Category Archives: 75mm Turret

# 15 Turrets: They Are The Combat Power Of The Tank

Turrets: They Rotate, and have Guns

Cute puppies!
Marine Cleaning his Tommy gun on a Late model M4A3 75 Sherman. Note the all-around vision cupola with periscopes mounded in the center of the hatch.

The Sherman had two turret types the 75mm turret and the later T23 turret with the M1 series of 76mm guns. The Jumbo had an up-armored version of the T23 turret.

split hatch details

One of the things that really set the Sherman apart from its peers, and gave it very good longevity, was the size of the turret ring. The Shermans were 69 inches, positively huge for when it was designed, the early T-34 had a 56-inch ring, and the later version with an 85mm gun had a 63-inch turret ring. Nazi Germans are not very good in this area, PIII having a 60-inch ring, PIV having only 63 inches, and the Panther only having a 65-inch ring. Even the Tiger wasn’t huge, at only 70 inches! So what makes the size of the ring important? It is one of several factors that determine the maximum size gun you can mount on the tank. The other factors are the mechanical reliability of the vehicle and its load capacity, and how good the country building the tank was at making recoil absorption systems for the guns. The combination of automotive reliability, load capacity, turret ring diameter, and turret size allowed the Sherman to be up-gunned for decades. These factors were far more important than armor thickness when it came to the Shermans longevity. That the Sherman received more powerful guns than the Panther had, or could have had, is just one more reason why the Sherman was such a great tank, and better than the Panther.

turret collector ring
The turret collector ring allowed the turret wiring to go into the hull and still allow a 360-degree traverse and not tangle any wires. All Shermans had essentially the same one.

Now let’s talk about turret drive motors.  There were three types used on the 75mm Shermans.

Oilgear: All models of Sherman tank had both powered and manual turret traverse. They did try various brands and types though. The preferred on the early Shermans were the hydraulic mechanism made by Oilgear Company. The Oilgear unit was more precise because it had veritable sensitivity and more robust since it was able to keep the turret spinning even with minor flaws in the race or ring gear, than the other choices. Oilgear could not keep up with all the factories producing Shermans, so they had to go to other companies.

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The Oilgear traverse system and gunners station in an M4A2 76 HVSS tank
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The Oilgear Traverse System, and foot pedal triggers, and elevation wheel in a restored M4A2 76w HVSS tank

The Oilgear unit was hydraulic but powered by its own electric motor that spun a hydraulic pump and turbine set up to rotate the turret. The whole assembly was small enough to be mounted to the side of the turret, with a fair amount of room for the gunner.

Logansport: This Turret drive was very similar to the Oilgear unit, just not as precise, nor as good at dealing with imperfections in the turret race or ring. This unit was so similar the electric motor powering the hydraulic pump and turbine used the same reduction gears as the Oilgear unit.

The Logansport unit used the same mounting bracket as the Oilgear unit as well. The sensitivity to problems with the tolerances on the turret ring would make this drive more likely to fail from minor damage that the Oilgear unit would shrug off.

Westinghouse: The Westinghouse unit was just a big electric motor hooked to reduction gears. Since the motor ran at a faster speed, it had to be adapted to the stabilizer system but was still able to fit the same space and use all the mounting brackets of the other systems.

M4A4 Armament diagram westinghouse traverse 75mm early turret
Westinghouse traverse controls

The Westinghouse unit had the same problem with minor flaws in the race or was sensitive to tightness in the ring gear.

Now, this would be a quality assurance problem at the factory in most cases. IE, when the tank got to the end of the line, and the QA inspector rotated the turret, and it screeched and slowed down over 10 degrees of rotation, it would be rejected, and sent to the factory’s QA shop to be fixed.  Battle damage might have caused some problems as well, but if the tank took enough of a hit to damage the teeth on the ring, or gear, it was probably going to be knocked out, and in really bad shape. That speculation based on how well many turret rings held up after years on firing ranges when the wreck they were in was restored into a beautiful working tank.

On the later T23 turrets, the Oilgear system was used for traverse control and an improved Westinghouse stabilizer was used as well.

The Westinghouse stabilizer: All models of the Sherman but the 105 armed tanks had a stabilizer to control the main guns in elevation while on the move. It used a gyroscope and hydraulic power pulled from the turret drive system to keep the gun steady in the vertical while on the movie. The system is often disregarded as an advantage by detractors, for a few reasons, but none are valid in a technical sense. The stabilizer was a very advanced piece of kit, and something the Germans could not copy, and never installed a similar system on a wartime tank. That it was complicated and the crews lacked training in using it, doesn’t mean it didn’t work and offer advantages to crews who bothered with it.

The original stabilizer was a little complicated to set up properly since many armor units received their tanks and maybe some manuals for them, when they formed, they often did not have a single man in their company who really knew how to make the stabilizer really work. This lead to it being turned off by a lot of early war crews. The wrongheaded belief the equipment was useless followed that. The Army did a test on it and found the stabilizer, when set up, and used by a crew who knew how to use it, it helped a great deal in getting off a fast first shot when the tank came to stop to shoot.  If the tank rocked, the gun stayed more or less on target. This was a big advantage to getting that all-important first shot/hit in combat.

The Westinghouse stabilizer was improved and simplified in the second generation Shermans, the large hatch 75 and 76 tanks would have gotten it.  It was easier to set up and maintain, and the Army worked on getting crews trained on it.

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M3 2 inch Mortar

The M3 2 inch Smoke Mortar:  The M3, 2-inch smoke mortar was installed in the turret, with the muzzle opening on the forward left of the turret, on both the 75mm and 76mm gun turrets.  It was added to the tank at the request of the British and was loaded and fired by the loader. The mortar was loaded from inside, but protruded into the loader’s space, and was not well-liked. It could only be aimed by rotating the turret, and not all late model 75mm and 76mm turrets got them. Postwar, most were removed and the hole welded over.

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An M4 Composite hull, probably in the Philippines, with a good shot of the late model, split commanders hatch

The Hatches:  The Sherman’s turret started off with a single large split commander’s hatch. This hatch incorporated the m2 .50 HMG mount and rotated. It also had a standard periscope mounted on one side of the split hatches. This hatch went through several changes throughout its long life. Initially, the split commander hatch just depended on the weight of the armored hatch cover halves to hold them in the 45-degree angle position that sat in when open. They could be knocked loose when the tank was moving over rough terrain, and really hurt the commander.  They added a pair of hatch locks at the factory and fixed them in the field with kits. The final version of the split hatch had internal springs in the hinges to hold them open. There was also a version with a defect that passed factory inspection that showed up on some M4A1 76W tanks, where the split loaders hatch, essentially the same hatch that had been the commander’s hatch, was used for the loader, .50 M2 mount, and all.  This was fixed pretty quick though, and then the hatch was replaced by the oval loaders hatch.

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In this massive image of an M4A1 76w tank, that has been modified with a flamethrower, after being repaired, note it has the split loaders hatch with the flaw that won’t let them open all the way.

When the second generation Shermans with the T23 turrets went into production, they all got much improved all-around vision cupolas. There must have been a shortage of contractors who could make it, because it was in short enough supply, the second-gen large hatch, M4A2 75s, M4 Composite hulls, and M4 (105) tanks were all built with the original split commanders hatch.  The all-around vision cupola production was reserved for tanks armed with the M1A1 gun.  The cupola offered very good all-around vision, with six armored glass viewing blocks, that were all replaceable, and a larger periscope mounted in a rotating center section of the hatch door. Towards the end of the war, the new cupola became more available and was fitted to some of the ultimate production M4A1 75, M4A3 75w tanks, and M4A3 (105) tanks.

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in this nice photo of an early production M4A1 76w Tank with the split loaders hatch. It’s also a pretty good shot of the all-around vision cupola

The oval Loaders hatch: The version of this hatch on 75mm turrets looked the same but was slightly smaller than the one used on the T23 turrets. The hatch was a spring-loaded oval hatch, either just big enough to get through or, big enough to get through comfortably, in the T23 versions. On the T23 turrets, when the oval hatch was installed, a new fully rotating periscope foreword of the hatch replaced the one that was mounted in the old split hatch.

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Soviet M4A2 76W tanks with oval loaders hatch.
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A late production M4A2 75 with a large hatch hull, oval loader’s hatch, on what is probably a high bustle turret, with a split commander’s hatch.

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Now for a final bit of information on the turrets and the stuff mounted on them. Over time the turrets picked up an external vane sight the commander could use to roughly put the gunner on a target, it looked like a whale fin in front of the commander’s hatch on older 75mm Shermans. This was refined into a more useful, and less odd-looking site that could be used from inside or out of the turret.  The .50 caliber machine gun mount started on the commander’s hatch, eventually moved to the loaders hatch, and then to the middle between the two hatches.  There was also a spotlight mount added, and it ended up being on late 75mm turrets, the T23 76mm turrets, and even retrofitted to older 75mm Shermans.  The mount had an armored plug, the spotlight plugged into, and could be controlled from inside the tank, much like the spotlights you see mounted to the side of police cars. The turrets also started out with no brackets for storing the heavy machine gun, but they started showing up on 75mm turrets and were on almost all T23 turrets.  Even where the lifting eyes were moved around on the turrets.

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From looking at period pictures, it was very common for the gunner or loader to ride standing in the commander’s hatch, while he was in it as well, the split hatch cupolas were that big. I thought I wouldn’t see the practice on tanks with the all-around vision cupola, but I found a few where the crews did it there too.

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This Marine M4A1 in the jungles of Cape Gloucester has its commanders hatch being shared by two crewmen

 

Riflemen of the 29th Marine Regiment ride a M4A3 Sherman 105mm of Company A, 6th Tank Battalion during the 6th Marine Division's drive on Chuda along the west coast of Okinawa. After expecting a contested landing on April 1, 1945, and seeing little of the Japanese, the Americans were in high spirits as objectives are taken ahead of schedule in Northern Okinawa; the Shuri Line would rob them of their high morale. The 29th Marines cut off the Motobu Peninsula and seized Chuda at 1200 Hours on April 6, 1945. Tank-infantry teams encountered sporadic resistance during the initial invasion; most problems were from the Japanese blowing bridges as they retreated inland. Destruction of bridges had been inept; frequently only a span of the bridge had been blown or cracked. The engineers cut quick bypasses for the vehicles, repairing the broken spans later. 500 M4A3 Shermans with the M4 105mm gun were built in late 1944. Later versions of the 105mm Sherman had a more advanced horizontal volute spring suspension (HVSS) with wider tracks that allowed for a smoother ride. Note partially dismantled deep wading gear to allow the M4A3 to move through deep water during the landings a few days before. The M4A3 Sherman with the M4 105mm howitzer was not popular with the tankers, who preferred the M1 76mm high-velocity gun in case of tank-against-tank engagements. However, the 105mm-equipped Shermans were very popular with ground troops, who used tanks as mobile pillboxes, taking out Japanese positions with point-blank high explosive fire.
On this M4A3 105 in Marine Service, you can clearly see the commander and probably gunner sharing the all-around vision cupola!
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An Army M4A3 75 tank with a split commander’s hatch, oval loaders hatch, and the commander and gunner sharing the split commander’s hatch, somewhere in the Philippines.

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An M4A4 that has been modified to take a different motor, with a mid-production 75mm turret, with split commanders hatch, and a welded up pistol port. It also has the stubby mantlet, and you can just make out the original commanders vain sight in front of his hatch

 

The standard 75mm Turret:  The Sherman’s First Turret, It Had Many Minor Changes

The standard 75mm turret started out with a stubby rotor shield that just covered the base of the 75mm gun. These early turrets didn’t have a direct telescopic sight for the gunner either. The gunner had to rely on the M4 periscope to aim the gun. The turret had one large hatch for the whole turret crew to get in and out from and a pistol port on the loader’s side that could be propped open and spent 75mm shells dumped out.  The loader and commander had fully rotating periscopes to view the world through, the commander’s periscope was in his hatch, the loaders right above his station, and the middle of the turret roof had an armored ventilator. Many of these turrets had a weak spot in the armor due to an area machined to fit the turret drive. This area was covered with additional armor once the problem was discovered.

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In this shot of a Sherman wrecking yard in Europe, you can see the early 75mm turret with depot or even factory level rebuilds, on these tanks before they were knocked out. They could be M4s or M4A3 tanks that were used in the US for training and refurbished on shipped to the ETO. You can see the split commander’s hatch, though missing the hatch doors on two of them, the full-length gun mantlet, the welded on cheek armor over the weak spot, and the commander’s old-style vane site.

The small rotor shield and lack of telescopic sight were some of the first production line changes, and older tanks were field modified with kits to update them, often only covering half the turret with added armor on the mantlet to protect the new telescopic sight. The new factory full-size rotor shield covered the majority of the turret face with much thicker armor. The next big change was a weak spot in the right side of the casting where a thin spot was made while machining the turret for the gun mount was discovered, and armor was welded on the outside of the turret to thicken it back up. Tanks were retrofitted with this armor in the field, and later the casting was changed to include the thicker armor over the area, eliminating the need for the welded on cheek armor.

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This M4 Composite hull tank in the Philippines has the split style commanders hatch on a 75mm turret with most updates

At some point, while all the above was going on someone decided the pistol port was a weak spot and it had to go. So they started welding them closed at the factory, and then the casting had them removed. Then the men in the field went ape poop, and they put it back in, around the time the ultimate 75mm turret went into production, with the thicker armor cast in, the pistol port back, a new all-around vision cupola for the commander and an oval hatch for the gunner.  This would be the final configuration of the 75mm turret. The tolerances used by US tank factories were close enough turrets cast at one factory could be used at another with no modifications. Many older surplus turrets left over from the tank retriever conversion program were used in later production, with all the updates added, and a hatch cut in for the loader. Due to a shortage of all-around vision cupolas, many 75mm turrets with a loaders hatch ended up with the old split style commander’s hatch.

pistolport inside

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This M4 has split commanders hatch, commanders vane sight, full gun mantlet, and welded up pistol port

When hull production switched over to the 47-degree frontal armor configuration, and they went with the large driver and loaders hatches on the M4, M4A2, and M4A3 production, the 75mm turrets needed modification. The hinge for the larger drivers and co-drivers hatches stuck up higher than the older small hatch hulls, they could interfere with the turret’s rotation, since they barely cleared the bustle was the radio was mounted in the back of the turret. The first solution was to notch the bustle a little, but they also changed the turret casting, raising the whole bustle area and making the top of the turret flatter.

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Clod hopper is an M4A3 75  tank, used by the Marines on Iwo Jima

The turret drive motor was either an electric motor driven hydraulic system or a straight electric motor driven system. The hydraulic system was preferred, but when that system was in short supply the electric system was substituted.  The 75mm turret could rotate 360 degrees in 15 seconds with the power traverse. It had a manual traverse system as well, and elevation was handled through a manual wheel.

For the very best in minute detail on this subject, please check out the Sherman Minutia site. One minor bit of trivia about the original style turret, the D50878, and D78461 castings, the ones produced for the 105 armed tanks were unique, in that they had an extra armored ventilator whole drilled in so another one could be mounted. So the 105mm turrets really are 105mm only. I’m still not sure if there is a 1/35mm Sherman M4 105, or M4A3 105 with the correct turret.

 

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An early T23 turret on an M4A1 76w tank. Not all-around vision cupola for the commander and the split loaders hatch

The T23 Turret: Developed For the Failed T23 program, It Found a New Purpose on The Sherman

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The origin of the T23 turret, the fascinating T23 medium tank. It used a gas generator-powered electric drive system, but unlike the ones the Germans used on the Elephant, it worked.

While the 75mm turret was still in production and being improved, the T23 turret, taken from the failed T23 medium tank project, went onto the Sherman with the M1A1 gun on the big hatch, wet ammo rack hulls. This turret was larger and could fit the 76mm gun with much more comfort than the basic 75mm turret. All T23 turrets had loaders hatches, though early production T23 turrets used the hatch that had been the commanders hatch on older Shermans for the loaders hatch and used the new all-around vision cupola for the commander. This didn’t last long; it was found the narrow area between the two large hatches on the roof was a weak spot. The big loader’s hatch went away and an oval hatch went in.  These turrets had the same traverse speed as the 75mm turret and the same ROF.

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Pn this M4A1 76w tank you can see the commander in the all-around vision cupola, and the split loaders hatch open

The T23 turret came in around 4000 pounds heavier than the 75mm turret. The automotive systems of the Sherman tank were strong enough to support the extra weight without any real change in performance or longevity. The drivetrain didn’t receive any changes at all as far as I can tell, and only the Jumbo tanks got a different gear ratio in the differential. All the extra weight in sandbags, concrete and real armor did shorten the life of the automotive components but not by a significant amount.

All T23 turreted 76mm gun tanks, had wet ammunition storage, as did the Jumbo tanks, but not all large hatch hulls did. The M4 (105), M4 composites, and M4A2 large hatch 75mm tanks all had dry ammo racks.  The T23 Turret would get the smoke mortar, and an extra periscope hole machined in when the split loaders hatch was replaced with the oval hatch.

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T23 turret on an M4A3 with the 14th AD
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Another M4A3 76 tank with T23 turret serving with the 14th AD

Sources: Armored Thunderbolt by Zaloga,  Sherman by Hunnicutt, Ballistics and Gunnery by Bird and Livingston, The Sherman Minutia Site, Son of a Sherman by Stansell and Laughlin, M4 Sherman tank at war by Green, Tanks are a Might Fine Thing by Stout, the Lone Sentry, TM9-731B M4A2, TM9-731G M10A1, TM9-745 GMC M36B2, TM9-748 GMC M36B1, TM9-750M3, TM9-752 M4A3, TM9-754 M4A4, TM9-759 M4A3,  FM17-12 Tank Gunnery, FM17-15 Combat Practice firing, FM17-67 Crew Drill and Service of the Piece M4 Series

#5 Combat Performance: How Well it Killed Stuff.

Combat Performance: It Killed Stuff Pretty damn well.

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A line of Sherman II tanks

When Sherman went into combat in British hands in the North African desert in October of 1942, it was bar none, the best tank in the world. It had a better gun and more armor, along with good or better mobility than all the axis tanks it faced. It wouldn’t have a German peer until the Panzer IV was up-gunned and even then, the best version of the Panzer IV was barely a match for a 75mm armed Sherman and totally outclassed by the later 76mm armed tanks. The Sherman tank was designed, and the design improved to maximize how easy it was to produce, while also improving the reliability, crew fighting efficiency, safety, and comfort. This was fairly unique to U.S. Tank design and can be attributed in many ways to the automotive production experts who came out of Detroit and the US Auto industry.

The basic small hatch Sherman was found to be fine for the job all the way through the invasion of Italy and Normandy. The introduction of the Tiger and Panther as specialized tanks that were rarely seen. In the Tigers case, they were right. It was a rare and more or less useless waste of German resources. The Panther would become much more common after the break out from Normandy, but if you really look at its performance, it was not that great of a threat. In most cases when they met in Europe, the Sherman won. The 75mm M3 Armed Sherman was very well equipped to deal with infantry and AT guns, the main threat they would face, and this was part of why the US Army didn’t want to jump to the available at the time of Normandy, 76mm armed Shermans.

The US Army tried the M1 gun out on the Sherman just about when the Sherman 75 hit production. The Sherman Minutia Site has images and covers the history, as do various books,  the M1 gun fit, but was a tad long, so they just chopped off more than a foot from the barrel. It worked well enough they ordered 1000 Shermans armed with the gun, but then the order was canceled because the turret was too cramped. Later, they would adapt the T23s turret to the Sherman hull for a much better solution to the problem of up gunning the tank.  After the war, the many 75mm Shermans were up-gunned with the M1A2 gun and then given to allies as military aid. A fun way to see a few of these tanks in action is to watch the 70s movie, Kelly’s Heroes, the Shermans in that are all up-gunned 75mm turreted M4A3 tanks.

The Sherman, even the version armed with the 75mm gun, could still deal with the heavier Nazi German tanks, as long as it had room to move around, and knew where it was. Much noise has been made about how it was a death trap after the D-Day landings and the Panther and Tiger tore it up in the bocage. This is a myth. There is pretty good evidence the US Army only faced maybe two or three Tiger I tanks, in Europe, ever. The Panther was more common, but also got roughly handled in just about every battle it faced Shermans in.

The German’s rarely used the Panther in the bocage country because its long gun made it hard to use in the tight quarters and reliability problems were ever-present with this tank. The tank the Sherman faced in US hands was the Panzer IV and various Stug assault guns, neither of which outclassed the Sherman in any real way. But they did have the advantage of being on the defense.

Post-war studies by the US Army showed the Sherman was more effective than German armor at this point. The claims of the Sherman being a death trap were false. Even early Sherman tanks were no more likely to burn than any other tank and the later war wet ammo rack tanks were the safest tanks of the war. German tanks used gasoline and gas was not found to be a major cause of fires in destroyed Shermans, ammo fires were. See the links in the data section for info on this. Most Sherman losses were due to anti-tank guns, infantry AT weapons and mines, and not so much tank on tank action.

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When Operation Cobra was kicked off, the first use of a large hatch hull, wet ammo rack, 76mm armed Shermans took place. The M4A1 76 being the model used first followed by A3 76 tanks within weeks. These tanks were not well received across the board, with some units preferring the 75mm armed tanks because facing armor was rare even then and the 75mm gun was better at taking out anti-tank guns and infantry, and could still deal with any German armor they encountered. Some units welcomed the better anti-tank capability even if it wouldn’t kill a Panther from the front unless at very short range.

By the battle of the bulge, the M4A3E8 and M4A3E2 Jumbo were showing up for combat use. The Jumbo had much thicker armor and were loved by their crews. By the close of the Bulge, German armor would become very rare, but even so more and more 76mm armed Shermans would be issued. By the end of the war, the ratio would be near 50%. The Army also wanted to stop production on the 75mm gunned M4s in 1945, but the USMC and the British still had requirements for the 75mm gun tanks so it stayed in limited production.

There was a bit of a scandal about the Sherman being no good in the press back in the States about the time of the Bulge. The reality was, the Sherman was having its shining moment during that battle and performed very well against German armor that was supposedly better. Bad movies aside, the Sherman more than held its own in the Battle of the Bulge, also known as the Ardennes Offensive. This is covered in Steven Zaloga’s Armored Thunderbolt, in much more detail.

By the time the next generation replacement showed up, the M26, the war was all but over, and only a handful would see combat. In many ways, the M26 was inferior to the M4. Due to its slightly shortened development and testing time, it had a few reliability problems. It was still so reliable that it would have put any German tank to shame though. The motor, though stressed more in the M26, was the GAA, and it was solid and reliable. The very early tanks had some transmission issues, that were resolved, and some minor things like bracing the final drive housings and changing the drive sprocket configuration were the only major changes. It was never as reliable as the Sherman, but it was close enough to be adopted for use by the Army and Marines.

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M4A1 tanks coming off a floating doc from an LST. the LST does not get enough credit for being a technological marvel of its time and something Nazi Germany had no ability to produce.♦
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M4A2 76W lend-lease tank in Soviet use, note the ever-present log on the Soviet Sherman, the infantryman is kneeling on it. I built a dragon M4A2 76w like this once in 1/35 scale. The Soviet crews were sad to see their tanks destroyed per the lend-lease agreement at the end of the war. When watching the US and Brit freighter crews dumping the tanks in the ocean instead of taking them home, they stopped giving them back. They turned them into tractors by removing the guns and turret.♦

This M4A1 seems to be under fire, and has a lot of junk on the back. Notice the soldier looking at the camera.
M4 composite hull under fire in the Philippines, and just look at all the stuff they have packed onto the back of the tank, and note how it’s all tied down. ♦
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An M4A1 76w and an M4 of the 3rd AD Shermans in action in Belgium, 1944. It looks like the M4A1 76 has an air recognition panel on the rear deck. 
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An M4 with the 3rd Armored Division, near Stolberg Germany, 1944. The tank appears to have all the “quick fix” upgrades.♦
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Looking for a sniper, an M4A3 76w, and an M4A3E8.♦
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A late production small hatch M4A1 75 passing knocked out Nazi PIV tanks. ♦
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Another small hatch M4A1 75 passing a knocked out Nazi PIV, this M4A1 has what looks like an extra steel plate attached to the front of the hull. ♦

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Sources: Armored Thunderbolt by Zaloga, Yeide’s TD and two separate tank battalion books, Sherman by Hunnicutt, Combat Lessons, The Rank and file, what they do and how they are doing it 1-7, and 9.  Archive Awareness, Oscar Gilbert’s, Marine Tank Battles in the Pacific, WWII Armor, Ballistics and Gunnery by Bird and Livingston,  M4 Sherman tank at war by Green, the Lone Sentry, the data in the data section

#3 The Sherman Variants: The Design Matures

The Sherman Variants: So Many Shermans, so Confusing! Updated 02/21

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M4A4’s in the Desert Training Center in California. These tanks would be overhauled and shipped to the British in 1944. 

First off, Americans referred to the Sherman as the M4, or M4 Medium, or Medium, the Sherman name was not commonly used until post-WWII. The British came up with the name for the M4 and referred to it with their own designation system that is covered in more detail later. They also named the Lee and Stuart, and at some point, the US Army just stuck with the naming scheme. The full story behind this is still a minor mystery, with US wartime documents confirming the ‘general’ names were at least used on paper by the US Army during the war.

Now let’s cover the factory production versions of the Sherman. Also, keep in mind; it is very hard to define just how a Sherman may be configured without really knowing where and when it was produced. In some rare cases, large hatch hull, 75mm armed Shermans got produced with normal ammo racks, when the norm for large hatch hull tanks was wet ammo racks.

Then you have post-war rebuilds, where the Army swapped 76 turrets onto 75mm M4A3 HVSS hulls during depot level rebuilds.  It would not be impossible for a field repair depot to swap a turret, from one knocked out tank, onto the hull of another, making an oddball. You also have to take into account post-war monuments are sometimes Frankenstein tanks, in one case with a T23 turret on a small hatch hull.  You can also run into a Frankenstein tank in museums or post-war civilian restorations. In many cases museum tanks are old range relics that need restoration, in some cases, the tank was in decent shape and a cosmetic restoration can easily be done. For the civilian tanker, who wants a running Sherman, also has to get them from a gunnery range, then, the long process of rebuilding the tank can start. I link to a few places that cover restorations, and these guys do amazing work, taking tanks that you could never imagine running or looking like a tank again, and bringing them back to life. We are talking about tanks used as range targets for decades, in some cases, the powertrain in these tanks survived, the powertrain is the transmission, differential, and final drives.

The nice thing about a tank, as far as WWII collectible vehicles go, say compared to an Airplane, like a P-51 or even SNJ, is tanks won’t break down and kill you by falling out of the sky. If you make a big error in a tank, at worst, you’re going to take out a building, flop it on its side, or sink it in deep mud or something, all not really life-threatening.  Once you have the tank, running it is going to be a lot cheaper than a vintage aircraft as well.  The other nice thing is if you’re handy, you can work on it yourself, without having to get a certified aircraft mechanic to sign off on all your work.  You do need a hell of a lot of heavy equipment to really work on a tank though, but you don’t have annuals and hanger rental costs! This may be why the hobby of owning a tank is becoming more popular in the United States!

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M4 DV early Sherman tank. Because the M4 started production after the M4A1 and M4A2, and M4A4 it started production with cast differential cover, and heavy-duty suspension, but still had DV ports.

M4 Sherman: First in Name, 4th Into Production. 

Click the link above to go to the page dedicated to the M4.

These tanks used the same R975 motor as the M3 and M3A1. The vast majority of the bugs in this automotive system were worked out before the M4 even started production. This really helped give the Sherman its reputation for reliability and ease of repair. The M4 had a welded hull with a cast turret mounting the M3, 75mm gun. Early variants had three hull machine guns, and two, turret-mounted machine guns. The hull guns were all M1919A4.30 caliber machine guns, two fixed, and one mounted in a ball mount for the co-driver’s use. The fixed guns were deleted from production very rapidly. The turret armament remained unchanged for the whole production run: Using the M3 75mm gun with the M1919A4 coaxial machine gun and M2 .50 caliber mounted on the roof. The turret would be the same turret used on all early Shermans and would be interchangeable on all production Shermans. This version was not produced with the later improved T23 turret but did get some large hatch hulls in special variants.

M4105W
M4 105, this tank does not have the factory-installed front sprockets

There were two variants of the M4 to be built with the large hatch hull. The first, the M4 (105) was a large hatch hull mated to the 105mm howitzer, on the M52 mount, in the standard 75mm turret. These hulls did not have wet ammo racks or gyro stabilizers, and the 105mm turrets had an extra armored ventilator, the only turrets to have them. The M4 (105) gun tanks had a special mantlet, with four large screws in the face, unique to 105 tanks. Production started in February of 44, and continued well into 45, with late production M4 (105) tanks getting HVSS suspension. These tanks were used as replacements for the M7 Priest in tank units and spent most of their time being used as indirect fire support, like the M7 they replaced. These tanks also had exhaust deflecting vents installed in the back to help reduce dust from being stirred up.

M4Composite
M4 composite hull, small hatch hull, late 75mm turret with loaders hatch. These tanks get confused for M4A1s. 

One other variant of the M4 to get the large hatch hull(100 or so small hatch casting were made as well) was the M4 ‘hybrid’, this hull was welded, but used a large casting very similar to the front of the M4A1 on the front of the hull. It was found that most of the welding hours building the welded hull tanks were spent on the glacis plate. They figured out by using one large casting, incorporating the hatches and bow gun would save on welding time and labor costs.

These M4 hybrids were used by the British to make Ic Fireflies. They liked the 75mm turret these tanks came with since many already had a loaders hatch, this saved them time on the conversion since they didn’t have to cut one. Most of the M4 composite tanks were shipped to Europe or the Pacific, making survivors rare.

The M4 along with the M4A1 was the preferred US Army version of the Sherman until the acceptance of the M4A3. This tank was made in five factories from July of 42 to March of 45, 7584 produced. As far as the US Army was concerned, the M4 and M4A1 were interchangeable.

M4A1 Sherman: First Into Production, And When It Did Go, It Was The Most Advanced Tank In The World.

Click the link above for a dedicated page on the M4A1

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Early M4A1 Sherman from the 9th Queen’s Royal Lancers,  gathered up just before the start of Operation Lightfoot, the second battle of El Alamein. The photo was taken in late October 1942  and at this time the Sherman M4A1 was a cutting edge tank. 
M4_Sherman
M4A1 76 w, much like the type that would be used in Operation Cobra, beautifully restored.

This was virtually the same tank as the M4, with the same motor and automotive systems and armament. The manual for the tank was even shared between the M4 and M4A1.  The key difference was the cast upper hull. This huge upper hull casting was one piece. This was a very hard thing to do with casting technology at the time, and something the Germans could not have reproduced, they lacked the advanced technology, and facilities needed to do so. Everything from hatches to wheels, and turrets, and guns were interchangeable with the M4 and other Sherman models. This version saw production longer than any other hull type. It also saw all the upgrades like the improved large hatch hull with wet ammo racks, the T23 turret with 76mm gun, and the HVSS suspension system. It was 30 of these M4A1 76 HVSS tanks that were the last Shermans ever produced. The M4A1 was also the first to see combat use with the improved M1 gun and T23 turret during operation Cobra. These tanks would also be the basis for the Israeli M51 Sherman. Three factories produced 9527 M4A1s with all turret types from Feb 42 to July of 45.

The US Marines used one battalion of these tanks on the Cape Gloucester campaign, all small hatch M4A1 75 tanks. This was the only use of this type by the U.S. Marines.

For more information on the M4A1 76w tanks, click here. 

M4A2 Sherman: The Second Sherman Into Production!

Click the link above for a dedicated page to the M4A2

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Mid-production small hatch M4A2, courtesy of the Sherman Minutia site.
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A late production M4A2 76w, probably produced by Fisher, in Soviet use.

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This version of the Sherman used a welded hull nearly identical to the M4, but with a pair of vented armored grates on the rear hull deck. The M4A2 tanks used the GM 6046 twin diesel. This version was produced with all the improvements the other types got, like the large hatch hull with wet ammo racks, the T23 turret with an improved M1 gun, and HVSS suspension. This version would see very limited combat in US hands, most being shipped to Russia with a few early hulls going to the Brits and USMC. This was the preferred version for Soviet lend-lease deliveries since the USSR was using all diesel tanks. It was produced in six factories with 10,968 of all turret types produced from April of 42 to July 45.

M4A2, M10, M36B2 clutch lockout unit

A little trivia about this version, the Sherman used in the movie Fury, was actually a late production M4A2 76 HVSS tank. The only way you can tell a late A2 from a late A3 is by the size of the armored grills on the back deck. They did a great job of hiding this area in the movie.

The Marines operated a lot of small hatch M4A2 and a fairly large number of large hatch M4A2 tanks until the supply of 75mm armed versions dried up in late 1944. Then they switched over to large hatch M4A3 75w tanks, but there were some A2 holdouts amongst the six battalions.

m4a2 early side M4A2 early early bogies small gun shield M4A2 early production, early bogies

For more information on the M4A2 76w tanks, click here.

M4A3 Sherman: The Best Version Of The Sherman, Both in 75mm and 76mm

For more information on the M4A3 75 click the link above, for more info on the M4A3 76w tanks, click this link. 

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Large hatch M4A3 75w
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M4A3 76w HVSS tank, near Bastogne during the battle of the bulge. The Tank is with the 35th Tank Battalion, 4th AD. The photo was taken January 8th, 1945

This would be the base for what would be the final Sherman in US Army use, seeing action all the way out to the Korean War in US Army hands. This tank had a welded hull just like the M4, A2, and A4, but used a new motor. The Ford GAA V8, this motor took some time for its bugs to be worked out, so unlike say, the Nazi Germans, the US Army didn’t use it until it was ready for serious production. When it was, it became the preferred US Army version of the tank in both the 75mm and 76mm armed tanks. It would see all the improvements, and be the first hull type to take the HVSS suspension system into combat for the US Army. The M4A3E8 or M4A3 tank with the T23 turret and HVSS suspension bolted on would be the final and ultimate US Army Sherman. It would be produced in three factories with all turret types, 12,596 built-in total between June 42 and June of 45.

M4A3 instrament panel, late
M4A3 76w Instrument Panel

After WWII when the Army wanted to standardize on one Sherman type, any M4A3 large hatch hull they could find would have a T23 turret and HVSS suspension installed on it. The Army was so thorough in these conversions no M4A3 large hatch 75mm gun tanks are known to have survived with the original turrets installed.  Any M4A1 HVSS 76 and M4A2 HVSS 76 tanks in Army inventory would have been robbed of their suspensions and turrets so they could be installed on M4A3 large hatch hulls.

M4AE2-SHERMAN-JUMBO
M4A3E2 Jumbo

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M4A3E2 Jumbo

The M4A3E2 Jumbo: Fishers Fat and Special Baby!

FTA was the sole producer of one very special variant of the Sherman, the M4A3E2 Jumbo. This version of the Sherman was the assault Sherman, though not expressly designed for it, was manufactured to be able to lead a column up a road and take a few hits from German AT guns or tanks so they could be spotted without having to sacrifice the tank. It had a lot of extra armor, and could take a lot of hits before being knocked out, but was still not impervious to German AT gunfire. Only 254 of these tanks were produced, and all but four were shipped to Europe for use by the US Army. They were all armed with the M3 75mm gun. There was a surplus of M1A1 76mm guns in Europe due to an aborted program to rearm 75mm Sherman tanks with the guns. Many of the Jumbo’s ended up with these guns, but none were ever factory installed.

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The tank was no different in automotive components from the M4A3 tanks, with the sole difference being the slightly lower final drive gear ratio, going from a 2.84:1 ratio in the base Shermans to 3.36:1 on the Jumbos. This reduced the top speed slightly but helped the tank get all the extra armor moving. The Jumbos were well-liked by their crews and in great demand; no more were built, the only batch being produced from May to July of 1944.   Had the invasion of Japan been needed, a special Jumbo with a larger turret that included a flamethrower was considered, but we all know how that story ended.

. . .

The M4A3 (75)w and later 105 was issued to the Marines when the M4A2 75mm tanks went out of production. These would all have been large hatch M4A3 75w tanks, and they may have gotten some with HVSS.

M4A3-Sherman-105mm-Dozer-latrun-1

M4A4 Sherman: The Sherman No One Wanted At First, But In The End Was A Very Important Model,  At Least To The British.

Click the link above for a dedicated page on the M4A4.

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M4A4 being used by the French

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M4A4OTHERSIDE M4A4 SIDE M4A4 rear M4A4 DV M4A4 OFSET m4a4 FRONT SIDE

This tank is the oddball of Sherman tanks. It had a welded hull and used the A-57 multibank motor. A tank motor made from combining five car motors on one crankcase. As complicated as this sounds, it was produced in large numbers and was reliable enough to see combat use, though not in American hands in most cases. In US use they tried to limit it to stateside training duty. The Brits found it more reliable than their native power plants and liked it just fine. The A4 version never got the improved large hatch hull or T23 turret with the M1 gun. Most were shipped to the Brits via lend-lease and many were turned into Vc Fireflies, making it the most common Firefly type. The US Marines operating these tanks in the states as training tanks, 22 of them for two months before they were replaced by M4A2s. This tank had a longer hull, like its Lee cousin to accommodate the big A-57 motor. It was the first Sherman version to go out of production. It was produced in one factory (CDA) from July of 42 to November of 43 with 7499 built.

chrysler-a57-multibank-installation
The massive A57 motor being installed at CDA

The A4 has the honor of being the heaviest and largest standard Sherman. The larger hull to accommodate the A57 motor, and the motor itself added weight. The British used these tanks extensively in combat. These tanks show up in British test reports as well, often pitted against tanks like the Cromwell, in reliability or other tests, and usually coming out ahead. Anyone who has ever changed the spark plugs on their car should really be able to appreciate how hard a motor made by tying five six cylinder automobile engines together, on one crank would be. It is easy to identify an A4 from the side, there’s a bulge on the engine deck just behind the turret, and a bulge in the belly in the same place, both to house a huge cooling fan. The bogie assemblies are spaced further apart, this is very obvious compared to the rest of the Sherman models, and also required a longer set of tracks. These longer tracks spread the added weight out, so it had no effect on flotation.

M4A4 small hatch storage
M4A4 early ammo layout. This would be the same ammo layout on all early tanks before the armor was added to the hull sponson ammo racks and the ready ammo around the turret basket base was removed

It turns out this version of the Sherman served with more nations than any other version! These include Britain, Canada, South Africa, New Zealand, Czechoslovakia, India, China and the USA, all used this tank in combat at some point. I find it very interesting the most complicated Sherman saw such widespread use, and still earned a reputation for reliability second to none. The majority of the British Shermans on D-Day were this model as well.

For a tank the US Army didn’t want, it had an excellent combat record, with the nations that got stuck with it.  The M4A4 is one of the rarest Shermans to find running with its original motor. The A57 would be very troublesome to keep running for a civilian hobbyist, and I have my doubts about how easy it is to get Chrysler inline-six parts in Europe. Few M4A4’s remained in the United States since the ones used in training were refurbished by Chrysler and then shipped off to the UK for conversion to Fireflies.

. . .

All Sherman variants share a lot of details and most spare parts interchange. Only the motors really call for different parts. All early Sherman tanks had 51mm of armor at 56 degrees on the front hull, and 76mm on the front of the turret. The 56-degree hulls are called small hatch hulls because the driver and co-driver had small hatches that forced them to twist sideways to get in and out. They also started out with direct vision ports along with periscopes for crew vision. Even the cast tanks matched these specs and the hatches from a cast tank could be used on a welded tank.  These early hulls had some of the ammo racks in the sponsons above the tracks. Not a great place for ammo, but not an uncommon one for it either. As they improved the hull, they added plates over the direct vision ports and eventually removed them from the castings. Large plates were eventually welded over the ammo racks on the sides, and this extra armor was eventually just added to the casting on the cast hulls. It’s safe to say no small hatch tanks were factory produced with a 76mm gun or improved T23 turret.

The major hull change came when they upgraded the drivers and co-drivers hatch making them bigger. They also thickened the front armor to 64mm but reduced the slope to 47 degrees to fit the new driver’s hatches.  The M4 (hybrid and 105 only), M4A1, A2, and A3 were produced with these improved large hatch hulls. Many of these improved large hull tanks had the original 75mm gun and turret. Even the M4A3 with HVSS suspension was produced with the 75mm gun and turret. Most of the large hatch production was with the new and improved T23 turret.  These larger hatch hulls would still accept the majority of the spares the older hulls used and the lower hull remained largely unchanged and would accept all the suspension types. Any large hatch M4A3 hull was likely converted to an M4A3 76 HVSS post-WWII.

Through the whole production run, minor details were changed. The suspension saw many different versions before the final HVSS type was produced. The track types also changed and there were many variants made of rubber and steel or steel. There were even at least six different types of road wheel! There are so many minor detail changes, the scope is too big to cover in this post, needless to say, the only other tank I know of with so many minor changes over the production run was the Tiger, and in the Tigers case, it’s just sad, with so few produced, it means almost no two tigers were the same. This was not the case for the Shermans and the changes did not slow production down at all and in many cases were just different because a particular part, like an antenna mount, or driver’s hood, could have been sourced from a different sub-contractor, and the parts may look different but would function exactly the same. Tiger parts are not good at interchanging without modification, and a crew of craftsmen to custom fit them. The changes made to the Sherman were either to incorporate better parts or to use a locally made substitute part for one in short supply, so making their own version allowed them to continue production without a slowdown.

To really get a handle on these differences between Sherman models there are two really great sources.

This is the easy, way: Sherman Minutia site a great site that really covers the minor detail changes on the Sherman tank very well.  You can spend hours reading it and looking over the pictures. It explains little of the combat history of the Sherman but covers the minor changes on the vehicles themselves very well. You can spend hours on this site learning about minor Sherman details. It is also a primary source for this post.

Another great way is to get a copy of Son of a Sherman volume one, The Sherman design and Development by Patrick Stansell and Kurt Laughlin. This book is a must-have for the Sherman plastic modeler or true enthusiast. It is filled with the tiny detail changes that took place on the Sherman production lines from start to finish. They cover everything from lifting eyes to ventilators, casting numbers, to the most minor changes to the turrets. Get it now before it goes out of print and the price skyrockets. I liked it so much I bought two!

The turret saw the continual change as well but remained basically the same. The 75mm gun never changed but its mount and sighting system did. The turret lost the pistol port and then gained it back. It gained a rotor shield over time and an extra hatch. All these detail changes are covered on the site above and in the Son of a Sherman book. The important thing to note was the tank saw continual improvement to an already reliable, and easy to produce design. The Sherman was easy to produce for an industrial nation like the USA, but beyond Nazi Germany’s technical capabilities for several reasons, like large casting and the gun stabilization system, or even multiple reliable motors to power the tens of thousands of tanks made.

In the basics section, I’m only going to cover one more thing. The Sherman tank was not as blind as the tanks it faced. The M4 series, from the first production tank to the final Sherman that rolled off any of the production lines, were covered in periscopes or viewports for the crew. The gunner had a wide-angle periscope that had incorporated the site for the main gun, and they very quickly added a telescopic sight to go with it. The commander had a large rotating periscope in his rotating copula. The loader had a rotating periscope and the driver and co-driver had two, one in their hatch, and another mounted in the hull right in front of them once the DV ports were deleted (non-rotating). The later version added a direct vision cupola and a periscope for the loader in his new hatch. All these periscopes could be lowered and the port closed, and if damage easily and quickly replaced from inside the tank. All this gave the Sherman an advantage in spotting things outside the tank; they were still blind, just not as blind as most of the tanks they would face. Finding an AT gun in a bush could be very challenging for any tank, and infantry, if not scared off by the presence of a tank in the first place, can sneak up on one pretty easily. More ways to see out of the tank was the only thing to help with this. That, and well-trained infantry, who stay with the tank.

This was a big advantage when it saw combat and throughout the tank’s career, it was always one of the best if not the best tank of the war. It was reliable, the crew had a good chance of spotting enemies before other tank crews, the gun was stabilized, fast firing, and accurate. It was as good or better than most of the tanks it faced, even the larger German tanks. These tanks were largely failures, with only long debunked Nazi propaganda propping up their war record. The Sherman has the opposite problem.

Smiling_British_Soldiers_in_M4_Sherman_Tank_1943

Sources: Armored Thunderbolt by Zaloga, Sherman by Hunnicutt, Combat Lessons, Son of a Sherman by Stansell and Laughlin,  M4 Sherman tank at war by Green, Tanks are a Might Fine Thing by Stout, TM9-752, TM9-754, TM9-759, TM9-731B, TM9-731A