The M4 Sherman, Part 1

The US military has a reputation for making their equipment last a very, very long time. The A10 Thunderbolt II was first introduced in 1977. As of the time of me writing this, 2016, it is expected to stay in Air Force service until 2040. Since its introduction, the most significant change of any kind to the A10 has been the addition of enhanced avionics and a targeting system.

A lot of people say this plane is ugly. They are wrong.

A lot of people say this plane is ugly. They are wrong.

 

Both the M1 Abrams tank and M3 Bradley Armored Fighting Vehicle were introduced in 1980 and 81 respectively. They show no signs of being phased out within the next decade.

 

My point is that we get a lot of damn use out of our equipment. Far more than other nations, which undergo significant military modernizations every decade or so. And yet, US equipment remains some of the best in the world.

 

Before the Thunderbolt II, before the Abrams, before all that, was the trend setter: The M4 Sherman tank.

You may recall this from my previous entry. This is a Sherman from the 761st tank battalion, crossing a bridge.

You may recall this from my previous entry. This is a Sherman from the 761st tank battalion, crossing a bridge.

I can’t say that the Sherman was the greatest tank of World War II. That title goes to either the Panzer V Panther, or the USSR’s T-34. I can, however, say that the Sherman was easily the most unimaginably versatile tank of the war.

So you can scoop while you scope and shove while you shoot.

So you can scoop while you scope and shove while you shoot.

 

Most tanks had a singular role. Light tanks like the M22 Locust were primarily used as fire support for foot soldiers (and occasionally rolling cover).

The M22 Locust, a good example of a light tank.

The M22 Locust, a good example of a light tank.

Medium, or Main tanks, like the T-34 and Panzer IV[picture], were armored fighting vehicles used as weapon platforms for use against enemy infantry, fortifications, and other tanks.

A T-34-85. It mounted a bigger cannon than the average T34, but you can get a good sense of scale here.

A T-34-85. It mounted a bigger cannon than the average T34, but you can get a good sense of scale here.

 

Heavy tanks, like the Tiger and IS-2[picture], were functionally mobile fortifications, able to endure direct engagement with other tanks and fixed positions in either an attacking or defending capacity, and usually mounting a heavier cannon than its smaller peers.

Tiger 131. Captured by the British in WWII and moved back to England in total secrecy. It stars in the movie Fury. No, really.

Tiger 131. Captured by the British in WWII and moved back to England in total secrecy. It stars in the movie Fury. No, really.

There are other classes of armored fighting vehicles, but we’ll stick with those basic 3 for now.

 

The Sherman was an oddity. Its main function was that of a main battle tank, but it rapidly became so much more. By the end of the war, the Sherman had been used as a main battle tank, a tank destroyer, a flamethrower system, a rocket launcher assembly, a recovery vehicle, an amphibious recovery vehicle, an amphibious tank, a modular bridge system, a heavy tank, a bulldozer, and a mine flail.

Sherman BARV Beach Armored Recovery Vehicle. Amphibious.

Sherman BARV Beach Armored Recovery Vehicle. Amphibious.

 

What’s a mine flail? It’s the craziest, yet most effective way to clear a mine field. I’m not joking.

 

Furthermore, a combination of lend-lease and practicality made the M4 Sherman a contender for the World War II tank used by the most nations at once. Even after the war, various models of it saw use in Korea and Israel.

 

During World War II, there were several base models of the Sherman produced, around which all those various uses were further developed. I’ll frame my explanation of the different production variants around the designations (M4A#, 75 or 76 or 105, VVSS or HVSS, W or non-W, Assault kit). All models were used from the time of their introduction to the end of the war and beyond.

The M4 was the first production model, and all the first batches were delivered to Britain through Lend-Lease. This first model’s hull was built from cast-plate panels, with the plates bolted together from the inside. This would be among the first things changed in later models. For simplicity, I’ll just cover the American models and sub-variants, and save the lend-lease and irregular models for a second post.

M4. Thanks to http://www.tanks-encyclopedia.com

M4. Thanks to http://www.tanks-encyclopedia.com

The M4A1 was the first advancement, and the most immediate noticeable change was the hull. It was now constructed from a single cast piece of rolled composite steel. In addition, it was powered by a modernized engine compared to the M4.

M4A1. Thanks to http://www.tanks-encyclopedia.com

M4A1. Thanks to http://www.tanks-encyclopedia.com

The M4A2 was built with a welded, rather than cast hull. The rear section of the hull, around the engine, was notably different from previous models. The engine itself was now a diesel-powered engine built by General Motors. Diesel was the preferred fuel on the pacific front, owing to a lack of other readily available fuels for ground vehicles.

M4A2(76)W HVSS. Thanks to http://www.tanks-encyclopedia.com

M4A2(76)W HVSS. Thanks to http://www.tanks-encyclopedia.com

The M4A3 featured a new liquid-cooled engine, and special armor augments around various internal components.

M4A3. Thanks to http://www.tanks-encyclopedia.com

M4A3. Thanks to http://www.tanks-encyclopedia.com

After the base designation, there is often a number contained in parentheses. This number indicates the type of cannon mounted on the tank. (75) was a 75mm cannon , firing the 75x350mm cannon ammunition. [Most of the above images show the 75mm cannon]

(76) was the improved 76mm cannon, which had better ballistic and armor piercing performance than the 75. I can’t find the ammo dimensions for the 76, and that’s kind of bothering me. [The M4A2 above is mounting a 76mm]

 (105) indicated a tank that had its cannon replaced with a 105mm howitzer. Most 105mm mounted Shermans were intended for direct infantry support and mobile artillery operations, rather than full tank operations.

M4 with 105mm Howitzer and HVSS. Thanks to http://www.tanks-encyclopedia.com

M4 with 105mm Howitzer and HVSS. Thanks to http://www.tanks-encyclopedia.com

 

VVSS or HVSS indicated either Vertical Volute Spring System or Horizontal Volute Spring System.

VVSS was the more common type of suspension, but it wasn’t always as reliable as crews would have liked. It provided steadfastly mediocre stability, and occasionally got tanks into trouble they couldn’t maneuver out of, like mud, and anywhere else where traction was sparse.

HVSS was not all *that* much different, but was better at weight distribution and stability while the tank was moving.

 

A W in the designation indicated Wet Stowage. This requires me to explain something about Germany’s guns first.

The most common round used by German tanks and field guns was thePzgr (panzergrenate). This was an armor piercing high explosive round. Basically, the Pzgr was a hard metal casing designed to go through armor, surrounding a fuse and explosives. After hitting a solid enough target, the fuse activated after a millisecond delay and detonated the round. The delay was such that there was very little time between a successful penetration and the detonation, and would ideally detonate the round in the middle of the target’s hull. A penetrating hit from a panzergrenate was devastating. If such a round were to pierce a Sherman by the ammo rack, it stood a good chance of igniting the ammunition being stored there, setting off a chain reaction and completely destroying the tank and anyone in or around it.

Thanks to MI5 or the OSS.

Thanks to MI5 or the OSS.

To prevent this, some Shermans were outfitted with Wet Stowage. A special casing was built around the ammo rack and filled with water. If a round penetrated the rack, it would flood the ammo with water, rendering it inert, even when the Pzgr detonated.

Finally, the Assault Kit. Though no one often called it that. Some Sherman tanks were outfitted with a secondary layer of armor around the hull and turret. These M4s were generally classed as “Jumbo” Shermans, and had E# after the M4 in their designation (M4A3E#). This augmented armor kit allowed a Sherman to withstand a direct frontal hit from a German 88mm cannon, the main gun of the feared and respected Tiger tank.

M4A3E2. Note how the ball turret in the hull appears "shrouded" by the armor plate. Thanks to http://www.tanks-encyclopedia.com

M4A3E2. Note how the ball turret in the hull appears "shrouded" by the armor plate. Thanks to http://www.tanks-encyclopedia.com

 

Just to give an example of how one of these Sherman’s full designations would go. An M4A3 with wet stowage and a 76mm cannon, as well as a Horizontal Volute Spring Suspension, would be designated M4A3E2 (76) W HVSS. It looks complex, but it’s just made up of a standard set of indicators.

 

I’ll go into the more unusual and lend-lease variant Shermans in my next post.