Category Archives: T23 Turret

Post #70: Report on the New Weapons Board

Post #70: Report on the New Weapons Board

I downloaded this PDF, Report on The New Weapons Board 1944,  someplace, but since I don’t remember where I hosted it too.  The report documents the feedback the troops gave to the board on the various weapons they demonstrated.

The report was put together in early 44 to document feedback from the troops on current weapons, and proposed improvements, and replacements. There is a good amount of information on the M4 medium tank, and US Armor in general. Most of the combat feedback comes from the fighting in Italy, and North Africa.

The report also sheds an interesting light, and gives evidence for the view that the US Army didn’t consider the improved early Sherman bad, and only wanted it replaced with something much better.  It also gives some interesting insight into the Shermans and what condition they were in when they got to the using units.

Feedback on current equipment and changes.

This is a typical M4 Sherman in Italy, the battalion is being used as an artillery battery, and this is an early production M4 with the M34 gun mount and it probably has a three piece differential as well. It may even have DV ports. These tanks were common in the MTO even into 1944.

The first thing is this to note about the Sherman is the first mention of it is praise for the current models. This quote stands out, “No new type is desired unless the improvement in military characteristics is sufficient to warrant the changes and defects in the present standard tanks are avoided.” 

Another early model M4 in Italy, cheek armor, M34 gun mount and early 3 piece differential.

They did have a list of improvements they did want either done to the Sherman, and to make sure the follow on model, the T20 series incorporated them. 

  1. They wanted a 76mm gun like the 3-inch gun on the M10.  The news of the 76mm M1 series and the new Shermans mounting the gun interested the troops a lot. They brought an M4E6 76mm Sherman.
  2. Improved suspension and tracks. It turns out the rubber block tracks with no chevron were not well liked, and wore out very quick in rock, hilly terrain. The steel chevron blocks with rubber backs were well like and lasted much longer. This feedback is mostly from the ETA, the mountainous and rocky landscape was hard on tanks and even the Sherman had some issues. The complaints about the suspension had more to do with width than durability.
  3.   They wanted armored air cleaners on the M4 and M4A1 tanks.  It turns out the Air cleaners mounted under the overhang on the rear hull of the M4 and M4A1 tanks were prone to damage, and this damage was not expected, and didn’t pick up until Italy so there was a shortage. All other models  had the air cleaners inside the hull. Some units added improvised armor and some was added later in the production runs.
  4. Better ballistic angle around the front of the transmission housing.  The old three part differential is what they are talking about. Most early shermans had this type, and the armor was thinner than the later cast single piece units. There were two cast versions, an early thinner, but still no worse than the three piece unit, and a later improved thicker one. There was a demand for add on armor over this area, but it was never approved.
  5.  More power. Yet, when the M4A3 Ford GAA powered Shermans came online, they did not want to swap them in as replacements, and only wanted whole units who trained on them stateside first to be issued the improved tanks.  The M4A4 and M4A2 were not big enough improvements to switch to those motors. 
  6. Diesel engine. The US Army rejected the GM 6046, claiming it was not as reliable as the R975, but all the nations that did use this motor liked it.
  7.  They wanted better sights and fire control equipment. Many tanks in the MTO and NATO(North African Theater of Operation) had not gotten the M34A1 gun mounts with telescopic sights. The mount for the periscope sight had not seen major improvements, though there were field mods to make it work. The using arm was enthusiastic about the changes in the second gen Shermans fire control, but wanted even more advanced features, like range finders, and improved telescopes, since the current ones shot loose to!

There is also other tank related info.

  • The M3 75mm Gun –  Though well liked for infantry support and deemed to be reliable and durable, the using arms almost universally felt the German 75mm PAK 40 guns were much better anti tank weapons, and a high velocity 76mm gun was in demand.
  • 75mm ammunition – these fixed rounds came unfixed, sometimes even in their travel packaging.  They wanted this fixed. They wanted the WP shells ballistics to match the ballistics of the common HE shell.
  • Large caliber cartridge cases – Steel cases for the 75mm rounds for the M3 gun were well received and proved more durable.  This was not the case for 105mm howitzer rounds.
  • 105mm howitzer armed tanks – This was not a popular notion because the M7 105mm GMC was inaccurate in direct fire when used close assault.  The new weapons board did not agree, and plans for this vehicle were already in motion, and it would be well liked once issued.
  • Tank Officers – they wanted a tanker in the high level headquarters to advise Division and higher level officers the best way to use tanks. AA and Tank destroyer officers were already an accepted part of these HQ staffs.
  • the 17-pdr gun – There was more interest in using this gun in M10s, since the install was much simpler, the Sherman install was complicated, and cramped and the Army was leary.
  • Tank Tracks – They show up again and the plain rubber block tracks could wear out in 250 miles in rock terrain, and lacked good off road traction, and the using arm felt they were only good for training on roads.  The T54E1 steel chevron type was preferred and much more durable, but the T48 rubber chevron would work in the MTO but wore out faster than steel types. The T49 bar cleat was also not good on sidehill terrain. The using arm wanted a wider center guided track in the MTO because the side guided tracks on the Sherman were prone to throwing on irregular and rocky side slopes. Extended end connectors were well received by the using arms.
  • Tank Suspension – Sherman suspension was found to be durable, with few volute springs failing. The biggest problem was the bogie wheels, since the rubber tires had an erratic failure rate, and unlike the spring failures, usually sidelined the tank.
  • Ammunition stowage – They using arms were not interested in changes that reduced the number of ready rounds. The turret ready racks were very popular and crews did not like their removal with the ‘quick fix’ mods. They were willing to risk the higher fire chance, for the faster rate of fire the early storage setup allowed. The crews did not get their way on this one, at least until the M26 went into production.
  • The Radios – They wanted a better radio in the M32 recovery vehicles and better, more comfortable headphones for the armor crews.
  • The M10 GMC – This TD was very popular, and received high praise all around. There usering arm did not require a replacement, just improved M10s. ♠ One thing to note, most M10 GMCs in MTO lacked the Azimuth indicator and range quadrant. Since the M10s get used as artillery a lot in the MTO, they would like replacements to have them.

    M10 in Italy.
  • Replacement gun tubes – The using arms were very annoyed, that all type of gun barrels from machine gun and mortar, to tank and artillery were dispensed at a very miserly rate.  The using arm argued replacement barrels should be bought at the rate that took into consideration how much ammunition for the same weapon was produced.
  • Improved fire control for all relevant vehicles –  They wanted built in range finders, or portable ones supplied. Better periscope and telescope sights and all vehicles that could be used for indirect fire to receive the full suite of tools to perform the task.  Up to reading this, I had never heard that some Shermans did not get these automatically. I’m not sure why some Shermans and TDs didn’t have the Azimuth indicator M19 and elevation quadrant M9. Maybe the crews dumped them to save space, maybe the tanks were rushed and built and approved without them I’ll try and find out. T hey mention 75% of the tanks in England had these items, but less 50% had them in the MTO.  Tank units were much more commonly used for indirect fire in the MTO than they would be in the ETO.
  • Engines –  The R975C-1 was getting around 200 hours before needing replacement. This was fine with the using arm, though they would like 60 to 100 more horsepower.  The R975 needed little maintenance to reach the expected 200 hours and many run much longer.  The lack of liquid cooling system has some advantages.
  • Powertrain –  There was a higher than expected rate of clutch failure in the desert campaigns. The clutch system was also improved on the production like with improved leverage to lower the clutch pedal pressure. Many MTO units did not receive the improved clutches or linkages.  The better clutches lead to better transmission life and better shifting, and even without the improved clutches, transmission life went up in Italy.  The powertrain offered excellent service and generally outlived the engines by several overhauls if not damaged.
  • Crew comfort – the Driver and Co-drivers seats in the Sherman were found to be ok, but higher seat backs were requested along with deeper seat cushions. The Gunners seat was found to be ok, but could use the same improvements as the drivers seats but the Command and Loaders seats were deemed all but useless. These would be improved in the later models of the Sherman and various TDs.  Crews do not use their seatbelts, fearing it complicating bailing out, and more padding inside was not wanted because the crews felt it was a fire hazard.  The M4 and M4A1 tanks were praised for good ventilation. There was also some discussion about the value of turret baskets, and if they were needed at all.
  • Ammo Storage – The early Sherman ready racks in the turret were well liked by the using arms, but they felt the sponson and hull ammo racks were no good and didn’t support the 75mm Shells enough. They would often separate and dump a bunch of gun powder inside the tank making a deadly mess to clean.  The using arm tends to stuff the tank with extra rounds, adding to the shell durability problems. These problems would be addressed in the second gen improved hull tanks.
  • General storage – The current storage space on the Sherman was deemed ok, but better, easier to access bins were requested. They also wanted any storage in the floor to be resistant to getting filled with dirt or water.
  • Machine guns – The bow machine gun see a lot of use, but it’s usefulness would be improved by a sighting system. One was in the works, but not at the point of this report.  The M1919 machine guns, both bow and co-ax were reliable as long as the crew was careful with the ammo. Long road trips could vibrate rounds loose in the belts and cause problems, but under normal conditions this was rarely a problem with well trained crews.  The crews wanted a better adjustment method for matching the co-ax gun to the gunners site, the current one was not very good.  The .50 AA mount was not well liked or considered important. Requests were made for better mount for ground targets.
  • Turret hatches – The current split hatch was deemed ok, but the crews like the looks of the new all around cupola, and were also enthusiastic about a loader’s hatch on the new 76 armed tanks.
  • Armor – There does not seem to be a consensus on how much armor a tank should have by the using arms.  Armored Force troops felt the current level on the Sherman was fine, but wouldn’t mind more as long as it did not negatively affect flotation, maneuverability, and speed. ♠The British generally wanted heavier armor than the US Army.    ♠♠Combat in Italy showed the differential was taking more hits than anything, and another request was made for add-on armor for the area.
  • Sand Shields – The general consensus on these was they were useless in any theatre and needed to be redesigned. They needed to be easier to install, and designed to not trap mud.
  • Flotation – The using arms wanting tanks around 10 pounds per square inch. This was very optimistic, since even the HVSS Shermans came in around 11 PSI, the basic 75 vvss Sherman around 13.  It seems the Germans flooded fields in Sicily and Italy and they retreated, and Shermans got bogged down most of the time.  They offered the suggestion of just stretching the Sherman, since more length would help, and the British M4A4 tanks, the longest production Shermans had no maneuverability issues.
  • Maneuverability –   In the US Army there was a desire across the board for more maneuverability, in tanks. One thing to keep in mind though is the tanks in the MTO were older and most had single anchor steering brakes, the double anchor made the tanks easier to maneuver requiring less lever pressure. The ability to skid turn was not something US troops seemed interested in.
  • Accessories – The troops had a lot of feedback here. ♠ The instruments and gauges in medium tanks were not good quality, if they worked they didn’t work long. Oil pressure gauges fail, and no one worries about the motor until both oil pressure gauges die and a low oil pressure light comes on. This seems to be US feedback, I don’t recall hearing complaints from the Brits about Gauge quality. I wonder if the different tank plants sourced gauges from different companies. ♠♠ The compasses on US tanks would not stay calibrated. This would be a very anoying problem. ♠♠♠ Armor for the air cleaners on the M4 and M4A1 comes up again. ♠♠♠♠ The Auxiliary giving good service, and are well liked, but the using arms would like the area area the fuel tank filler for the Aux motor be waterproofed better.  They also noted replacements were hard to come by.
  • Modifications –  ♠ The jist on this one was, in many cases modifications can be seen by inspecting a vehicle, but in others, access panels or more might have to be removed to check. The using arms proposed a record imprinted a brass plate, attached to the vehicle, listing all the modifications that had been applied. ♠♠ They also wanted to emphasize that they did not want any modifications that would not ‘materially increase  the efficiency of the vehicles’
  • Development – The using  werte curious  about the items in development, and finding out a large organization was working to improve almost everything was a morale booster. There was also interest in the T-20 series and if any test vehicles would be sent over for some congress.

 

Information and feedback on future equipment. 

  • The M4E6 or pre production M4A1 76w –  ♠ This improved version was well liked by everyone who checked it out. The bigger turret was a big hit, though not much bigger, it seemed roomier. ♠♠ The improved fire control gear was very well liked and considered an ‘outstanding improvement’.  The 76mm gun was well liked, and every seemed to agree needed. ♠♠♠ The only real concern was the less effective HE round, but it was hoped they would make a better one.
  • The M18 76mm GMC –  The first and bad impression this vehicle lefts was it had no armor, and seemed very mechanically complicated.  The fire control gear was well liked. When the vehicle was demonstrated, the tracks and unthrowable tracks also got a lot of attention.  No one was sure if the speed would be useful, but the maneuverability was well liked. ♠ The  same story with interest in deployment, not as a replacement vehicle, but fulling trained units from the ZI would be ok. ♠♠ This vehicle was not wanted by M10 units already deployed. Units equipped with it in the ZI then deployed were better received, the M10 was still more popular.  An M10 with a 90mm gun was the prefered replacement.
  • M4A3 75W – Even though the Ford GAA was a big improvement, it was not enough of an improvement take them on as replacement vehicles. They were fine for them to be brought with units already fully trained on them.
  •  The M1 Dozer blade kit – This kit was an instant hit, and would have many uses, including clearing rubble after heavy artillery reduced a strong point.  Currently this has to be done by an un armored bulldozer and casualties were high.  it was hoped they would work well enough to help tanks dig in or SPG prepare a position.  ♠ Through testing, they found this kit  could be installed on any Sherman tank type.

This report goes into detail in the appendixes listing all the items demonstrated, and where they were demonstrated. They also include data on how many of the various items demonstrated were ordered by the various theatres.

I think it’s pretty clear the MTO was a backwater. The general shortage of spare parts in the MTO, and a shortage of personnel to staff the proper echelons of repair and salvage system are also indicators of this. As they got read for the June of 44 landings, the troops in England would be getting top priority and supplies and spares.

There is a lot of info on other weapons like artillery and small arms, not directly Sherman related and therefore, uncovered here. The report is definitely worth a download and re through.  I think it offers a good insight into the thinking involved on not swapping to 76mm armed Shermans before the Normandy landings.

#32 Sunken Shermans: Shermans That The Nazis Sent To The Bottom Of The Sea

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Sunken Shermans: Shermans Now Home to Fish, or That Were Home To Fish

Several cargo ships loaded with Sherman tanks were sunk during the war. A couple of these wrecks have been discovered. The first we’re going to talk about is the SS Empire Heritage, originally named Tafelberg. She was a steam tanker built in 1930. She was 508 feet long and just under 14,000 gross tons. She was built by Armstrong W.G. & Whitworth Co. Ltd. Her captain’s name was James Campbell Jamieson, and she had a 76 man crew and she had 160 people on board. She was reroute from New Your to Liverpool with 16,000 tons of fuel oil and 1900 tons of cargo, including Sherman tanks.

On September 8th 1944 just 15 miles north of Donegal Northern Ireland, she was torpedoed by Nazi Submarine U-482 with the loss of 113 lives. From what I can tell, the wreck was discovered in 2014 and is 220 feet below the sea, just within reach of very technical divers. They took some very interesting pictures.

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M4A1 76w tanks that went down with the SS Empire Heritage
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More shots of the M4A1 76W tanks

 

 

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The next wreck were going to talk about is the SS Thomas Donaldson. She was a 7200 ton Liberty Ship built in 1944 by Bethlehem Fairfield Shipbuilding Corp. Ltd. in Fairfield California, under the command of Robert Headden. She left Loch Ewe, Scotland, as part of Artic Convoy JW-65, on March 11, 1945. The convoy she was a part of had 26 ships and the SS Thomas Donaldson was the only one that didn’t make it to the Russian Port in the Kola Inlet. Late on the afternoon of the 20th, the Nazi U-boat U-968 attacked the convoy. They were just twenty miles south of their destination when the Nazis struck.

The Ship was hit by a single torpedo that took out the ships engine. It also killed three of her crew. The Captain ordered the ship abandoned due to her dangerous cargo, but a small crew including the Captain stayed aboard and tried to save the ship. She was taken under tow, and almost made it in, but sunk short of the port. Only one more crewman died of his injuries and the whole repair crew made it off.

In July of 2014 a Sherman was recovered from the wreck, and they say there are two more down there that can be recovered as well.

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An M4A2 76 W tank recovered from the wreck of SS Thomas Donaldson, sunk on March 20, 1944.

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#3 The Sherman Variants: The Design Matures

The Sherman Variants: So Many Shermans, so Confusing! Updated 4/13

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M4A4’s in desert training center in California.

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 war time 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 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 a restoration, and these guys do amazing work, taking tanks that you could never imaging running or looking like a tank again, and bringing them back to life.

The nice thing about a tank, as far as a WWII collectable vehicle goes, say compared to an Airplane, like a P-51 or even SNJ, is tanks won’t breakdown, 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. 

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-drivers 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.

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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 tank also had exhaust deflecting vents installed in the back to help reduce dust from being stirred up.

 

 

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M4 composite hull, small hatch hull, late 75mm turret with loaders hatch

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 were the preferred US Army version of the Sherman until the introduction 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.

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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
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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 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 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.

M4A2 Sherman: The Second Sherman Into Production!

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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 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 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

 

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

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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 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 Instrament 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.

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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 gun fire. 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 re arm 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 though, the only batch being produced from May to July of 1944.   Had the invasion of Japan been needed, a special Jumbo with larger turret that included a flame thrower was considered, but we all know how that story ended.

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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.

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

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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 crank case. 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 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.

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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.

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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.

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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 into 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 drives hatches 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 version before the final HVSS type was produced. The track types also changed and there were many variants made from 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 to 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 a 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 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 most minor change 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 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 view ports 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 site 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). 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 easy.

This was a big advantage when it saw combat and throughout the tanks 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.

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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