US Armor

No. GMC = Gun Motor Carriage = M18, M10, and M36. HMC = Howitzer Motor Carriage = M7 and M8.

 

The M10 tank destroyer was a United States tank destroyer of World War II based on the chassis of the M4 Sherman tank fitted with the 3-inch (76.2 mm) M7 gun. Formally 3-inch Gun Motor Carriage, M10, it was numerically the most important U.S. tank destroyer of World War II and combined a nearly all-sloped armor adaptation of the Sherman hull and drive-train, with a reasonably potent anti-tank weapon emplaced within an open-topped, 360º rotation turret mount for its main armament, establishing the American style of World War II "tank destroyer"-designation, fully tracked ordnance platform. This was quite unlike the previous M3 GMC, whose gun was capable of only limited traverse, as essentially an adaptation of a self-propelled artillery platform. Despite the introduction of more-powerful types as replacements, it remained in service until the end of the war, and its chassis was later reused with a new turret to create the M36 Jackson, which used a 90mm gun instead of the 76.2mm gun.

The 3-inch Gun Motor Carriage T35 was the prototype of the M10. It was equipped with a 3-inch (76.2 mm) gun in a sloped, circular, open-topped turret, developed from the Heavy tank T1/M6 turret, and mounted on an early-production Medium tank M4A2 hull.

The M18 Hellcat (officially designated the 76-mm Gun Motor Carriage M18 or M18 GMC for short) was an American tank destroyer of World War II, used in the Italian and European theaters, and in the Korean War. . It was the fastest armored vehicle in the American defense inventory of the 20th century, until the turbo shaft-powered M1 Abrams heavy main battle tank appeared decades later.

Changes to the specification mean that the first pilot - the T49 GMC - was built with the British (57 mm) QF 6-pounder gun instead of the 37 mm and torsion suspension instead of Christie. It was tested in 1942 but the army wanted a heavier gun - the same 75 mm gun M3 as used on the M4 Sherman medium tank. The T49 project was cancelled and the second pilot was built with the 75 mm gun as the T67 GMC. This met approval but in early 1943 the army requested a more powerful gun - the 76 mm gun M1 under development for the Sherman. Six pilot models - as the T70 GMC - were built with this gun. The trials of these led to a new turret and changes to the hull front but the design was otherwise accepted for production which began in mid-1943.

 

A couple of quick notes.

The 75mm M3 GMC was never intended as a tank destroyer and actually preceded the creation of the Tank Destroyers. Originally, it was Major Robert Icks extemporaneous design intended to get the venerable 75mm M1897 Gun into a self propelled mount. It was designated the T12 SPM (self-propelled mount) and the first 50 went to the Philippines. About the same time, the remaining 36 of the initial production run were assigned to the "Tank Attacker" units created for the Carolina Maneuvers in November 1941, which resulted in the creation of the Tank Destroyers. They then became training vehicles, but otherwise were intended to equip the Infantry Regiment Cannon Company.

The M10 GMC did not use a turret developed from the Heavy Tank T1, it used the 3-inch Gun M7 developed for the Heavy Tank T1.

The M1 Abrams MBT (heavy main battle tank is an oxymoron) uses a gas-turbine engine, not a "turbo shaft-powered" engine.

 

Almost 100,000 total tanks of all types and GMC. That's a pretty incredible figure considering the time frame.

 

One company of the 899th actually reached the battlefield at Kasserine Pass - the actual battle, not the campaign - just as the defenses collapsed. It was not "in action", but it was there.

 

The 776th TD Bn received their M-10s in November 1942 while they were still at Fort Hood. The following is from the unit history:

 

The 601st and 805th used the half-truck GMC M3 in the March 23, 1943 battle when the M10s were first becoming available. Seems odd.

 

Not all of the TD units got the M-10 at the same time. I believe the 776th was one of the first TD units to get the M-10s. They were also one of the first to get the M-36 before the left Italy for Southern France.

 

In the book "The 50th anniversary of the Second World War" they have a picture of an M10 tank destroyer in the Tunisia chapter, stating it was North-West of the Tunisian Front, so the US troops had them in North Africa.

 

Of course. Read above. Both the 776th and 899th TD battalions had the M10 GMC in Tunisia.

 

FWIW, the pic I used for my avatar is of a 776th M-10 in Tunisia.

 

That's the same picture in the book I have

 

Forgot where I was reading this but read somewhere at first shermans did not support infantry they didn't work together, went ahead of infantry and got destroyed. Then TD were assigned to TD tasks only and shermans were to follow behind and support infantry. Later in the war In Europe TDs were assigned to support infantry, although I never understood why.

 

No. I don't know what you're reading, but my best advice is stop reading it. Its nonsense.

A "tank" was an infantry support weapon, which could also assume some of the traditional roles of cavalry. The U.S. Army acknowledged that fact by creating separate tank battalions to support infantry divisions while the tanks in armored divisions did primarily the penetration and exploitation role of cavalry. However, combined arms - whether it is infantry supported by armor or armor supported by infantry - requires close coordination. Early on, too many theorists - German. Soviet, British, and American - believed in the "tank charge" where tanks would rush a position and overawe the enemy. It only worked so long as antitank defenses were weak or uncoordinated.

Tank Destroyers were simply intended as the highly mobile heavy guns, which would defeat enemy massed armor attacks. They were attached to both armor and infantry formations for the same purpose.

 

You failed to point out the nonsense.. Just because the sherman was supposed to support infantry, at first that's not how they used them. Training in the states was a lot different then the real stuff my friend. Soldiers just didn't know what they were up against. There are many books that mention the lack of mutual support between infantry and tanks, but it changed later on in the war as they smartened up.

 

Some of the nonsense is that is exactly how tanks were used. If you like I can refer you to some of the separate tank battalion AAR's from Italy and NWE. Or you could try Harry Yeide's The Infantry's Armor or Steel Victory. Or Steve Zaloga's series.

The other nonsense isn't that the training in the US was unrealistic, but that it didn't exist at all for the infantry and separate tank battalions. If you want to look at failure, it would be the failure to train and exercise infantry divisions with separate tank battalions in the US prior to deployment. For the divisions and battalions deployed for NEPTUNE it was exacerbated by the fact that none of the training in England for the invasion did so either. In the event, the problem was not "how they used them", but the lack of contact, coordination, and understanding between the infantry and tankers, which caused many initial problems. That is why you see most of the tank battalions were eventually associated with one division. The thing is, you don't see that with the armored divisions. They regularly trained and exercised with infantry and tanks and did not have nearly the problems.

Then there is the nonsense about only TDs were assigned to TD tasks...well, of course. However, if you are talking about antitank defense that is different and integrated the infantry antitank, with the tank destroyers, and tanks (when necessary).

Then there is the problematic nonsense that the source you were reading was apparently unable to explain to you why tank destroyers were assigned to support infantry. They did so because supporting infantry - and tanks - against enemy tanks was what they were intended for.

 

The reason why the infantry gets left behind many times is because they get pinned down by artillery fire. The tanks are relatively immune to artillery fire and they press on.. usually it's a mistake. Tanks draw alot of artillery fire. The trick I suppose is to be close enough to the tanks to receive support from them but far enough away not to get hit by the artillery raining down on them.

 

I think the Sherman gets an unfair bad rap. In terms of its class, a medium, and when it was designed, it was top of the line compared to other contemporary medium tanks, and it could match up, defeat, and withstand battles with other medium tanks of the same time period. It was reliable, maneuverable, fairly quick, and upgrade-able. We also had to think about logistics, quality, transporting across the oceans etc., which is a major factor and should be taken into account. If we had factories in France near the front-line in which tanks could be made and easily moved, do you think we wouldn't have built tanks to match the size, firepower, etc. of the German tanks? I think its more of an achievement to manufacture a quality and dependable tank in the numbers it was produced, and being able to transport it by sea in the numbers it was successfully, and have the success it did on the battlefield.

 

In my opinion the Sherman mostly got its bad reputation because of its weak gun relative to its contemporaries in '44. The M3 75mm had a much lower muzzle velocity than the Kwk 40,42 of the Germans and Soviet 85mm. American tankers were very resentful of this fact and who could blame them as it cost many lives. The effects of the tankers being under gunned could partially be offset by the better guns of the tank destroyers. And the tank destroyers became a part of the tank infantry team.
The problem was supposed to be solved by the new 76mm gun but it wasn't. The testers of the gun used American armor plate for the tests which had different properties than German plate. The consequence being that the 76mm could not penetrate a Panthers front plate from any range and could only penetrate the mantlet from very close range.
This meant that Sherman's had to regularly face tanks that were frontally immune to its weapon... very frustrating indeed.
Overall they had built a great tank. Extremely reliable, repairable, and easy to mass produce. But with guns that were completely overmatched. When the 90mm equipped m36 came it helped alot. But the reputation of the m4 had been sealed and for good reason. Most crews didn't give a hoot how reliable it was, they wanted better guns and never really got them.

Having said that some tank commanders speculated that if the late war Shermans had been available earlier its reputation would have been much better.