies it has served with since the Second World War.
Returning to pre-war 1938 we should consider briefly the design and development phases, and the gearing up of American industrial might toward the mass production of the famous Sherman turret tank models illustrated in this book. A feature of production methods in wartime was the inclusion, re-use or adaptation of as many existing parts from other vehicles into new designs as was possible. One reason for this was the influx of women into the factories who had no technical apprenticeship training, and individual tasks were thus de-skilled generally and reduced to simplest form. Many women were trained to perform highly skilled engineering work, but to integrate the large numbers of new staff into the factories a gradual programme was devised beginning with de-skilling. If an already proven component off the shelf could be utilised, this cut manufacturing time even further. The realisation on both sides of the Atlantic that a world war was inevitable in the late 1930s enforced rapid preparation. The US Army had already acknowledged the worth of the M3 Light Tank which had been accepted into service in armoured reconnaissance roles but they still required a stronger version, a Medium tank.
The Rock Island Arsenal worked up a new model known as the T5 (Phase 1 design) in 1938 which used many of the M3 Light Tank’s already available parts including its 37mm main gun. It also featured Vertical Volute Suspension (VVS) and a Continental Radial air-cooled engine producing 250 BHP. The design of the T5 allowed for a barbette and turret, the 37mm main gun housed in the turret, and four .30 Browning machine guns mounted singly into sponsons on each corner of the barbette. Additionally another two .30 Brownings protruded from a fixed position mounting in the hull front. The Rock Island Arsenal had definitely hit upon the basics for a good medium tank, but not in its current incarnation. The T5 was developed through several further phases that year, including test use of wider tracks, and a larger power plant. Its overall weight, thus strength, was increased until it metamorphasized into the Medium tank, M2 of 1939. Clearly a development on from the T5 tank, the M2 owed much to the lighter M3 Light tanks including its main armament of the standard 37mm gun. A finalized version called the Medium tank M2A1 with redesigned turret was adopted in 1940 and was deemed to be the new standardized medium tank for the US Army. Despite ongoing debate about the role for the new M2A1 the reality was that it was immediately obsolete. It had been known for a year or two previous that the German armoured forces were having 7.5cm (75mm) main guns fitted into their tanks. Largely ignoring this information, the US Army continued to rely on the 37mm gun as the main weapon of newly designed medium tanks intended to command the battlefield.
Rearmament and war-preparation issues came to a head in August 1940. News from France was both grim, and indeed of major concern for US Army planners. The 75mm German gun was ruling the battlefield in the German accelerated drive through Belgium, Holland and France during the charge for the coastline. Their advance across hundreds of miles was being measured in days and weeks and not in the months or years of The First World War. Decisions were needed urgently. The Chief of the newly formed Armoured Forces, US Army and planners from the Ordnance Department worked hard to formulate specifications for an improved medium tank capable of opposing German armour. The test results from the experimental T5 Tank development and the resulting M2 and M2A1’s would prove most helpful in this planning. Specifications were soon drawn up: another new tank, but it required much thicker armour, needed to be fast, needed a bigger gun – the 75mm, and this gun needed excellent traverse and elevation ability – it simply could not be restricted in a sponson, mounted into a turret on top of the tank with full 360 degree rotation. However, on examining the experimental work carried out in the two years prior they immediately ran into a problem. Little to no development work had concentrated on mounting the heavier 75mm gun in a turret – most work had concentrated on increasing sponson armaments, the power from engines, and mounting of more machine guns or improving track strength.
The experiments that had been recorded involved mounting a 75mm Pack Howitzer into a prototype T5E2 medium tank (The T5 phase III of experimentation from 1938), but results only existed where the howitzer had been mounted in a modified sponson on the right side of the front of the tank. Urgency created by the advances in Europe dictated that it was these experimental efforts that must be further concentrated upon. There was no time to begin designing a turret from scratch to house the 75. Redesign occurred rapidly and the result was the M3 Medium Tank. It now weighed 31 tons, was armed with a 75mm M3 Main Gun in the sponson, and retained a 37mm M6 gun and .30 machine gun in a turret on top of the vehicle. Additional .30 machine guns were mounted in the hull front and also on the turret cupola. See IWM H 20919 which illustrates one of the first M3 Lee tanks to arrive in the UK. The pilot model M3 was ready in January of 1941 and the standardized production models reached troops toward the middle of 1941. Many were supplied both to Russia and to Britain as H20919 demonstrates.
Companies such as the Baldwin Locomotive Works, Pullman Standard Car Company, Lima Loco Works and The Pressed Steel Car Company all had British government contracts for the M3 Tank. British Tank Commission contracts asked for some slight alterations and the resulting production models were know as Grant Tanks. In Canada armoured forces were also looking to bulk up their strength with new armour so the Canadian government contracted with the Montreal Locomotive Works Division, part of The American Locomotive Corporation for the construction of some 1,157 tanks based on the M3 design also. It was the first Medium American tank to see action in the 1939-45 war both in Russia and Libya and feedback from crews was countenanced. Important standards were certainly set with the M3 such as the power-traversed turrets and gyrostabilizers for the guns which appeared again in the later Shermans. However, the feedback was not all positive. British Armoured Forces using Grants were in violent action at Gazala in Libya during May of 1942. Troops found that US planners back in August of 1940 had been absolutely correct in identifying the sponson mounted 75mm as a weakness. British crews found the limited traverse and elevation of the 75mm gun of the M3 and M3A1 Lee variants a huge disadvantage, often driving their vehicles toward their target in order to achieve a line of fire. The high silhouette overall of the tank in flat desert surroundings created a suicidal armoured vehicle to be caught in the open with. The gun was powerful however, and vastly improved up the 37mm still fitted in the turret, and there was relief that firepower disadvantage was at least diminishing.
Changes were incorporated into the design as stop gap measures more than serious attempts to placate crews. The original design of the M3 series had a riveted hull and used a Continental Wright R-975-EC2 or R-975 Petrol power plant. The M3A1 used a new cast hull in the hope of providing stronger protection for the crew and eliminating weak points where armour plate had been riveted together on the M3. The M3A2 was similar again but used a welded hull manufactured from individually cut armour plate and welded together. The M3A3 used a new power source in the form of the Twin General Motors 6-71 Diesel Engines in a bid to limit fuel combustion due to battle damage. The M3A4 utilised the original riveted hull but with the Chrysler Multibank engine which would also turn up in the later M4A4 Sherman and finally the M3A5 variant paired the riveted hull format with the Twin 6-71 diesel motors. Which ever way round the Lee/Grant tank was produced, it was fundamentally flawed and the crews did not like them. If given the choice they hoped for a better designed tank. Privately, they did not want to work in them, they did not want to drive them, and did not want to get involved in a skirmish on the battlefield against Axis armour inside one despite the fact they now had a main gun which could take on the opposition and which at least boosted morale after previous experience with the outdated 2 and 6-pounders of earlier British Tanks.
Some design work had commenced in 1940 experimenting with mounting the 75mm gun in a turret with 360 degree rotation. It would have to be mounted on a tank which used as many M3 tank parts as possible as this was already in production: road wheels, suspension, track, engines. The result of this work materialized on 16 September 1941 in the form of the Medium Tank T6. A cast hull and turret built around a short barrelled 75mm gun. The gun had two large muzzle weights fixed around the end of the barrel used to simulate the full mass of a larger gun when being tested, the 75mm M3 Gun which was used in final production models. There were two fixed Browning machine guns in the front hull, plus another which could be rotated in its ball mount also in the hull. Vertical volute suspension was used from the M3 Lee tank, with track return rollers mounted at the top centre of each bogie. These fittings can be noted on Michael in photograph IWM KID 1234. With further development the T6 became the standardized medium M4 Tank in October of 1941. By early 1942 it was in full production as the M4 and was being shipped to all campaign theatres. It was first tested in combat with the British Eighth Army in October that year during the battles of El Alamein, considered so secret a weapon at the time troops were instructed to refer to is by its codename THE SWALLOW. Later combat road testing took place in the TORCH landings by US forces in Algeria. The M4 vastly improved upon the M3 Medium tank design and consequently was used to replace the obsolete M3. Crew feedback was again consulted. With a much lower silhouette, a crew position eliminated and an assistant driver catered for plus the bigger gun and faster cross country ability the Sherman tank was adopted for the duration by all Allied armoured units. The following chapters reveal how the Sherman tank in its many variant forms contributed to Allied victory on all fronts. You will view some of the 49,000 or so Sherman tanks produced during the Second World War in the chapters included in this book.