XM-1 General Motors / XM-1 Chrysler Prototypes (1976)

[pieve 3,578]

 

 

XM1 General Motors

General Motors developed a tank, which was very close to meet the Army's requirements. It featured a modern armour design, a powerful FCS and a new diesel engine. From its design, the hull reminds on the German Leopard 2. As there was the delivery of the Leopard 2 prototype hull Nr. 6 to the USA, this might have happened not only by accident. The hull front left side contains the driver’s station. To its right, a smaller fuel cell followed by an ammunition rack is mounted. More fuel cells are placed in the hull rear sides. The driver's seat is a conventional one, which can be raised when driving with open hatch. For steering and acceleration the driver is using a t-bar handle. Gear shifting is done with a control handle at the right side of the driver, giving total control on the gears. The handle allows shifting to set the highest gear that can be used (1 or 2 or 3), where the transmission is shifting automatically in the gears below. It is also possible to set the transmission to full automatic mode, where all four gears are used. In addition the gear ranges "neutral", "reverse" and "pivot" are available. This arrangement gives maximized flexibility to the driver and allows him to select always the best gear range. Beside gear shifting, the transmission was also used for steering and braking.
The hull rear contains the power pack. General Motors selected the AVCR-1360-3 engine, which was developed during the MBT-70 project. The engine had gross power of 1.500HP, but a total of 400HP is used for cooling, power generation and lubrication system. The exhaust gases are mixed with the waste air from the cooling system and exits thru one grill, which deflects it downwards.
General Motors designed the XM1 with a mixed suspension. Of the six large road wheels per hull side the first two and the last are equipped with a hydro-pneumatic suspension modules. The three road wheels in the middle of the suspension system were equipped with torsion bars. This design allowed a better performance and saved weight and volume inside the hull.
The turret of the GM prototype was mounted centered on the hull. The design was focused on maximum protection and certainly inspired by British developments of that time. It was all welded and contained layers of special armour. The frontal plates are sloped to the top and to the sides, which is maximizing the protection.
The M68 main gun is mounted in the middle of the turret and includes a small gun mantlet. As the later Challenger tank, the General Motors XM1 is mounting the gunner's sights on the right side of the turret in a special housing. This arrangement allows a plain turret front and does also not increase the vehicle height.
The tank included an advanced FCS, which delivered a full stabilized field of view for the gunner's main sight. The gunner was equipped with day/night channel and laser range finder. The sight could also be used by the commander, who was able to take over control. There was no separate sight for the TC planned. Beside the mentioned 105mm main gun, the tank was equipped with a 7.62mm coax MG, a second 7.62mm M60 AA-MG for the loader and a remotely controlled 12.7mm AA-MG for the commander. The coax-MG is mounted left of the main gun and operated by the loader. The original design of the tank included a 25mm Bushmaster chaingun on the left turret side. As this requirement was skipped, General Motors redesigned the tank in a way that the space was used for additional ammunition storage for the main gun. The ammunition for the main gun is stored in three different locations. The turret rear contained an ammunition storage for a total of 24 rounds. Additional 13 rounds were stored inside the turret at the loaders position. And finally there is the hull front storage, which contained additional 18 rounds. Total ammunition load for the 105mm gun was 55 rounds.
The General Motors designed XM1 was tested from 1975 to 1976. The tank proved to be very agile and powerful. Its diesel engine did not allow as good acceleration as the turbine powered Chrysler tank. But this was clearly compensated by the better transmission control. The diesel engine was cheaper than the gas turbine, but the FCS from General Motors let the price increase. At the end the decision was made for the new turbine and not for the more powerful tank. Too bad.

Spoiler

The General Motors XMl  prototype is shown in these photographs during the evaluation program.

Test instrumentation has been installed on the turret roof and the gun barrel

 

 

 

XM1 Chrysler

The Chrysler prototype was a mix of high and low tech. On one hand the decision was made to use the AGT1500 gas turbine, on the other hand a low tech FCS was developed.
The tank is featuring a flat, all welded hull, which is raised at the rear. The driver is placed in a nearly horizontal position in the hull front. His station is flanked by fuel cells, which increase the protection against shaped charges. The flat position of the driver allowed it also to design a hull, which is less high than other designs. Unfortunately, this did not result in smaller vehicle. As there was a human loader standing inside the turret, a certain height inside the vehicle had to be achieved. And the only way to achieve this was by adding a higher turret. As a result, mass was moved from the hull up into the turret.
As with the General Motors prototype, the driver has a t-bar control handle for steering and acceleration. Only the drive brake is done via a foot pedal. The shifting control is mounted under the t-bar handle. It allows the selection of several gear levels (low, drive, reverse, neutral), which are all automatic modes. It is not possible to select a gear manually. As seen with the General Motors prototype, this option would have been possible with the X1100 transmission. As the Chrysler tank did not go for this feature, it simply has to be called a “designed waste of mobility”. Manual shifting would have been more powerful, but it would also require more skilled drivers.
The hull rear contains the AGT1500 gas turbine, the X1100 transmission and the air filters. Because of the small volume of the power pack, additional fuel cells could be mounted in the hull rear as well. The turbine is placed lengthwise in the hull with the exhaust grill on the hull rear. The tank featured a tube over torsion bar suspension with seven smaller road wheels, three return rollers and drive sprockets at the rear. For protection purposes, the suspension covered by armoured side skirts.
The turret of the Chrysler XM1 was placed centered on the hull. It was made of welded steel with inlays of composite armour. Only the gun mantlet was cast steel. Because of its sides, which are sloped and nearly reach the outer hull sides, the turret front looked very much like a frustum of a pyramid. All sides were made of plates, which are welded together in different angles. The front plates at each side of the gun mantlet are mounted nearly vertical, but sloped to the sides. The turret front center houses a massive cast gun mantlet, which is not sloped at all. This mantlet created one large ballistic hole. A second one was formed by the gunner's sight, placed at the turret right front within the armour arrangement. The tank was better protected than the M60s in use at that time, but not quite comparable to the General Motors XM1 or the earlier MBT-70.
The turret crew consisted of three men. The loader was standing in the turret left side, gunner and commander were seated in a tandem arrangement to the right of the main gun. Armament consisted of the 105mm main gun, a 7.62mm M240 coaxial machine gun, a M85 .50 cal machine gun over the commander's hatch and a 7.62mm M60 over the loader's hatch. The coax MG is mounted to the right of the main gun and operated either by gunner or commander. Instead of the M240/M60 combination, Chrysler also offered the usage of M85 and XM175. But both did not meet the expectations and were rejected.
The turret of the Chrysler made XM1 proposal was electro-hydraulically driven. The tank incorporated a simplified FCS, which delivered a line of sight, which was only stabilized in the vertical plane. In addition, the tower was stabilized in the horizontal plane. This design was chosen to reduce the costs of the vehicle. The FCS covered the gunner's sight and controls, a ballistic computer including control panel, laser range finder, sensors for cant, elevation and azimuth. The gunner was also equipped with an auxiliary sight. While the main sight was located in a small housing at the right turret front, the auxiliary one was placed within the gun mantlet.
The commander was equipped with an independent sight, mounted on the turret roof in front of the commander's hatch. It was also connected to the gunner's primary sight, which allowed the display of the gunner’s view. By using a small control handle, mounted at the right side, the commander was able to take over control of turret and main gun. In addition the commander had a special sight for his weapon station.
Main armament of the XM1 was the rifled 105mm M68 gun. The ammunition load was 40 rounds, which were stored in the turret rear and outside of the turret ring in the hull rear. The rounds in the turret were stored in a closed compartment with one large blowout panel in the roof.
The XM1 was delivered in 1975 and tested until 1976. The Chrysler made prototype was the fastest accelerating main battle tank the US Army had ever seen. The use of the gas turbine and the new X1100 transmission resulted in a much better driving performance than any other American tank in service at that time. This fact, together with the lower price (compared to the General Motors made tank) and by using some of Chrysler’s political influence, the tank was nominated as winner of the evaluation phase. Chrysler therefore was awarded the contract for the delivery of the XM1 FSED.

 

Spoiler

 

 

 

 

Specifications: XM1 General Motors

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Specifications: XM1 Chrysler

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sources:

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http://www.kampfpanzer.de/vehicles/abrams

https://www.fichier-pdf.fr/2014/03/17/abrams-a-history-of-the-american-mbt/abrams-a-history-of-the-american-mbt.pdf

page(158)

http://www.stardestroyer.net/Armour/EBooks/AbramsDataSheets.pdf

page (301) XM-1 General Motors

page (302) XM-1 Chrysler

 

Edited November 19, 2017 by pieve

[SAUBER_KH7 3,326]

Open for Discussion.

[pieve 3,578]

12 minutes ago, SAUBER_KH7 said:

Open for Discussion.

 

[Stofferberry 1,629]

I would like to see these tanks. What I would really like is to have a Vietnam era part of the game. 

[Necrons31467 14,236]

Oh great, another one of these.....

 

Will this nonsense ever stop?

 

32 minutes ago, Stofferberry said:

I would like to see these tanks. What I would really like is to have a Vietnam era part of the game. 

 

You mean like T-54's, M551's and M48's? yeah, we have those.

Edited March 23, 2017 by Necrons31467

[Stofferberry 1,629]

7 minutes ago, Necrons31467 said:

Oh great, another one of these.....

 

Will this nonsense ever stop?

 

 

You mean like T-54's, M551's and M48's? yeah, we have those.

I don't think understand what I mean by Vietnam eta. I want new br separate from regular br we have now. New maps, tanks, missiles,etc.

[Wilhuff_Tarkin_ 467]

28 minutes ago, Stofferberry said:

I don't think understand what I mean by Vietnam eta. I want new br separate from regular br we have now. New maps, tanks, missiles,etc.

It's not going to happen, lower tiers must be clubbed by higher tiers so the players feel the need for grinding better tanks.

 

39 minutes ago, Necrons31467 said:

Oh great, another one of these.....

 

Will this nonsense ever stop?

Exactly.

 

The fact you slap X in front of an M-1 doesn't suddenly makes it suitable for game. It's Abrams, early model but still.

No just No. Everything from 2nd Gen. but not this.

 

And you forgot to put in the title "To counter overpowerd T-64"

[pieve 3,578]

7 minutes ago, Wilhuff_Tarkin_ said:

The fact you slap X in front of an M-1 doesn't suddenly makes it suitable for game. It's Abrams, early model but still.

No just No. Everything from 2nd Gen. but not this.

 

And you forgot to put in the title "To counter overpowerd T-64"

Oh my god, how XM1 is OP

[Results45 2,200]

Add a BR 11.0/12.0 option to the poll and I'll say yes (aka Tier 6) 

 

Better alternatives:

 

FV4211 Aluminum Chieftain/Vickers Valiant Mk.4:

 

 

XM803 (modified MBT-70; led to XM1)

 

 

AMX-32/40:

 

 

Much of the reputable and official info on XM1/M1 development, armor, and ammo penetration is still classified.

 

If nothing else, can't wait to see the release of Modern Thunder in 2025   

Edited March 24, 2017 by Results45

[BucketOfKnobs 81]

Can you people stop going too modern, this is getting ridiculous, we don't need this, yeah it'd be cool to have modern tanks but they do not belong in WarThunder, stop pushing the devs. This is kind of like the ATGMs all over again, they did not want ATGMs but people pushed them and they did it and now everyone hates ATGMs. People need to stop suggesting this stupid stuff.

[Wilhuff_Tarkin_ 467]

1 hour ago, pieve said:

Oh my god, how XM1 is OP

I did not said it's OP, it's pointless.

No reason to be in game.

[_EQUAI_ 356]

we need to slow down with these we barely have composite armored vehicles (type 87 exception) to even begin to consider something like this, as much as I like this tank its not needed now.

 

[_PabloSniper_ 2,142]

BIG +1   

I would very much like to see a 9.0 generation of tanks.

 

 

[Nope 10,634]

2 hours ago, pieve said:

Oh my god, how XM1 is OP

 

Ridiculous mobility and was supposed to originally stop 115mm APFSDS at less than 800m until the introduction of Burlington exceeded requirements. In particular the CIA rated the KE protection of the M1 Abrams at 400mm for the turret, which has similar LoS compared to the hull composite. Also, by the time the gun was placed on it it was supposed to use M735 APFSDS, which could in theory take out the T-72A frontally.

 

I mean, it's like research is an alien concept nowadays. What's next, we beg the devs to implement the Bulldog and Myrmidon tanks from Battletech to counter the T-72 Ural?

[Baconator100012@psn 929]

That looks sooo fun to drive, i want it!

[Necrons31467 14,236]

'' I like how this tank looks, I have not a single idea of how it might effect game balance but I want it anyways, though I don't know anything about this tank's performance, not in regards to it's armour, it's exact gun performance nor it's exact mobility performance, I still want it, and all of the previously mentioned is probably largely irrelevant in a game that attempts to model vehicles according to their historical counterparts anyways, you see? it's just a game, let's throw anything we like the looks of in there regardless of the consequences and see what works, I mean, why not just turn War Thunder into another terrible Armored Warfare/WoT clone?.... ''

 

And people get mad over the fact that Gaijin doesn't model their game according to what exactly the ''community'' wants, I am so incredibly glad that they ignore crappy suggestions like this one, and hope they will continue to do so.

[IOC_000 924]

UFP that is 900-1100MM effective against KE and Sabot? 120 MM Smoothbore cannon with computer controlled fire and stabilization; along with DU APDSFS? and Modern HEAT-FS?!?!  

 

No; completely and totally no. It won't matter what imaginary BR you put it at; the ammunition is still Classified. The armor is able to sop up anything the current game has; along with chugging along at 50 to 70 MPH and firing. It's a sexy and majestic beast no doubt, however this is flying against some of the biggest cutoffs in the game i'm fine with modern-semi-modern vehicles but this is way too much; WT is still not in a position where the T-64 & 72 could be added; let alone the freaking Abrams. 

 

Also please don't use the Type 87 SPAA as justification; it is an EXCEPTION not the rule. The composite it uses was to offer similar protection with less weight than equivalent amount of RHA; not to make it practically immune to anything but weapons specifically designed to defeat it.......

[Stofferberry 1,629]

9 minutes ago, IOC_000 said:

chugging along at 50 to 70 MPH and firing......

70 mph? Dude you need to calm down. 47-48 mph max.

[IOC_000 924]

5 minutes ago, Stofferberry said:

70 mph? Dude you need to calm down. 47-48 mph max.

 

*Snorts white substance* Wut? Ah ok; still hilariously fast though. 

[Nope 10,634]

17 minutes ago, IOC_000 said:

UFP that is 900-1100MM effective against KE and Sabot? 120 MM Smoothbore cannon with computer controlled fire and stabilization; along with DU APDSFS? and Modern HEAT-FS?!?!  

 

No; completely and totally no. It won't matter what imaginary BR you put it at; the ammunition is still Classified. The armor is able to sop up anything the current game has; along with chugging along at 50 to 70 MPH and firing. It's a sexy and majestic beast no doubt, however this is flying against some of the biggest cutoffs in the game i'm fine with modern-semi-modern vehicles but this is way too much; WT is still not in a position where the T-64 & 72 could be added; let alone the freaking Abrams. 

 

Also please don't use the Type 87 SPAA as justification; it is an EXCEPTION not the rule. The composite it uses was to offer similar protection with less weight than equivalent amount of RHA; not to make it practically immune to anything but weapons specifically designed to defeat it.......

 

The Abrams's UFP is just 50mm RHA. The LFP (strongest part of the hull) is only 700mm LoS at best and thus will never reach such a level of KE resistance ever, but more like 500mm or more perhaps. The XM1 also has the 105mm M68, but firing M735 APFSDS. Around 60 mph is a rumor I hear about the Abrams, but it would mostly be around 80 km/h, or 50 mph.

 

Also, the Type 87's composite is pretty damn bad from what I could see. The sloping on the plates on the inside are too bad, and before you mention the Abrams, the plates inside the composite module are not parallel to the composite block itself. They're angled already.

[Results45 2,200]

Well the highest pen ammo I can see being in game to combat T-72Bs and Kpz-70s is 120/125mm APFSDS-T penning 650mm at 1000m and even that is probably at least semi-classified (visual/demonstrated/estimated penetration values, shell kinetics, dimensions, components, etc.) 

Edited March 24, 2017 by Results45

[IOC_000 924]

1 hour ago, Nope said:

 

The Abrams's UFP is just 50mm RHA. The LFP (strongest part of the hull) is only 700mm LoS at best and thus will never reach such a level of KE resistance ever, but more like 500mm or more perhaps. The XM1 also has the 105mm M68, but firing M735 APFSDS. Around 60 mph is a rumor I hear about the Abrams, but it would mostly be around 80 km/h, or 50 mph.

 

Also, the Type 87's composite is pretty damn bad from what I could see. The sloping on the plates on the inside are too bad, and before you mention the Abrams, the plates inside the composite module are not parallel to the composite block itself. They're angled already.

 

Is also a highly classified armor package; and with a DU liner it will reach an effective LOS thickness of around 500-1100MM.  60-70 MPH is highly dependent on terrain; only on flat roads or plains will it ever reach that speed 30-40 is more realistic for a combat speed. 105MM firing a DU penetrator with better performance than every other vehicle; also FINALLY someone who understands the 87's armor

[Results45 2,200]

AFAIK, the highest penning 105mm L7 APFSDS ammo goes through around 550mm, which is probably why they upgraded to a 120mm gun to fire shells capable of punching through 750-900mm RHAe. 

Edited March 24, 2017 by Results45

[IOC_000 924]

1 minute ago, Results45 said:

AFAIK, the highest penning 105mm L7 APFSDS ammo goes through around 500mm.

And that's what? 100M? 

[Results45 2,200]

1 hour ago, IOC_000 said:

And that's what? 100M? 

 

Any of these in general (especially the higher-penning ones): http://echo501.tripod.com/Military/105ammo.htm

 

And here's estimated values for 120mm ammo: http://echo501.tripod.com/Military/120ammo.htm

Edited March 24, 2017 by Results45