M12 GMC

[PLG]

I'm a new guy on the block and just getting into this fantastic game. I see no reference anywhere to the M12 GMC, self-propelled 155mm gun. I believe this weapon played a rather important part at Aachen. Has this weapon been added in any of the mods?

[Redwolf]

You cannot add new units in mods. Mods are about the textures of existing ones only. You cannot even change the shape.

There are quite some units left out, but I don't think this one is particulary interesting for CMBO as the armor wasn't even protecting the crew completeley, didn't it? A Hummel has at least front and side cover so that it counts as an armored fighting vehicle.

[Scott B]

Originally posted by PLG:

I'm a new guy on the block and just getting into this fantastic game. I see no reference anywhere to the M12 GMC, self-propelled 155mm gun. I believe this weapon played a rather important part at Aachen. Has this weapon been added in any of the mods?

You are correct, there was at least one employed in direct fire at Aachen; unfortunately, it didn't make the cut for CMBO. The M7 Priest is probably your best bet as a substitute; its rounds don't do as much damage as the M12's did, but it has more of them.

Scott

[Michael Emrys]

Originally posted by PLG:

I believe this weapon played a rather important part at Aachen.

I have read that it was also used in busting West Wall bunkers.

Still, its use in CM type firefights is so unlikely as to not warrant its inclusion. Perhaps after the engine rewrite a greater range of weapons types will be included. God knows how we have bleated for the M16...

Michael

[HVAP]

Just imagine the sheer joy of shooting something with the M12 though. I want that and the M16 so badly, just so i can shred those flak wagons. I look forward to it in the next engine rewrite in the not (hopefully) to distant future

[offtaskagain]

Death Traps has couple accounts of it being used as an emergency TD in both Normandy and the Ardennes.

[Redwolf]

So what about the crew compartment? Does it have a front and side armor for the crew, sufficient for operating the gun under smallarms fire?

[Scott B]

Originally posted by redwolf:

So what about the crew compartment? Does it have a front and side armor for the crew, sufficient for operating the gun under smallarms fire?

Missing Lynx M12

Other M12 Photo

Basically, no.

Scott

[PLG]

I thought Death Traps brought out some really interesting points from someone in a position about which very little is written. Some other interesting points, certainly worth discussion, that the writer (a Lt. in maintenance in an armored division) makes are:

1. For those who haven't read the book, the "death trap" is, of course, the Sherman.

2. The writer specifically blames Patton for the late arrival of the Pershing.

3. He claims plunging fire from M7's was one of the best weapons against Panther's and Tiger's. Interesting how this ties in the another thread here regarding .50 cal. strafing fire from fighter bombers and it's effectiveness.

4. For those of us who have argued that those responsible for the adoption of the Sherman should have been shot, the standard response has always been it adaptability to mass production and its reliability override it's obvious shortcomings. This book would suggest that the high percentage of "effectives" was not due to inherent reliability, but to a very large and effective maintenance system.

5. Losses were so high in the "Ronson" that they exceeded the estimates of the army. The tank crew training school (at Ft. Knox, one supposes) was prematurely shut down, resulting in a crew crisis in 1945.

The book does, indeed, make for interesting reading.

Paul

[Marlow]

For the record, I miss the M16 far more than the M12.

Ok, now for the OT stuff

Originally posted by PLG:

4. For those of us who have argued that those responsible for the adoption of the Sherman should have been shot, the standard response has always been it adaptability to mass production and its reliability override it's obvious shortcomings. This book would suggest that the high percentage of "effectives" was not due to inherent reliability, but to a very large and effective maintenance system.

There was nothing wrong with the adoption of the Sherman. It was an excellent design for 1942, when it was fielded. The problem was that it wasn't replaced or significantly upgraded in 1944 when the powers that be knew or should have known that it was outclassed.

The Sherman chassis was itself very adaptable, and formed the basis for countless other American armored vehicles, (the above mentioned M7 among others), and could have resulted in a medium tank that could have gone toe to toe with the Panther and Tiger, had some effort been made. The Firefly is proof of this, as are the M36B1 (90mm gun on a sherman chassis) and the post-war Israeli Sherman varients. A closed topped 90mm gun version of the Sherman was entirely within the techical cababilities of the U.S.

[PLG]

Well, I don't know about an excellent design in 1942. It might have been an adequate design to have in service in 1942, but the bulk of the M4's were built well after 1942 and they were a fundamentally flawed AFV during that period. Aside from inadequate armor, the lack of Christy suspension resulted in too high a tank, making for a tasty target; the main gun was inadequate until the adoption of the 76mm, which was at best marginal. Additionally, the narrow track made for very poor flotation and lagged well behind contemporary AFV's from both Germany and Russia. Sherman's bogged down quite easily and were out-maneuvered in rough or wet terrain by much larger and heavier tanks. They were "death traps."

The M7 Priest was based on the M3 chassis, not on the M4. However, the B1 received numerous updates from the M4, such as bogey wheels, etc.

Paul

[Simon Elwen]

As early as May 1942 the americans had an 88 shipped to the USA for evaluation and the planners at the US War Dept still carried on with the Sherman under the misconception that armour would be chiefly used for exploitation and pursuit. They believed that sacrificing armour for speed would pay off but of course speed in battle means nothing without survivability

[Redwolf]

Originally posted by Marlow:

For the record, I miss the M16 far more than the M12.

Me too.

There was nothing wrong with the adoption of the Sherman. It was an excellent design for 1942, when it was fielded. The problem was that it wasn't replaced or significantly upgraded in 1944 when the powers that be knew or should have known that it was outclassed.

I think there are two points that apply in 1942:

The suspension with bad going in difficult ground and no in-place turn capablity.

It is too high. As good as that is for shipping, the losses in M3 medium tanks should have brougt that lesson home.

The Sherman chassis was itself very adaptable, and formed the basis for countless other American armored vehicles, (the above mentioned M7 among others), and could have resulted in a medium tank that could have gone toe to toe with the Panther and Tiger, had some effort been made. The Firefly is proof of this, as are the M36B1 (90mm gun on a sherman chassis) and the post-war Israeli Sherman varients. A closed topped 90mm gun version of the Sherman was entirely within the techical cababilities of the U.S.

The M7, M10 and M36 have been built on the chassis of the M3 medium tank, not the M4. All these SP guns would have been possible without constructing the Sherman and without retooling the factories for the Sherman.

The post-war 90mm guns are a lot lighter than the WW2 90mm guns. A 90mm Sherman was outside the technical reality of WW2, much progress had been made in the very first years after WW2, but even then the US Shermans were still using the 76mm at the time of Korea.

In my opinion, the real errors were the suspension/chassis of the Sherman (including/plus the height) and especially the lame 76mm gun. It is one thing to ship tanks which are not supposed to fight other tanks with a gun which can't fight tanks. But it is another thing to ship a tank destroyer with a gun which had difficulties with half the enemy fleet (number-wise, not model-wise).

[Marlow]

Originally posted by redwolf:

The M7, M10 and M36 have been built on the chassis of the M3 medium tank, not the M4. All these SP guns would have been possible without constructing the Sherman and without retooling the factories for the Sherman.

Yes, I was wrong about the M7, but one of the M36 varients, the M36B1, was built by dropping a 90mm turret on the M4, and even had the bow machine gun.

The post-war 90mm guns are a lot lighter than the WW2 90mm guns. A 90mm Sherman was outside the technical reality of WW2, much progress had been made in the very first years after WW2, but even then the US Shermans were still using the 76mm at the time of Korea.

The Sherman could have (and did, see above M36B1) carry a 90mm. It would have been a simple thing to add top armor and turn it into a viable medium tank (there were even field addition kits that did provide some top armor for M36s).

[ March 21, 2002, 09:38 PM: Message edited by: Marlow ]

[Tanaka]

Originally posted by Marlow:

... (there were even field addition kits that did provide some top armor for M36s).

Believe me, it was only for grenade bouncing propose

Between it and actually placing, on top of a M4 chassis, a well-planed 90mm gunned enclosed turret there is a big distance

[hank]

To paraphrase a guy over on soc.history.world-war-ii, the typical US infantry division suffered around 200% casualties in the campaign from Normandy to the end of the war. The typical armored division suffered about 100%, with most of them in the amormed infantry portion of the division. Shipping a bigger, better tank means fewer tanks in Europe, and less support for the PBI. It's not a stretch to imagine that means more casualties in the infantry. So, given that we did win, why would we sacrifice the lives of infantrymen, who were having a tough time of it anyway, to save more tankers, who were comparitively safer?

It seems to be a common complaint that the Americans didn't drive around in some sort of land-battleship, but alone among all combatants the Americans had to get all of their armor across an ocean before getting it into battle. This imposes a definite constraint on how you plan your war. Can you get the big tanks into an LST? Oops looks like we have to redesign them too. Too bad the big tanks won't go over the bridges the engineers can lay down. It's much more complicated than merely invoking a bigger tank. Everything the tank touches has to take into account its size.

There's another book floating around out there called "The View From the Turret". It's the history of an independent (read infantry support) tank battalion armed with mostly 75mm Shermans. In it the author makes the standard complaints about how horrible the Sherman was. But the funny thing is that if you add up the number of Shermans knocked out by German armor (note we are excluding AT gun and infantry kills) and compare it with the number of German tanks the battalion knocked out, the lowly Sherman actually had a positive kill ratio. That's not too bad for a unit armed with the wimpiest version of the tank.

I freely admit that incremental improvements to the Sherman could have been done more quickly, but at the strategic level, the Sherman is in a tie with the, equally mediocre, T34 as the best tank of the war.

Oh, and one last swipe at the "Death Traps" guy, he was in the 3rd Armored Division. They had the distinction of having the highest tank loss rate of any American division. So the REMF author was fixing tanks for a bunch of guys that were at best a little over-aggressive considering that they weren't driving around in land-battleships.

[Redwolf]

Nobody doubts that there were some constraints on the US that restricted the way they built their tanks.

I agree that simply shipping a heavier tank would not have been an option.

The problems I cited with chassis/suspension, height and the inadequate TD gun have nothing or few to do with this.

And yes, a roof doesn't rurn a TD into a tank.

[Dirtweasle]

Originally posted by redwolf:

...The problems I cited with chassis/suspension, height and the inadequate TD gun have nothing or few to do with this...

What was the problem with the suspension exactly? My impression is that if nothing else the Sherms had decent suspensions, and with the Easy-8 they had a real good suspension drive combination with very good all around off-road capability.

[Redwolf]

Originally posted by Dirtweasle:

What was the problem with the suspension exactly? My impression is that if nothing else the Sherms had decent suspensions, and with the Easy-8 they had a real good suspension drive combination with very good all around off-road capability.

All spring-based suspensions share the problem that a spring gets softer the more it is charged. On the road that is fine, but in open terrain, when different wheels are at different levels of spring charging, your vehicle tends to be lifted exactly by the springs in those places where you don't want, adding a lot of unwanted vertical movement. This problem is shared with the Christie suspension, but not with the torsion bar mechanism.

Bigger wheels are better than small ones, to distributed ground pressure better. They also add to the lower side hull armor.

Putting pairs of wheels on one suspension mechanism is also a disadvantage, but it is difficult to do otherwise if you want the springs to be on the outside, not hidden as with Christie, because you don't have space for big wheels, but to lower ground pressure you then need more small wheels.

The outside suspension is also easier to damage and easier to repair. In my opinion, a MBT that is supposed to drive through a lot of random fire (as opposed to few targetted big anti-tank rounds), and therefore is built with all that armor the TD doesn't have, I think it is not a clever idea to give the repair aspect preference. A lot of smaller gun rounds or HE shells may damage the suspension and the MBT is supposed to go on a rampage behind enemy lines, where it is difficult to reach it for repairs. For a TD like the M10 I would give repair preference, but not for a MBT.

As said often, the tracks on the Sherman are too narrow, and they couldn't easily place bigger ones because the wheels were not wide enough and coultn't be made wider easily since they were hanging on that one-point spring mechanism.

Finally, the Sherman cannot rotate in place, and the US had plenty of opportunity to see that this is a big advantage at least when battling AT guns, TDs or other tanks before they committed to the Sherman.

The easy-8 mechanism is fine, of course.

[Dirtweasle]

Thanks Redwolf, I understand it now.

[Marlow]

Originally posted by redwolf:

Nobody doubts that there were some constraints on the US that restricted the way they built their tanks.

I agree that simply shipping a heavier tank would not have been an option.

The problems I cited with chassis/suspension, height and the inadequate TD gun have nothing or few to do with this.

And yes, a roof doesn't rurn a TD into a tank.

Oh, and what makes a tank?

Lets see:

adequate armor. M36B1. Roughly the same as the M4 with the exception of no top armor on part of the turret. Yup (again except the turret).

secondary MG armament. M36B1. Bow .30 and AA .50. Yup.

Turret. M36B1. Power turret faster than equivalent axis turret (please, no posts about revving engines). Yup.

Slap 15 to 20 mm of armor, along with the other necessities (hatches, periscope, etc...) and we have a winner.

IIRC, the army was fiddling around with a redesign to uparmor and upgun hte Sherman, but the decision was made to go with the M26 instead. The flawed tank/tank destroyer doctrine, and later the development of the M26, is also the reason that the Sherman was not further upgraded during the war, or prior to Korea, not technological limitations.

The problem is not so much the Sherman, but that U.S. didn't take advantage of what could have been done with it. Combine the best features of a W(+) easy-eight suspension Sherman with either the 17lb gun or the 90mm, and you have maybe not the worlds best tank, but one that certainly could have stood up to the German Panther and Tiger on something approching an equal footing.

[Tanaka]

Originally posted by Marlow:

...The problem is not so much the Sherman, but that U.S. didn't take advantage of what could have been done with it. Combine the best features of a W(+) easy-eight suspension Sherman with either the 17lb gun or the 90mm, and you have maybe not the worlds best tank, but one that certainly could have stood up to the German Panther and Tiger on something approching an equal footing.

As said here earlier, the Sherman is too high... no crew likes to be a good target, even if it has the best armor of the world.

Any one that had/has the opportunity to stand aside a T-34 knows very well what I'm talking about.... that low fat b#%tard sure looks mean

Even a mediocre machine, when well known and employed by its crew has a very good chance of successes... higher then the other way around any way, a good machine on incompetent hands.

The initial US "Sherman" doctrine (lying to tankers) implied at very least in a large bill at late 44 early 45, crew shortage and general M4 discredit.

Of course on those days, the lessons of the Israeli Arab 73 conflict were not around, so a GI was glad just because he didn’t had to walk, a fast reschedule to M4 crew member was at 1st sight more then welcome.

[CombinedArms]

Originally posted by Marlow:

I think Marlow has it basically right. I'd advocate the 17lb gun, which was proven capable to fit into a standard Sherman turret. A slightly uparmored Sherman with the excellent easy-eight suspension and the great 17lb gun, if produced in great numbers, would have been a winner of a tank in WWII terms. Maybe it wouldn't have been a land-battleship but an effective enough tank to do the job-- and probably a realistically achievable weapon in quantity by mid-1944 if everything had gone right.

Consider that the P-51 Mustang was at first a bit of a dud. It had an excellent airframe but the orginal Allison engine of the P-51A gave it poor performance at altitude. It was too short ranged to be an escort and a bit undergunned with four .50 cals that tended to jam. Many wanted to scrap the design and go on to something else, but some people saw it's potential, and gradually, after it was equipped with the British Rolls-Royce Merlin engine (built in the US under license), upgunned to 6 MGs, and given greater range with extra external and internal fuel tanks, it became a war-winning weapon.

As I understand it, the British offered the US the 17lb-er and it was refused. (Later the US wanted them but the Brits couldn't make enough for their own use & said no.) If the US had aggressively pursued the 17lb-er and licensed to build it themselves, and if they'd recognized and dealt with the armor and suspension problems as aggressively as the air force worked to upgrade the P-51, then the US could have had an effective and valuable tank in significant numbers in '44, just as the Air Force did with the P-51D. Maybe not every M4 could have had these characteristics, but enough to make a difference. Even if the armor or suspension couldn't have been improved, a mere clone of the British Firefly, in American hands, would have been a vast improvement over the vanilla Sherman or even the Sherman-76.

I think this was pretty clearly a case of poor decision making based on a faulty doctrine of armored combat that caused the decision makers to ignore telling battlefield evidence that didn't fit their personal theories. These guys weren't able to think outside the box they'd constructed, and as a result, they fielded an obsolete tank. That the Allies managed to win with it anyway is a tribute to the guts and savvy of the tankers and the support they got from other arms, such as the artillery and air force.

[ March 22, 2002, 10:56 PM: Message edited by: CombinedArms ]

[hank]

I'll toss in a couple more comments into a thread that has veered quite wildly away from the M12 GMC.

On the subject of height, the Sherman and the Panther were roughly the same. I don't recall too much wingeing about how the Panther was too tall. The Sherman's height came from the early versions being driven by aircraft radial engines. These are not compact power plants, but were the only thing available at the time. By the time a better, smaller in-line engine was available the US was committed to building lots and lots of Shermans. There was no time cut a foot or two off its height (which would entail shutting down factories to re-tool). Once again we're back to the guys in the tanks wanting more protection vs the guys not getting shot at weighing alternatives and deciding to win the war their way.

On the gun issue, there is no argument that McNair got what was coming to him during Cobra. Up-gunning to something a bit zippier was held back by his devotion to the prewar doctrine.

As far as GI Joe making a bad decision by transferring to armor so he wouldn't have to walk so much, it definitely reduced his chances of being killed. The 200% infantry division casualty rate vs the 100% armor division rate made Joe's choice a pretty good one.

Even though the flawed prewar tank/TD doctrine was tossed out the window after the war, it is still hard to argue that it was a failure. It wasn't the best, but it worked and tank crews were far from having the most dangerous job in combat.

[Redwolf]

Originally posted by hank:

On the subject of height, the Sherman and the Panther were roughly the same. I don't recall too much wingeing about how the Panther was too tall.

Actually there was. Especially for the Jagdpanther. If you look into Spielberger's Jagdpanther book, you will find that the Germans considered giving up the torsion bar suspension (which cause the high height) for the Jagdpanther. They couldn't do it for time and production reasons.