The M4 Sherman

The Sherman, officially "Medium Tank, M4," is the single most iconic American tank of World War II – and arguably ever. It is a symbol of American industrial might, and it was designed from the get-go to take advantage of the nation's massive industrial capacity. While not the most powerful tank individually, it could be built in massive numbers; its dimensions allowed it to be transported across the country by rail and to be crammed into transport ships the most effectively. Though a famous vehicle, it is still surrounded by false myths today. Was it the best tank of the war? It wasn't. Was it useless because it couldn't defeat the German Tiger tank? It wasn't, and it could – under the right circumstances. Could it easily defeat the Tiger? It couldn't. Did its gasoline fuel tank make it a death trap for the crew? Not at all. Today's newsletter is about the Sherman, and hopes to dispel some of the myths surrounding it.

America needed a new medium tank by the spring of 1940. The previous design, the M2 Medium Tank was getting obsolete (and there were only 112 of them, anyway). Additionally, Great Britain was fighting a desperate battle against the Axis powers alone after the fall of France, and needed help – quickly. American engineers came up with the best design they could at a short notice: the Medium Tank, M3, better known by its British names of Lee and Grant (the U.S. and British patterns, respectively).

The M3, however, was cooked up in a hurry and was really only good as a stopgap measure. It had good armor and firepower for its time, but it was a tall and large target, it had poor off-road performance, various design problems, and its sponson-mounted main gun had a limited field of fire. It was clear from the beginning that an even newer tank was needed, one that got things right. Design of the new tank came hot on the wheels of the M3, and it was approved in April 1941. This design became the Medium Tank, M4, better known as the Sherman. It incorporated many lessons from America's light tanks in the '30s, and was planned as a fast and dependable tank which could be used to support infantry, break through enemy lines, and shore up defenses as needed. It should be noted that while American tank doctrine at the time expected the tank to be effective against a wide range of enemies, including other tanks, there was still little emphasis on tank-to-tank action. Tellingly, the 142-page U.S. Army field manual on the use of the Sherman only dedicated a single page of text and 4 diagrams to tank-to-tank combat. This was because American doctrine also made provisions for dedicated tank destroyers, and they were the ones expected to stop attacks by massed enemy tanks.

Shermans first saw combat in North Africa, during the Second Battle of El Alamein, in late 1942. These Lend-Lease tanks manned by British crews acquitted themselves well against German Panzer III and IV tanks. The tank rapidly acquired a good reputation, and President Roosevelt intended to have 120,000 of them built. In the end, only slightly less than 50,000 Shermans were produced, as the Navy also had a tremendous hunger for steel for its warships; but even that makes the Sherman the third most highly-produced tank in history. The U.S. Army ended up fielding 16 tank divisions in the war, while the Marines, who had less of a need during their island-hoping campaign in the Pacific, made do with six. One note of interest about Marine-operated Shermans is about their use of the floor hatch. If you've seen the movie Fury, you're familiar with the hatch in the Sherman's floor. This was normally used to dump spent shell casings and to escape the vehicle in a hurry. The Marines found a new use for the hatch: if a wounded infantryman was under fire, they would drive above him and pull him up into the tank through the hatch for evacuation.

The Sherman came in numerous versions over the war. We're not going to go through all of them in detail, but one important note about the official designations is that they did not imply or represent a linear improvement. An M4A2, for example, was not necessarily better than an M4A1, nor was it necessarily produced later in the war. The different numbers simply meant different production variations, usually meaning that they were assembled in different plants. There would often be numerous differences between roughly concurrent designs (such as different engines and various small changes), but only a few specific designations meant a large leap forward. One such important improvement was the M4A3E8, the famous Easy Eight introduced in 1944. Featuring a better suspension system then previous models, thicker armor, a more powerful gun and safer ammunition stowage (see more on these later), it was, and remains, the "definitive" version of the Sherman for many.

One notable weakness of the Sherman was its 75 mm gun. As mentioned above, this gun served well against Panzer IIIs and IVs in 1942, but the armor-piercing shells made for it just couldn't reliably deal with Germany's newer Panther medium tank and the heavily armored Tiger. The Sherman's gun had no real chance of penetrating the frontal armor of a Tiger from 1000 meters (1094 yds) away, while the Tiger could easily take out a Sherman at that range.
 
The Ordnance Department had been working on a 76 mm gun with better armor-piercing capability since 1942, but there was a great deal of institutional resistance. As mentioned before, tanks were supposed to engage a variety of targets, with an emphasis on enemy infantry, fortifications and bunkers – targets which require high explosive (HE) shells. And tests with the 76 mm gun suggested that the HE ammunition designed for it was just not good. A test was conducted in which HE rounds were fired from a 75 mm gun, a 76 mm one and a 105 mm howitzer (which was mounted on many Shermans for use against infantry, unarmored vehicles and fortifications), then men counted the pieces of shrapnel that lay on the ground within 20 feet of the targets. The 76 mm HE round came last, with 560 bits of metal as opposed to 950 for the older 75 mm gun and 1,010 for the howitzer. This led many people to conclude that the new 76 mm gun's HE rounds were not lethal enough.

Additionally, many battlefield commanders were of the mind that if the Sherman with its 75 mm gun can't take out a group of German tanks, they can just call-in dedicated tank destroyers. In actual practice in Normandy, however, tank destroyers were often pressed into front-line service as general gun platforms, and were often not available where and when tank units needed their help.
One thing the Shermans could do in the face of German heavy tanks was use white phosphorous shells. These were normally used to create smoke and mark artillery targets, but the sticky burning substance could also blind the optics of Panthers and Tigers, while the acrid smoke created by the phosphorous would get sucked inside the vehicle and make it hard for the crew to breathe. Naturally, the sheer fear of burning alive also had an effect on German tank crews, who sometimes abandoned their vehicles after being hit with such a shell.

In the end, Shermans armed with the 76 mm gun only debuted in Operation Cobra, the breakout from Normandy, and some outfits, including General Patton's Third Army, continued to refuse these versions until later on. Even once they began to appear in numbers, they only represented a limited improvement: Shermans with the 76 mm gun were good against later, upgraded models of the Panzer IV and the StuG III assault gun, but the guns were still inferior to the Panther's and the Tiger's guns; and, of course, the tanks carrying the guns were still less heavily armored.
 
Tank crews tried to fix the latter problem in whatever ways they could. Spare track segments, armor plates salvaged from wrecks, sandbags, concrete and even tree trunks were applied to the hull as field modifications in hopes of giving the crew better chance to survive enemy hits. Naturally, the tanks designers also got on the case.

The M4A3E2 Assault Tank, nicknamed Jumbo after the war, was built in May-June, 1944. While it still came with the old 75 mm gun (though a few were upgraded to the 76 mm one in the field), it had greatly increased survivability thanks to additional armor plating on the front and side of the upper hull, and on the turret. Jumbos could protect a column of regular Shermans by leading them and attracting enemy fire, most of which had little chance of causing serious damage. One particular Jumbo, Cobra King, became famous for being the first tank to reach the besieged town of Bastogne during the Battle of the Bulge.

Of course, the additional armor on the Jumbo made it heavy. It was both somewhat slower than other Shermans, put greater stress on the suspension system, and was more likely to get stuck in soft terrain such as mud or snow. The Sherman already had problems with its narrow tracks, which put greater pressure on the ground; the issue was exacerbated with the Jumbo's extra weight. This weakness was mitigated (both for the Jumbo and other models) with the addition of the "Duckbill", a set of connectors that could be added to the outside edge of the track's links, making them wider and distributing the tank's weight on the ground a bit more evenly.

Another notable variant was the Sherman Firefly, a British solution to the tank's other big problem, its inability to penetrate heavy tank armor. Designed in 1943, the Firefly actually preceded the 76 mm Shermans, and was present in Normandy on D-Day. The idea behind the tank was simple: just remove the normal gun and replace it with Britain's amazingly powerful Ordnance Quick-Firing 17-pounder anti-tank gun. Once the engineers started actually designing the thing, they realized the 17-pounder didn't really fit inside the turret. Not ones to give up easily, they decided to make the gun fit. A large metal box was fitted to the back of the turret, and the tank's radio was moved from its normal spot in the turret to the box to free up more space. The gun was also redesigned with an entirely new recoil mechanism, so it would only recoil 4 inches instead of 10. The breech (the opening where the shell is inserted) was moved from the top of the gun to its side to make the loader's job a bit easier. Note that the loader already had a pretty tough job: the shell was heavy, and his spot next to the gun was almost impossible to reach when entering the tank through the normal turret hatch. He had to crawl under the gun to enter or exit, which made it almost impossible for him to escape in an emergency. In the end, a brand-new hatch was added just to let the loader enter and exit the vehicle.

Another problem for the Firefly was running out of ammunition. Only 23 rounds could fit within the loader's reach. Additional rounds were stored in the front, where the assistant driver/bow gunner used to sit (and who was removed from the Firefly's crew), but there wasn't enough space to pass ammunition from there back to the loader. Once the first 23 rounds were expended, the tank had to retreat from combat, and the shells had to be lifted out of the tank through the machine gunner's hatch and put back inside through the loader's hatch before they could be used.

Though the Firefly was far from a comfortable tank, it was certainly powerful and capable of taking out the heaviest German tanks. The 17-pounder created such a bright flash on firing that the tank's commander and gunner needed to blink at that exact moment to avoid being temporarily blinded.
Fireflies were used in tandem with other Shermans: the regular models would be in the front, while a Firefly would hang back in a carefully reconnoitered spot to cover them. Once the Germans opened fire on the bait, the Firefly would spot them and take them out. Naturally, the Germans quickly became aware of this tactic and countered by targeting the Firefly first, since it could be easily identified by its much longer gun barrel. Many Firefly crews tried to disguise their tanks as regular (and less appetizing) Shermans by painting a part of their barrel white to make it look shorter.

One tenacious legend about the Sherman, often repeated in popular culture, is that their gasoline fuel made them very likely to burn out after being hit, while German tanks would not catch on fire due to using diesel. The legend is by and large false. It's true that some Shermans burned out, and the tank earned the nickname Zippo (after the cigarette lighter) from American crewmen and Tommycooker from the Germans ("Tommy" was a slang for British soldiers, while a "tommy cooker" was a World War I-era trench stove). However, the Sherman's liability to burn was greatly exaggerated: statistics show that the problem wasn't outstanding when compared to other tanks. Additionally, early studies showed that the fires that did occur had little to do with the fuel. Ammunition was stowed in sponsons in the tank's sides, and hits from the side could set it off. This weakness was fixed with the introduction of wet stowage: stowed ammo was surrounded by bins filled with a flame-retardant mixture. Any enemy shell hitting the stowage would necessarily hit these bins first, spilling their content onto the shells and thus preventing them from catching on fire. This measure greatly reduced Sherman burnouts.

All in all, the Sherman was a very reliable and solid tank, its difficulties against late-war German tanks notwithstanding. It's not surprising that numerous special-purpose modifications used the Sherman as their starting point. Some of Hobart's Funnies, the British-designed engineering vehicles designed to ease the D-Day landings (Read our earlier article – Hobart's Funnies) were based on the Sherman. The DD tank, short for "Duplex Drive" but also nicknamed "Donald Duck," was an amphibious Sherman that could disembark from a landing craft directly into the water away from the shore, swim to dry land, then continue on the ground. It had a distinctive appearance thanks to its propellers in the back and the canvas screen it could raise around itself as a flotation device.

Another Funny, the Crab, was an anti-landmine Sherman. It had a horizontal drum attached to the front, with steel chains hanging from it. Once the drum was spun up, the flailing chains would churn up the ground in front of the vehicle, hitting and detonating mines before anyone could drive or walk over them.

Other Shermans (and some other tank types as well) had plow-like cutting device, named "tusks" or "prongs" attached to their front and used to cut paths into the thick labyrinthine hedgerows of the bocage, the typical terrain in Normandy. Yet others were equipped with flamethrowers and used to clear out enemy bunkers and other fortifications both in Europe and the Pacific.
 
Another distinctive Sherman modification was the Rocket Launcher T34, better-known as the Calliope, named after a similar-looking musical instrument. The Calliope was a rack of 60 (in one version 64) tubes mounted on top the tank, with each tube holding a 4.5 inch (in one version 7.2 inch) rockets that could be fired one by one or as a single salvo. An upgraded version of the Calliope with heavier rockets was introduced as the Rocket Launcher T40 or Whizbang, but only saw limited use late in the war.

The Sherman's hull saw even more conversions than the full tank. It was used as the base for a wide range of vehicles, including self-propelled artillery, artillery tractors, bridging vehicles, armored personnel carriers, tank recovery vehicles and dedicated tank destroyers such as the M10 Wolverine.

The Sherman went on to see widespread service after the war. It was used by American and allied forces in the Korean War, and also saw extensive post-war use in both NATO armies and with other countries. The upgraded Super Sherman, officially the M50 and M51 models, continued to serve in the Israeli army until the early 1980s, providing testimony to how much longevity you can get out of an old but solid design.

Being such an iconic vehicle and surviving in such high numbers, it's no surprise that the Sherman became a common sight in World War II movies, and these appearances furthered its reputation. Films such as A Bridge Too Far and TV series like Band of Brothers and The Pacific pay tribute to the tank, depicting its historical exploits. It even appears in less-than-historically-accurate productions, such as the hilarious war heist/comedy movie Kelly's Heroes, which features Sherman tanks leased from the Yugoslavian army, which used them during the Cold War despite being a communist country.
Perhaps the best-known Sherman tank these days is Fury, the tank featured in the eponymous war film starring Brad Pitt. It's interesting to note that while the tank "plays" an M4A3E8 Easy Eight, the actual vehicle used for the filming is a very similar but much rarer M4A2E8 prototype. Today, the tank is on display at the Bovington Tank Museum in England, and you can see it with your own eyes on our Britain at War Tour, set to debut in 2023. If you are lucky, maybe you can even see it on one of our D-Day Anniversary Tours, since it is a frequent participant of the celebrations in Normandy.