|
category
|
Upper front plate of Heavy Tank M6 is 92MM at 29 degrees. Source is TM9-721-1 (Heavy Tank M6 technical manual)
Tags: Visual edit Mobile edit Mobile web edit
|
||
| (40 intermediate revisions by 30 users not shown) | |||
| Line 1: | Line 1: | ||
{{Short description|American heavy tank}} |
|||
{{More footnotes|date=January 2015}} |
{{More footnotes needed|date=January 2015}} |
||
{{Infobox weapon |
{{Infobox weapon |
||
|
| name = Heavy Tank M6 |
||
|
| image = File:M6 heavy tank TM9-2800 p120.jpg |
||
|
| image_size = 300 |
||
|
| caption = M6 prototype |
||
|
| origin = [[United States]] |
||
|
| type = [[Heavy tank]] |
||
|
| is_vehicle = yes |
||
|
| service = Trials only |
||
|
| used_by = [[United States Army]] |
||
|
| wars = World War II |
||
|
| designer = US Army Ordnance Corps |
||
|
| design_date = |
||
|
| manufacturer = [[Baldwin Locomotive]] |
||
| unit_cost = $171,615 (M6A1)<ref>{{cite book |title=Armored Champion: The Top Tanks of World War II |
|||
|unit_cost= |
|||
|first= Steven |last=Zaloga |date= 15 May 2015 |url=https://books.google.com/books?id=Y-O3DAAAQBAJ&pg=PA39 |page=39 |isbn= 9780811761338 |via=Google Books}}</ref> |
|||
|
| production_date = |
||
|
| number = 40 |
||
|
| variants = 6 |
||
|spec_label=M6 |
| spec_label = M6 |
||
|weight=126,500 lb (57.4 tonnes) combat loaded |
|||
| weight = 126,500 lb (57.4 tonnes) combat loaded<ref name="Armchair">{{cite web |last1=Johnsen|first1=Griffin |title=Evolution of American Tanks: Animated History |url=https://www.youtube.com/watch?v=MEhMOTpbWOY |website=YouTube |work= |date=23 October 2021}}</ref> |
|||
|
| length = 27 ft 8 in (8.43 m) gun forward <!-- <br /> 24 ft 9 in (7.54 m) gun aft --> |
||
|width= 10 ft 3 in (3.12 m) over track armor |
|||
|
| width = 10 ft 3 in (3.12m) over track armor |
||
| height = 9 ft 10 in (3.0 m) to turret roof <!--<br /> 10 ft 7 in (3.23 m) to top of .30 machine gun mount --> |
|||
|
| crew = 6 (commander, gunner, driver, assistant driver, loader, assistant loader)<ref name="Armchair"/> |
||
|armour=25–83 mm |
|||
| armour = 25–92 mm |
|||
<!-- Front 3.25 in (83 mm) at 30° <br /> Upper sides 1.75 in (44 mm) at 20° <br /> Lower sides 2.75 in (70 mm) at 0°<br /> Turret front 3.25 in (83 mm) at 7°<br /> Turret sides and rear 3.25 in (83 mm) at 0° --> |
|||
|
<!-- Front 3.25 in (92 mm) at 29° <br /> Upper sides 1.75 in (44 mm) at 20° <br /> Lower sides 2.75 in (70 mm) at 0°<br /> Turret front 3.25 in (83 mm) at 7°<br /> Turret sides and rear 3.25 in (83 mm) at 0° -->| primary_armament = 1 × [[3-inch M1918 gun|3 in (76.2 mm) gun M7]](75 rounds)<ref name="Armchair"/> <br /> 1 × [[37 mm Gun M3|37 mm (1.46 in) gun M6]] (202 rounds) |
||
|
| secondary_armament = 2 × [[.50 BMG|.50 cal]] (12.7mm) [[M2 Browning machine gun|Browning M2HB]] [[machine gun]]s, hull (6,900 rounds) <br /> 2 × .30 [[M1919 Browning machine gun|Browning M1919A4]] machine guns, one fixed (bow), one flexible [[anti-aircraft warfare|AA]] (5,500 rounds) |
||
|
| engine = 1,823 in<sup>3</sup> (29.88 L) [[Wright R-1820#G-200-781C9GC1|Wright G-200]] 9-cylinder [[gasoline]]<ref name="Armchair"/> |
||
|
| engine_power = 825 hp at 2,300 rpm |
||
|
| transmission = [[Timken Company|Timken]] mechanical model 16001, three speeds (two forward, one reverse); rear drive sprocket |
||
|
| fuel_capacity = 477 US gallons (1,810 L) |
||
|
| pw_ratio = 15.7 hp/tonne |
||
|
| suspension = Horizontal [[volute spring]] |
||
|
| clearance = 20.5 in (52 cm) |
||
|
| vehicle_range = 100 miles (160 km) |
||
|
| speed = 22 mph (35 km/h) |
||
}} |
}} |
||
The '''Heavy Tank M6''' was an |
The '''Heavy Tank M6''' was an American [[heavy tank]] designed during [[World War II]]. The tank was produced in small numbers and never saw combat. |
||
==Development |
==Development== |
||
[[File:Heavy-tank-OWI-4.jpg|thumb|left|T1 heavy tank prototype]] |
|||
Because of limited [[budget]]s for tank development in the interwar years, at the outbreak of World War II the [[United States |
Because of limited [[budget]]s for tank development in the interwar years, at the outbreak of World War II the [[United States Army]] possessed few tanks, though it had been keeping track of the use of tanks in Europe and Asia. Successful employment of armored units in 1939–40, mostly by the [[Nazi Germany|Germans]], gave momentum to a number of US tank programs, including a heavy tank. The United States possessed a massive industrial infrastructure and large numbers of engineers that would allow for mass production of tanks. |
||
Following the [[United States Army Infantry School#Chief of Infantry|Chief of Infantry]] recommendation from May 1940, the [[ |
Following the [[United States Army Infantry School#Chief of Infantry|Chief of Infantry]] recommendation from May 1940, the [[United States Army Ordnance Corps|US Army Ordnance Corps]] started to work on a 50-ton heavy tank design. The project was approved in June and the vehicle received the designation '''Heavy Tank T1'''. |
||
Initially, a multi-[[Gun turret|turreted]] design was proposed, with two main turrets each armed with a low-velocity T6 75 mm (2.95 inch) gun, a secondary turret with a 37 mm gun and a coaxial .30 caliber (7.62 mm) [[machine gun]], and another secondary turret with a 20 mm gun and a coaxial .30 caliber machine gun. Four .30 caliber machine guns were to be installed in ball mounts, two in the [[glacis]] (front) plate and two in the rear corners of the hull. The design was somewhat similar in concept to multi-turreted breakthrough tanks developed in Europe in the 1920s and throughout the 1930s, such as the 1925 British [[Vickers A1E1 Independent]] or the Soviet [[T-35]] of the early 1930s, albeit on a much more powerful scale: the older tank designs were typically armed with a single light or medium-caliber main gun and multiple machine guns, and had armor only sufficient to protect from small arms fire. Later in the decade, however, European tank developers switched to single-turret designs. |
Initially, a multi-[[Gun turret|turreted]] design was proposed, with two main turrets each armed with a low-velocity T6 75 mm (2.95 inch) gun, a secondary turret with a 37 mm gun and a coaxial .30 caliber (7.62 mm) [[machine gun]], and another secondary turret with a 20 mm gun and a coaxial .30 caliber machine gun. Four .30 caliber machine guns were to be installed in ball mounts, two in the [[glacis]] (front) plate and two in the rear corners of the hull. The design was somewhat similar in concept to multi-turreted breakthrough tanks developed in Europe in the 1920s and throughout the 1930s, such as the 1925 British [[Vickers A1E1 Independent]] or the Soviet [[T-35]] of the early 1930s, albeit on a much more powerful scale: the older tank designs were typically armed with a single light or medium-caliber main gun and multiple machine guns, and had armor only sufficient to protect from small arms fire. Later in the decade, however, European tank developers switched to single-turret designs. |
||
[[ |
[[File:Heavy-tank-OWI-3.jpg|thumb|left|Front view of M6, with several early [[M3 Stuart|M3 light tanks]] in the background]] |
||
[[ |
[[File:Heavy-tank-OWI-2.jpg|thumb|left|Side view]] |
||
By October, the US developers reached the same conclusion as their European counterparts. The armament was changed to a single vertically stabilized 3-inch (76.2 mm) gun and a coaxial 37 mm gun in a single three-man turret with both manual and electric traverse. The turret had a commander's cupola identical to that of the [[M3 Lee|M3 Medium Tank]].{{clarify|was this developed for both at same time? M3 still in design stage at this point |date=March 2015}} Additional armament consisted of two .50 caliber machine guns in a bow mount (operated by the assistant driver), two .30 caliber machine guns in the front plate (fired electrically by the driver), one .30 caliber in the commander's cupola and one .50 caliber in a rotor mount for anti-aircraft use in the right rear of the turret roof (operated by the loader). The crew consisted of commander (seated in the turret left), gunner to the right of the gun, gun loader (turret), driver and assistant driver in the front left and right of the hull respectively, and another crewman in the hull to pass ammunition to the turret. |
By October, the US developers reached the same conclusion as their European counterparts. The armament was changed to a single vertically stabilized 3-inch (76.2 mm) gun and a coaxial 37 mm gun in a single three-man turret with both manual and electric traverse. The turret had a commander's cupola identical to that of the [[M3 Lee|M3 Medium Tank]].{{clarify|was this developed for both at same time? M3 still in design stage at this point |date=March 2015}} Additional armament consisted of two .50 caliber machine guns in a bow mount (operated by the assistant driver), two .30 caliber machine guns in the front plate (fired electrically by the driver), one .30 caliber in the commander's cupola and one .50 caliber in a rotor mount for anti-aircraft use in the right rear of the turret roof (operated by the loader). The crew consisted of commander (seated in the turret left), gunner to the right of the gun, gun loader (turret), driver and assistant driver in the front left and right of the hull respectively, and another crewman in the hull to pass ammunition to the turret. |
||
| Line 55: | Line 57: | ||
One of the main challenges was developing a [[powerpack (drivetrain)|powerpack]] for such a heavy vehicle. The [[Wright R-1820|Wright G-200]] air-cooled [[radial engine|radial]] [[gasoline engine]] was selected by a committee formed by the [[Society of Automotive Engineers]], but no suitable [[Transmission (mechanics)|transmission]] was available. The committee recommended developing a [[Hydramatic|hydramatic transmission]], while a possibility of using a [[torque converter]] or an electric transmission was also to be checked. |
One of the main challenges was developing a [[powerpack (drivetrain)|powerpack]] for such a heavy vehicle. The [[Wright R-1820|Wright G-200]] air-cooled [[radial engine|radial]] [[gasoline engine]] was selected by a committee formed by the [[Society of Automotive Engineers]], but no suitable [[Transmission (mechanics)|transmission]] was available. The committee recommended developing a [[Hydramatic|hydramatic transmission]], while a possibility of using a [[torque converter]] or an electric transmission was also to be checked. |
||
The project was first publicly disclosed in August 1940 when the Army awarded [[Baldwin Locomotive Works]] in Pennsylvania a $5.7 million contract for the production of 50 tanks. The Army envisioned building 500 of this type.<ref>{{cite news |title=$5,689,725 Contract to Baldwin Locomotive Works Calls for 60 to 70-Ton Machines Capable of 50-Mile-an-Hour Speed |url=https://www.nytimes.com/1940/08/10/archives/article-1-no-title-5689725-contract-to-baldwin-locomotive-works.html |access-date=2 October 2018 |work=The New York Times |
The project was first publicly disclosed in August 1940 when the Army awarded [[Baldwin Locomotive Works]] in Pennsylvania a $5.7 million contract for the production of 50 tanks. The Army envisioned building 500 of this type.<ref>{{cite news |title=$5,689,725 Contract to Baldwin Locomotive Works Calls for 60 to 70-Ton Machines Capable of 50-Mile-an-Hour Speed |url=https://www.nytimes.com/1940/08/10/archives/article-1-no-title-5689725-contract-to-baldwin-locomotive-works.html |access-date=2 October 2018 |work=The New York Times |date=9 August 1940}}</ref> |
||
The first T1E1 was delivered to the Army in December 1941.<ref name="T1A1 demo">{{cite news |title=First Heavy Tank Passes Army Test |url=https://www.nytimes.com/1941/12/09/archives/first-heavy-tank-passes-army-test-fiftyseventon-fighter-shows-speed.html |access-date=2 October 2018 |work=The New York Times |date=8 December 1941}}</ref> From 1941 to 1942, three prototypes were built |
The first T1E1 was delivered to the Army in December 1941.<ref name="T1A1 demo">{{cite news |title=First Heavy Tank Passes Army Test |url=https://www.nytimes.com/1941/12/09/archives/first-heavy-tank-passes-army-test-fiftyseventon-fighter-shows-speed.html |access-date=2 October 2018 |work=The New York Times |date=8 December 1941}}</ref> From 1941 to 1942, three prototypes were built: one with electric transmission and two with torque converter transmission. Variants with hydramatic transmission were never completed. The prototypes also differed in hull assembly method: one had a welded hull and two had cast hulls. |
||
On 26 May 1942, two variants with torque converter transmission were standardized as '''M6''' and '''M6A1'''. Standardization of the electric transmission equipped T1E1 as the '''M6A2''' was never approved, but the manufacturing of the vehicle was nevertheless recommended. It was proposed by the Ordnance Corps that 115 T1E1s would be built for the US Army for "extended service tests", between that and Services of Supply instruction to increase production with the balance going to aid US allies, this would mean 50 M6s and 65 M6A1s built for the British. |
On 26 May 1942, two variants with torque converter transmission were standardized as '''M6''' (cast hull) and '''M6A1''' (welded hull). Standardization of the electric transmission equipped T1E1 as the '''M6A2''' was never approved, but the manufacturing of the vehicle was nevertheless recommended. It was proposed by the Ordnance Corps that 115 T1E1s would be built for the US Army for "extended service tests", between that and Services of Supply instruction to increase production with the balance going to aid US allies, this would mean 50 M6s and 65 M6A1s built for the British.{{sfn|Hunnicutt|1988|p=47-48}} Production started in December 1942. |
||
Some minor changes were introduced in the production vehicles: the cupola was replaced by a double-door hatch with a ring mount, the machine gun in a rotor mount and the left front machine gun were removed. |
Some minor changes were introduced in the production vehicles: the cupola was replaced by a double-door hatch with a ring mount, while the machine gun in a rotor mount and the left front machine gun were removed. |
||
However, by the time the M6 was ready for production, the Armored Corps had lost interest in the project. The advantages the M6 offered over medium tanks – its much thicker armor and slightly more powerful gun – were offset partly by the shortcomings of the design – such as very high silhouette, awkward internal layout and reliability problems – and partly by logistical concerns due to its weight. |
However, by the time the M6 was ready for production, the Armored Corps had lost interest in the project. The advantages the M6 offered over medium tanks – its much thicker armor and slightly more powerful gun – were offset partly by the shortcomings of the design – such as very high silhouette, awkward internal layout and reliability problems – and partly by logistical concerns due to its weight. |
||
In early 1942, the Ordnance Department set a production target of 250 a month, with Fisher as a second contractor to meet a planned expansion in the size of the army.<ref name=CandEp115>Chamberlain & Ellis, |
In early 1942, the Ordnance Department set a production target of 250 a month, with Fisher as a second contractor to meet a planned expansion in the size of the army.<ref name=CandEp115>Chamberlain & Ellis, page 155</ref> However, by September, the focus had changed, with tank production scaled back and more aircraft for the USAAF. Under this new "Army Supply Program", the M6 production was cut from 5,000 to a little over 100.<ref name=CandEp115 /> |
||
By the end of 1942, the Armored Corps were of the opinion that the new [[M4 Sherman]] gave adequate solution for the present and the near future, while being reliable, cheap and much easier to transport and they had no need for a heavy tank. In 1943, the production target was reduced again, down to 40,<ref name=CandEp115/> being an economic cut-off. |
By the end of 1942, the Armored Corps were of the opinion that the new [[M4 Sherman]] gave adequate solution for the present and the near future, while being reliable, cheap and much easier to transport and they had no need for a heavy tank. In 1943, the production target was reduced again, down to 40,<ref name=CandEp115/> being an economic cut-off.{{sfn|Hunnicutt|1988|p=49}} |
||
Production M6 and pilot M6A1 examples were evaluated at Fort Knox in the early part of 1943. The reports were critical of the awkward and inefficient crew stations, and the superfluous 37mm gun. |
Production M6 and pilot M6A1 examples were evaluated at Fort Knox in the early part of 1943. The reports were critical of the awkward and inefficient crew stations, and the superfluous 37mm gun.{{sfn|Hunnicutt|1988|p=50-54}} However, in October, the tank had performed well enough at [[Aberdeen Proving Ground]] to proceed.<ref name="Aberdeen">{{cite news |last1=Baldwin |first1=Hanson W. |title=Monster Tanks and Light Rifles Among Arms Tested at Aberdeen |url=https://www.nytimes.com/1943/10/16/archives/monster-tanks-and-light-rifles-among-arms-tested-at-aberdeen.html |access-date=2 October 2018 |work=The New York Times |date=7 October 1943}}</ref> |
||
The Ordnance Corps had expected the |
The Ordnance Corps had expected the 76 mm gun to be lacking, and the T1E1 prototype was tested with a T7 90 mm gun and was found to be a satisfactory gun platform, although the poor turret layout was again noted. By this point, the M6 had been cancelled.{{sfn|Hunnicutt|1988|p=54}} |
||
In August 1944, the Ordnance Corps recommended modifying the T1E1s to build 15 specially armored and armed tanks to meet a need for attacking heavily fortified areas. These 77-ton vehicles – designated '''M6A2E1''' – with thicker (equivalent to {{convert|7.5|in|mm|adj=on}} vertical protection) glacis armor and a turret developed for the [[T29 Heavy Tank]], armed with a T5E1 105 mm gun but no increase in engine power. Ordnance believed they could be delivered by November. The proposal was put to the supreme commander in Europe [[Dwight D. Eisenhower|General Eisenhower]], who rejected them as impracticable. Two tanks were used to test the T29 turret and gun, but their armor was not modified. |
In August 1944, the Ordnance Corps recommended modifying the T1E1s to build 15 specially armored and armed tanks to meet a need for attacking heavily fortified areas. These 77-ton vehicles – designated '''M6A2E1''' – with thicker (equivalent to {{convert|7.5|in|mm|adj=on}} vertical protection) glacis armor and a turret developed for the [[T29 Heavy Tank]], armed with a T5E1 105 mm gun but no increase in engine power. Ordnance believed they could be delivered by November. The proposal was put to the supreme commander in Europe [[Dwight D. Eisenhower|General Eisenhower]], who rejected them as impracticable. Two tanks were used to test the T29 turret and gun, but their armor was not modified.{{sfn|Hunnicutt|1988|p=57-59}} |
||
On 14 December 1944, the M6 was declared obsolete. Only 40 had been produced and they never left US soil. Several toured the United States for propaganda purposes, where they gave performance displays (such as car crushing) at [[War Bond]] drives and the like. All were eventually scrapped except for a single T1E1, which was put on display at the [[United States Army Ordnance Museum]], [[Aberdeen, Maryland]]. |
On 14 December 1944, the M6 was declared obsolete. Only 40 had been produced and they never left US soil. Several toured the United States for propaganda purposes, where they gave performance displays (such as car crushing) at [[War Bond]] drives and the like. All were eventually scrapped except for a single T1E1, which was put on display at the [[United States Army Ordnance Museum]], [[Aberdeen, Maryland]]. |
||
The British used the suspension of the M6 in the first of their two [[Excelsior tank|A33 Heavy Assault Tank "Excelsior"]] prototypes. |
The British used the [[horizontal volute spring suspension]] system of the M6 in the first of their two [[Excelsior tank|A33 Heavy Assault Tank "Excelsior"]] prototypes. |
||
==Variants== |
==Variants== |
||
[[ |
[[File:M6A1 heavy tank TM9-2800 p122.jpg|thumb|M6A1; note the angular welded hull]] |
||
[[ |
[[File:T1E1 heavy tank TM9-2800 p124.jpg|thumb|T1E1]] |
||
[[ |
[[File:M6a2e1.jpg|thumb|M6A2E1 at Aberdeen Proving Ground, June 1945]] |
||
* |
*'''T1''' – Cast hull, hydramatic transmission. Never built. |
||
* |
*'''T1E1''' – Cast hull, [[General Electric]] electrical transmission.{{sfn|Hunnicutt|1988|p=37}} Standardization proposed as '''M6A2''' but not accepted. 20 units built. |
||
* |
*'''T1E2''' / '''M6''' – Cast hull, torque converter transmission. 8 units built. |
||
* |
*'''T1E3''' / '''M6A1''' – Welded hull, cast turret, [[torque converter]] transmission. 12 units built. |
||
* |
*'''T1E4''' – Welded hull, hydramatic transmission. Four GM engines.<ref name=H37>Hunnicutt p37</ref> Cancelled 1942. Never built. |
||
* |
*'''M6A2E1''' – Uparmored T1E1 fitted with a new turret with a T5E1 105 mm gun. Used for testing [[T29 Heavy Tank|T29 heavy tank project]] armament system. Project cancelled at 22 August 1944.<ref>{{Cite web|url=http://tankarchives.blogspot.com/2016/03/m6a2e1-heavy-clownshoe.html|title=M6A2E1: Heavy Clownshoe|access-date=2017-06-26}}</ref> 2 units built. |
||
==See also== |
==See also== |
||
{{Portal|Tanks}} |
|||
* |
*[[List of U.S. military vehicles by supply catalog designation]] |
||
* |
*[[List of U.S. military vehicles by model number]] |
||
* |
*[[TOG2 (tank)|TOG II*]] – British superheavy prototype tank for trench warfare |
||
* |
*[[T29 Heavy Tank|T29]] – late-war prototype heavy tank; early version turret and gun was tested on M6A2E1 variant |
||
;Tanks of comparable role, performance and era |
;Tanks of comparable role, performance and era |
||
* British [[Excelsior tank|Excelsior]] – prototype heavy tank, two built, did not enter service |
*German [[VK 30.01 (H)]] – prototype for the [[Tiger I]] |
||
*British [[Excelsior tank|Excelsior]] – prototype heavy tank, two built, did not enter service |
|||
* |
*British [[Churchill tank|Churchill]] – heavy tank, entered service in 1941 |
||
* |
*American-British [[T14 Heavy Tank|T14]] – prototype heavy tank with similar specifications |
||
* |
*Soviet [[Kliment Voroshilov tank|KV-1]] – heavy tank, entered service in 1939 |
||
*Hungarian [[44M Tas]] – prototype heavy tank, didn't enter production due to military/political situation |
|||
;Contemporaries to M6A2E1 variant |
;Contemporaries to M6A2E1 variant |
||
* |
*German [[Tiger II]] – late-war heavy tank, entered service in 1944 |
||
* |
*United States [[M26 Pershing#Super Pershing 2|T26E4 "Super Pershing"]] heavy tank – single prototype [[M26 Pershing]] with extra armor and improved gun; fought in Western Europe during 1945 |
||
* |
*Soviet [[IS tank family|IS-2 model 1944]] – heavy assault tank, entered service in 1944 |
||
* |
*Soviet [[IS tank family|IS-3]] – heavy tank, entered service in 1945, did not see combat |
||
*French [[ARL 44]] – heavy tank, too late to see service |
|||
==References== |
==References== |
||
| Line 113: | Line 118: | ||
==Sources== |
==Sources== |
||
* |
*{{citation |title=British and American Tanks of World War II |first1=Peter |last1=Chamberlain |first2=Chris |last2=Ellis |publisher=Arco Publishing |date=1969 |name-list-style=amp }} |
||
* R.P. Hunnicutt |
*{{citation |last1=Hunnicutt |first1=Richard Pearce |author1-link= R. P. Hunnicutt |title=Firepower: A History of the American Heavy Tank |year=1988 |publisher=Presidio Press |location=Novato, California |isbn=0-89141-304-9 |pages=|chapter= |url=https://archive.org/details/firepowerhistory0000hunn}} |
||
* |
*{{citation |series=AFV Weapons |title=No. 32: The M6 Heavy and M26 Pershing |first=Robert J. |last=Icks |date= 1971 |publisher=Profile Publishing}} |
||
==External links== |
==External links== |
||
{{commons|M6 Heavy tank}} |
{{commons|M6 Heavy tank}} |
||
* |
*[https://web.archive.org/web/20070102185303/http://wwiivehicles.com/usa/tanks_heavy/m6_heavy.html M6 at World War II vehicles] |
||
* |
*[http://afvdb.50megs.com/usa/heavytankm6.html Heavy Tank M6] M6 at AFV database |
||
{{WWIIAmericanAFVs}} |
{{WWIIAmericanAFVs}} |
||
| Line 132: | Line 137: | ||
[[Category:Abandoned military projects of the United States]] |
[[Category:Abandoned military projects of the United States]] |
||
[[Category:History of the tank]] |
[[Category:History of the tank]] |
||
[[Category:Military |
[[Category:Military vehicles introduced from 1940 to 1944]] |
||
 |
This article includes a list of general references, but it lacks sufficient corresponding inline citations. Please help to improve this article by introducing more precise citations. (January 2015) (Learn how and when to remove this message)
|
| Heavy Tank M6 | |
|---|---|
M6 prototype
| |
| Type | Heavy tank |
| Place of origin | United States |
| Service history | |
| In service | Trials only |
| Used by | United States Army |
| Wars | World War II |
| Production history | |
| Designer | US Army Ordnance Corps |
| Manufacturer | Baldwin Locomotive |
| Unit cost | $171,615 (M6A1)[1] |
| No. built | 40 |
| Variants | 6 |
| Specifications (M6) | |
| Mass | 126,500 lb (57.4 tonnes) combat loaded[2] |
| Length | 27 ft 8 in (8.43 m) gun forward |
| Width | 10 ft 3 in (3.12 m) over track armor |
| Height | 9 ft 10 in (3.0 m) to turret roof |
| Crew | 6 (commander, gunner, driver, assistant driver, loader, assistant loader)[2] |
| Armor | 25–92 mm |
Main | 1 × 3 in (76.2 mm) gun M7(75 rounds)[2] 1 × 37 mm (1.46 in) gun M6 (202 rounds) |
Secondary | 2 × .50 cal (12.7mm) Browning M2HB machine guns, hull (6,900 rounds) 2 × .30 Browning M1919A4 machine guns, one fixed (bow), one flexible AA (5,500 rounds) |
| Engine | 1,823 in3 (29.88 L) Wright G-200 9-cylinder gasoline[2] 825 hp at 2,300 rpm |
| Power/weight | 15.7 hp/tonne |
| Transmission | Timken mechanical model 16001, three speeds (two forward, one reverse); rear drive sprocket |
| Suspension | Horizontal volute spring |
| Ground clearance | 20.5 in (52 cm) |
| Fuel capacity | 477 US gallons (1,810 L) |
Operational | 100 miles (160 km) |
| Maximum speed | 22 mph (35 km/h) |
The Heavy Tank M6 was an American heavy tank designed during World War II. The tank was produced in small numbers and never saw combat.
Because of limited budgets for tank development in the interwar years, at the outbreak of World War II the United States Army possessed few tanks, though it had been keeping track of the use of tanks in Europe and Asia. Successful employment of armored units in 1939–40, mostly by the Germans, gave momentum to a number of US tank programs, including a heavy tank. The United States possessed a massive industrial infrastructure and large numbers of engineers that would allow for mass production of tanks.
Following the Chief of Infantry recommendation from May 1940, the US Army Ordnance Corps started to work on a 50-ton heavy tank design. The project was approved in June and the vehicle received the designation Heavy Tank T1.
Initially, a multi-turreted design was proposed, with two main turrets each armed with a low-velocity T6 75 mm (2.95 inch) gun, a secondary turret with a 37 mm gun and a coaxial .30 caliber (7.62 mm) machine gun, and another secondary turret with a 20 mm gun and a coaxial .30 caliber machine gun. Four .30 caliber machine guns were to be installed in ball mounts, two in the glacis (front) plate and two in the rear corners of the hull. The design was somewhat similar in concept to multi-turreted breakthrough tanks developed in Europe in the 1920s and throughout the 1930s, such as the 1925 British Vickers A1E1 Independent or the Soviet T-35 of the early 1930s, albeit on a much more powerful scale: the older tank designs were typically armed with a single light or medium-caliber main gun and multiple machine guns, and had armor only sufficient to protect from small arms fire. Later in the decade, however, European tank developers switched to single-turret designs.
By October, the US developers reached the same conclusion as their European counterparts. The armament was changed to a single vertically stabilized 3-inch (76.2 mm) gun and a coaxial 37 mm gun in a single three-man turret with both manual and electric traverse. The turret had a commander's cupola identical to that of the M3 Medium Tank.[clarification needed] Additional armament consisted of two .50 caliber machine guns in a bow mount (operated by the assistant driver), two .30 caliber machine guns in the front plate (fired electrically by the driver), one .30 caliber in the commander's cupola and one .50 caliber in a rotor mount for anti-aircraft use in the right rear of the turret roof (operated by the loader). The crew consisted of commander (seated in the turret left), gunner to the right of the gun, gun loader (turret), driver and assistant driver in the front left and right of the hull respectively, and another crewman in the hull to pass ammunition to the turret.
One of the main challenges was developing a powerpack for such a heavy vehicle. The Wright G-200 air-cooled radial gasoline engine was selected by a committee formed by the Society of Automotive Engineers, but no suitable transmission was available. The committee recommended developing a hydramatic transmission, while a possibility of using a torque converter or an electric transmission was also to be checked.
The project was first publicly disclosed in August 1940 when the Army awarded Baldwin Locomotive Works in Pennsylvania a $5.7 million contract for the production of 50 tanks. The Army envisioned building 500 of this type.[3]
The first T1E1 was delivered to the Army in December 1941.[4] From 1941 to 1942, three prototypes were built: one with electric transmission and two with torque converter transmission. Variants with hydramatic transmission were never completed. The prototypes also differed in hull assembly method: one had a welded hull and two had cast hulls.
On 26 May 1942, two variants with torque converter transmission were standardized as M6 (cast hull) and M6A1 (welded hull). Standardization of the electric transmission equipped T1E1 as the M6A2 was never approved, but the manufacturing of the vehicle was nevertheless recommended. It was proposed by the Ordnance Corps that 115 T1E1s would be built for the US Army for "extended service tests", between that and Services of Supply instruction to increase production with the balance going to aid US allies, this would mean 50 M6s and 65 M6A1s built for the British.[5] Production started in December 1942.
Some minor changes were introduced in the production vehicles: the cupola was replaced by a double-door hatch with a ring mount, while the machine gun in a rotor mount and the left front machine gun were removed.
However, by the time the M6 was ready for production, the Armored Corps had lost interest in the project. The advantages the M6 offered over medium tanks – its much thicker armor and slightly more powerful gun – were offset partly by the shortcomings of the design – such as very high silhouette, awkward internal layout and reliability problems – and partly by logistical concerns due to its weight.
In early 1942, the Ordnance Department set a production target of 250 a month, with Fisher as a second contractor to meet a planned expansion in the size of the army.[6] However, by September, the focus had changed, with tank production scaled back and more aircraft for the USAAF. Under this new "Army Supply Program", the M6 production was cut from 5,000 to a little over 100.[6]
By the end of 1942, the Armored Corps were of the opinion that the new M4 Sherman gave adequate solution for the present and the near future, while being reliable, cheap and much easier to transport and they had no need for a heavy tank. In 1943, the production target was reduced again, down to 40,[6] being an economic cut-off.[7]
Production M6 and pilot M6A1 examples were evaluated at Fort Knox in the early part of 1943. The reports were critical of the awkward and inefficient crew stations, and the superfluous 37mm gun.[8] However, in October, the tank had performed well enough at Aberdeen Proving Ground to proceed.[9]
The Ordnance Corps had expected the 76 mm gun to be lacking, and the T1E1 prototype was tested with a T7 90 mm gun and was found to be a satisfactory gun platform, although the poor turret layout was again noted. By this point, the M6 had been cancelled.[10]
In August 1944, the Ordnance Corps recommended modifying the T1E1s to build 15 specially armored and armed tanks to meet a need for attacking heavily fortified areas. These 77-ton vehicles – designated M6A2E1 – with thicker (equivalent to 7.5-inch (190 mm) vertical protection) glacis armor and a turret developed for the T29 Heavy Tank, armed with a T5E1 105 mm gun but no increase in engine power. Ordnance believed they could be delivered by November. The proposal was put to the supreme commander in Europe General Eisenhower, who rejected them as impracticable. Two tanks were used to test the T29 turret and gun, but their armor was not modified.[11]
On 14 December 1944, the M6 was declared obsolete. Only 40 had been produced and they never left US soil. Several toured the United States for propaganda purposes, where they gave performance displays (such as car crushing) at War Bond drives and the like. All were eventually scrapped except for a single T1E1, which was put on display at the United States Army Ordnance Museum, Aberdeen, Maryland.
The British used the horizontal volute spring suspension system of the M6 in the first of their two A33 Heavy Assault Tank "Excelsior" prototypes.
|
| |||||||
|---|---|---|---|---|---|---|---|
| Tanks |
| ||||||
| Self-propelled artillery |
| ||||||
| Tank destroyers |
| ||||||
| Armored carriers |
| ||||||
| Amphibious vehicles |
| ||||||
| Armored cars |
| ||||||
| Self-propelled anti-aircraft guns |
| ||||||
| Experimental and short production run vehicles |
| ||||||
| Lend-Lease |
| ||||||
American armored fighting vehicle production during World War II | |||||||
