Of the many armored fighting vehicles in recent history, none other is quite so famous (or, rather, infamous) as the American M4 “Sherman” Medium tank of Second World War vintage. Indeed, it has many less than flattering nicknames, more than its share of well-documented and supposedly irrefutable criticism, and an overall bad reputation. Authors of books such as Death Traps: The survival of an American Armored Division in World War II are best sellers particularly because its whole premise is negatively scrutinizing the venerable Sherman, its designers, and even the country that it originated from.

These days, in the WWII enthusiast circle, “Sherman” is practically a bad word. But does it really deserve all this criticism? I don’t think so. There is a minority of people who will argue in favor of the tank saying that it was well suited to mass production and that this was a strength (arguably the only one that mattered in the end) in its own right. I utterly refuse to fall back on this argument because I feel that it is somewhat flawed. If the fates had been reversed where the Germans were producing M4s and the United States was producing any given panzer, which one do you think would have outnumbered the other? Here’s a clue: It’s not the M4.

In my experience watching television documentaries, reading various encyclopedias, and general wikiality there are a number of common misconceptions about the M4 Sherman that need to be understood by any self respecting tread-head.

Nicknames: Ronson, Tommy Cooker

It’s not exactly positive just when the M4 might have picked up these names, but it is understood that they had them. Both of these nicknames were in direct reference to the common attribute of the Sherman tank to experience a catastrophic explosion or otherwise burn upon being struck by a German anti-tank shell. Ronson is a lighter company whose slogan at the time was along the lines of “…lights the first time, every time,” hence the reference. The Tommy Cooker is known to have been an English Army field stove used in WWI and in limited service in WWII, but this alone probably isn’t connected to the nickname – it probably has more to do with the gruesome fate of “tommies” (German slang for Englishmen) who were trapped inside the burning hulls of their steel mounts.

There is some question on whether or not “ronson” was a wartime nickname or not. To my knowledge there exists no period document, be it a page from a diary or a field report, of anyone actually calling the M4 tank a ronson. It seems highly likely, given this, that the nickname is in fact a post-war title. This would parallel the myth of the Republic P-47 fighter-bomber being nicknamed the “jug” during the war, when in actuality the wartime namesake was “juggernaut” and a shortened version of this (jug) was only adopted during its post-war service.

But the fact remains that the Sherman did carry numerous negative titles associated with its tendency to burn. Anyone who is like me will become quickly agitated at how, whenever there is a debate about this particular subject, the opposition will bring it up as if you have honestly never heard it before. Of all arguments against the Sherman, this one pops up the absolute most. Luckily, it is also the easiest to combat. You can always tell a “newbie” tread-head from a more experienced one by whether or not their argument focuses on this specific trait or not.

It must be understood that the M4 underwent numerous upgrades during its service life, and almost immediately this characteristic of the tank in combat was sighted, identified, and looked into. Say what you want about the United States, but it put a higher investment in the lives of its soldiers than many other armies of the day. First of all, burning upon penetration is not something that was exclusive to the Sherman. In fact it was common practice in armored warfare to keep hitting an enemy vehicle until it started burning in order to ensure a kill. But even without this, German tanks such as the Pz.Kpfw IV were prone to burning upon initial penetration. The much vaunted Soviet T-34, too, was highly volatile in this respect and had its own little nicknames and slogans attributed to it.

The United States moved to fix this defect quickly, as said before. It is often said that the United States’ usage of gasoline rather than diesel fuel for its vehicles made them more prone to catastrophic ignition. This, however, is a bit of an exaggeration and any television documentary (this is a popular mistake with British telecasts in particular) should hang their heads in shame. Shame, I say. Because, in fact, many German tanks were using gasoline as well. The Soviets were using largely diesel engines for their tanks which, while giving somewhat better automotive performance, also shared a knack for “brewing up.” In addition, American testing observed that the M4 would burn even with empty fuel tanks.

This myth about gasoline originates from the 1970 film, Patton, in which the character of Omar Bradley states that “their tanks are diesels,” and that the Sherman would go up in flames whereas theirs [The Germans] would not because of it. Remember, people – don’t get your “facts” from Hollywood.

The problem was traced primarily to ammunition storage. While most contemporary vehicles were storing shells in the turret and hull floors, the M4 had no such protection and wedged its ammunition on the sponsons of the vehicle. As a result the highly explosive payload of the M4 was exposed and there was a very good chance that a shell, especially one designed to explode upon penetration, was going to detonate these cartridges. The early and mid-production runs saw a band-aid solution in the welding of appliqué armor plates over the ammunition. The late production run saw the removal of these and finally relocated the ammunition storage to a more secure location. In addition, a new means of storing the ammunition was devised wherein the racks were surrounded by watertight jackets filled with various fluids which would burst open if the ammunition was at risk of exposure.

Different sources will list different statistics as to how much this actually helped. Some cite 60-80% reduced combustion rates by the end of the war. Tanks equipped with wet storage made up 73% of the late production run with 13,774 samples built. Vehicles equipped with the new storage system were given a “w” designation after the model.

Long gun =/= Sherman Firefly

Prior to Operation Overlord the English were desperate for vehicles to fit their otherwise excellent 17-pounder cannon. They had tried to get many vehicles to accept the gun, including their own home-grown Cromwell cruiser tank chassis in the form of the Mk VIII Challenger. A superior and more readily available solution, though, was found in the ever-adaptable American tank. Due to the size of the bubble-shaped turret the gun had to be turned by ninety degrees to just barely fit and several features of the vehicle needed to be modified or outright deleted.

The resulting tank, the Sherman IIC or VC “Firefly” by British nomenclature, is hailed as the finest Sherman type to have existed during the Second World War and, indeed, it did have the best gun out of all of its war-time variations. Pop-history sources such as television documentaries will tell you that the Americans (being the epitome of evil that they supposedly were) refused to accept a foreign gun for mass production so that American Sherman tanks were forever stuck with the inferior (in certain capacities) 75-mm M3 cannon of infamy.

This, of course, ignores the fact that the U.S. was already fielding the British 6-pounder OQF antitank gun renamed to the 57-mm M1 with only minor modifications to fit U.S. standards. Clearly, the “states had no qualms about using superior equipment just because it was from Great Britain. This accusation also ignores the fact that the United States had already brought an up-gunned version of the M4 online and was ready to deploy it in the weeks following Overlord. This change, which ushered in what we know as the late production run, was significant as it made radical improvements to the firepower and armor protection of the tank. More on the armor later.

A brand new turret was selected for the tank which was larger and better protected. It was the same turret which was tested for use on the T23 Medium Tank which was slated to have replaced the M4 in 1943, but couldn”t because pausing M4 production to retool factories would have been unacceptable. Having more room in the turret allowed for the fitting of a larger gun without seriously compromising the crew and features within the tank itself. A new gun, called the 76.2-mm M1, was created by combining a modified 75-mm M3 breech mechanism with the barrel of the 3-inch M7 which was serving as the armament of the M10 “Wolverine” Tank Destroyer. This gun was much more capable against enemy armor than the 75-mm M3 which came before it.

In a direct comparison, the 17-pounder cannon trumps the 76.2-mm M1 pretty harshly. It is a flatter trajectory weapon with a higher velocity and better armor penetration qualities. However the upgrade to the 76.2-mm M1 effectively put the M4 back on par with the Pz.kpfw IV in terms of firepower and, given the right type of ammunition, was a serious threat on the battlefield even against such celebrated tanks as the infamous “Panther.” These American tanks also had the benefit of a larger turret over the firefly which greatly increased the efficiency of the crew.

By 1945 roughly 50% of American Sherman tanks in Europe were armed with 76.2-mm guns. A total of 10,703 tanks armed with this gun were produced during the Second World War and it alone constituted 57% of the late production run. Tanks armed with this caliber gun were given a (76) designation following the model.

A mistake many game and movie makers commit when looking to include these up-gunned Shermans in their products (The movie “Kelly”s Heroes’ is an example) is to use the M4A3E4 model to represent a proper M4A3 (76)w. This is incredibly wrong. The M4A3E4 is a Korean War modification of the stock M4A3 Sherman in response to the need for capable tanks in Korea. By retrofitting the American 76.2-mm M1 into the “old” style bubble turret (in much the same way as the British shoehorned their own weapon into the Firefly) a stopgap was created until better equipped units could arrive to the front.

Tin-foil armor

It is often said that the M4 suffered from the fatal flaw of paper armor. This is quoted by many “experts” in the field and is one of the prevalent criticisms of the Sherman. In fact, historians of the Juno Beach Centre in Canada have gone on record with the following quote:

“The Sherman, meanwhile, was designed in keeping with American armoured doctrine, which established that the main purpose of the tank was to disrupt enemy infantry and communications. This doctrine, and the tank it produced, were to prove inadequate for the type of tank-versus-tank combat that occurred in Normandy. Heavy armour and a powerful gun were needed to stand up to the latest German tanks, and the standard Sherman had neither.”

In order to look at this objectively we need to guess what the quoted party means by “standard,” and how much armor these standard models of the tank actually had. Then we need to actually compare it to contemporary vehicles.

The M4A3, since its introduction, was the “standard” model of medium tank for the U.S. Army chosen because of its more powerful power plant and welded construction over, say, the M4 and M4A1 – both of which used an inferior engine and, in the case of the M4A1, inferior cast armor that was not up to par with welded rolled homogenous steel plates. The M4A2 used disel fuel and was therefore mostly an export vehicle save for some going to the USMC in the pacific, and the M4A4 was dedicated to lend-lease outright.

When the M4A3 was first brought into action, the glacis plate (the most important plate on the tank, mind you) sported 51-mm of steel sloped at 56°. Going by the “armor basis curve” outlined in the WO 185/188 DDG/FV(D) Armor Plate Experiments, a slope of 55° (the nearest value) gives an armor effectiveness multiplier of 2.12. This, of course, equals 108.63 equivalent thicknesses in its glacis plate. To be honest, that is not too shabby! The problems are numerous, though.

First of all, these early and mid production Shermans featured two protrusions on the glacis plate in order to house the drivers’ hatches and, earlier, the view ports. These features formed a shot-trap (meaning an area that will ease the penetration of an incoming shell) and to have such a weak spot on the most important armor plate of the vehicle, never mind two, is a critical design flaw. It cannot be seen as anything but an engineering failure that should be dully noted and never repeated.

The next problem is that of overmatching. “Overmatching” is a term applied when a plate of armor has a greater thickness than the incoming shell’s diameter. Or the other way around – when the diameter of the incoming shell is greater than the thickness of the plate. The effect of overmatching is exponential and not constant, meaning the more and more a shell overmatches a plate of armor the more and more effective it is going to be. It is why tanks such as the Pz.Kpfw VI ausf E “Tiger” enjoyed generally successful protection even though it did not share the benefit of sloping. In the cast of the Sherman, the most common rounds thrown against it were of the 57-mm, 75-mm, and 88-mm diameter varieties. The armor was more than sufficient to stop 57-mm projectiles, but showed weakness against 75-mm projectiles and down right impotency against 88-mm projectiles.

The third problem, which would sadly never really adequately be corrected, was that American manufactured armor plate was never equal to that of German plate. Even without considering face-hardened armor, German RHA was typically harder than American RHA, but not so much so as to be brittle. German plate was nestled right in the comfort zone, along with British plate, to produce vehicles which were superbly protected by this fact alone. In contrast, American armor tended to be relatively soft and offer less resistance than it should have. On the other side of Germany, Soviet steel was so hard that it was actually very brittle and prone to shattering. You can see that tank design isn’t a simple matter of putting any old steel on a frame!

For the late production run, along with the upgrades to firepower that were made with the inclusion of the 76.2-mm M1 gun, the glacis plate was reshaped and thickened. It had changed from 51-mm thick to 64-mm thick, and its slope lessened from 55° to 47°. This new hull, going by the previously stated armor basis curve (rounded to the nearest given value of 45°,) had a multiplier of 1.69 due to the slope, making the 64-mm thick plate equivalent to 108.16 thickness.

This isn’t much of an increase on its own. In fact, it’s a bit of a decrease. However, by reshaping the hull, American industry was able to delete the two shot-traps which previously plagued the tank. In addition, the 64-mm thick plate proved highly resistant to 57-mm projectiles, as well as having a fair shot at defending against 75-mm hits. 88-mm still dominated the tank, but I can’t think of a whole lot of tanks in the Shermans’ weight class that weren’t regular victims to such a caliber.

So now we have a good idea of the kind of protection the Sherman Tank had. What about its contemporaries? Well, first, we must define what it’s contemporaries are. For the sake of simplicity, I will compare the Sherman to the T-34-85 and the Pz.Kpfw IV ausf. H. It can be argued that the Pz.Kpfw V “Panther” is a contemporary to the M4, but in sheer weight of numbers the mark IV was the primary medium tank of the Wehrmacht up until such a point that, well, Panthers didn’t much matter any more.

Glacis Plate Comparison

[Subject]: [Armor]: [Algorithm]: [Result]

Pz.Kpfw IV ausf H: 80-mm@10°: 80*1.01: 80.8 effective

M4A3 (76)w: 64-mm@47°: 64*1.69: 108.16 effective

T-34-85: 45-mm@60°: 45*2.5: 112.5 effective

Superior Mobility

This is one specific trait where the M4 Sherman tends to perform well even with those who criticize it for all of its other faults. In a fit of irony, the tables turn depending on how you look at the problem. It is well known that the M4 had a higher ground pressure thanks to its narrow tracks on the early versions and this caused a considerable problem on soft ground. In United States vs. German Equipment by Major General Isaac D. White, soldiers of the U.S. 2nd Armored Division were (almost) unanimously displeased with the off-road performance of their vehicles in comparison to the Mark V “Panther,” which that book was using as a standard by which to compare the M4 to.

This feeling of resentment towards the off-road trafficability of the M4 gravitated towards two primary issues:

• The M4, weighing roughly thirty tons, sunk anywhere between four to six inches deep into soft earth where as the Mark V Panther, weighing roughly forty-five tons, never exceeded two to three inches. This was due to the wider tracks of the Mark V “Panther” relative to its increased weight, giving it a lower pressure per square inch than the M4. A make-shift solution was to add “duckbill” paddles which connected to the ends of the tracks and added a small amount of extra width. The satisfaction of the troops with this method varied, with some finding it adequate and some utterly hating it. All agreed, however, that the tracks needed to be permanently widened and this came with the HVSS suspension later seen on improved models of the M4. Unfortunately, although the prevalent Sherman suspension in the U.S. Army in the post-war world, it was a sparse feature during the war.

• The Mark V could turn in place whereas the M4 could not. In fact, the M4 had to ensure a turning radius of roughly nine and a half feet. This was seen as a major disadvantage as the M4 could not as quickly adapt to changing tactical situations where a simple pivot of the tank was called for.

On the other hand, however, German Panzer crews spoke relatively highly of the M4’s cross-country mobility, although admittedly this was before the Mark V was issued to such units. This can be seen in the following quote:

“On the Southwest Front, opinions are in favor of the Sherman tank and its cross-country ability. The Sherman tank climbs mountains that our Panzer crews consider impassable. This is accomplished by the especially powerful engine in the Sherman in comparison to its weight. Also, according to reports from the 26.Panzer-Division, the terrain-crossing ability on level ground (in the Po valley) is completely superior to our Panzers. The Sherman tanks drive freely cross-country, while our Panzers must remain on trails and narrow roads and therefore are very restricted in their ability to fight.

All Panzer crews want to receive lighter Panzers, which are more maneuverable, possess increased ability to cross terrain, and guarantee the necessary combat power just with a superior gun.” – Albert Speer, November 1944

Ironically the Sherman variants that used aircraft engines, the M4 and the M4A1, were the less powerful of the bunch. The M4A3 with its Ford V8 had a higher power-to-weight ratio.

The author of Commanding the Red Army’s Sherman Tanks, Dmitri Loza, was a veteran of the eastern front and hero of the Soviet Union. He is rather unique in that he served in a unit of M4A2 Sherman tanks and has plenty good to say about it. Although the M4’s mobility, in any variant, wasn’t up to par with the exceptional ground pressure and power-to-weight ratio of the T-34 its rubber padded tracks offered the M4 a longer track life and increased strategic mobility.

Dmitri highlights two weaknesses of the rubber pads, however. The first of which, having been corrected in short order, was one which was experienced by American and British crews as well. On icy surfaces the tank would “slip and slide” around! I have seen footage of this, and trust me it is a hilarious thing to see. The fix issued was special pads with grousers in them to give the tanks traction. The other disadvantage was that in exceptionally hot weather the rubber was prone to sheering off the tracks and disrupting movement. It should be noted that the M4 had many types of track links, some of which were all-steel like those of its contemporaries.

Sources

• American Armored Fighting Vehicle Database
• wwiivehicles.com
• Panzerworld
• The Russian Battlefield
• The Sherman Register
• Isaac D. White. United States vs. German Equipment. Merriam Press
• R.P. Hunnicutt. Sherman: A History of the American Medium Tank. Presidio Press
• WO 185/188 DDG/FV(D) Armor Plate Experiments. National Archives
• Special thanks to the Tanks in World War II Forum