The ultimate American tank hunter of WW2
The M36 Jackson was the last dedicated American tank hunter of the war. After the early, soon obsolete M10 Wolverine and the superfast M18 Hellcat, the US Army needed a more powerful gun and better armored vehicle to hunt down the latest developments in German tanks, including the Panther and Tigers. Indeed, in September 1942, it was already foreseen that the standard 75 mm (3 in) M7 gun of the M10 was only efficient at short range (500 m) against the enemy vehicles. Engineers were tasked with devising a new 90 mm (3.54 in) gun, which became the M3 gun, to engage German tanks on equal terms considering range. This gun was also used by the M26 Pershing.
M10A1 GMC in trials, 1943. The T71 was developed on this hull and chassis.
The need for a better armed tank hunter was confirmed, at a high cost, in the battle of Kasserine pass and later in multiple engagements in Sicily and Italy. The new tank equipped with this gun was designed quickly on the basis of the M10 tank destroyer. At first, the T53 sought a dual AA/AT rôle, but was eventually canceled.
The T71, which would become the M36, was completed in March 1943. However, due to multiple issues, the production only started mid-1944 and the first deliveries came in September 1944, two years after the idea was first proposed. This new tank hunter was known by the soldiers as “Jackson” in reference to the Confederate general of the Civil War Stonewall Jackson, or “Slugger”. Officially, it was named “M36 tank destroyer” or “90 mm Gun Motor Carriage M36” by the ordnance and US Army at large. It proved itself vastly superior to the M10, and was arguably the finest American tank hunter of World War Two, with a long postwar career.
T71 GMC pilot prototype in 1943
The first M36 prototype was completed in March 1943. It was characterized by a new turret mounting the 90 mm M3 gun on a standard M10 chassis. The prototype designated T71 Gun Motor Carriage and passed all tests with success, proving lighter and thus more agile than the regular Sherman M4A3. An order for 500 was issued. Upon standardization, the designation was changed to “90 mm Gun Motor Carriage M36” in June 1944. These were produced by the Fisher Tank Division (General Motors), Massey Harris Co., American Locomotive Co. and Montreal Locomotive Works (chassis) and hulls by the Grand Blanc Arsenal. The M36 was based on the upgraded M10A1 Wolverine hull, whereas the B2 was based on the regular M10 chassis/M4A3 diesel.
M36B2 at Danbury, – side view
Like all US tank destroyers, the turret was open-topped to save weight and provide better peripheral observation. However, the turret design was not a simple repeat of the sloped plates of the M10 but rather a thick casting with front and side slopes and a backwards recline. A bustle acting as turret basket was welded on this casting to the rear, providing extra ammo storage (11 rounds) as well as acting as a counterweight for the M3 main gun (47 rounds, HE and AP). The main secondary armament, the usual dual purpose “Ma Deuce” cal.50 (12.7 mm) Browning M2 heavy machine gun was installed on a pintle mount on this bustle, but there was no coaxial MG. The B1 variant introduced a secondary Browning M1919 cal.30 in the hull. Postwar modifications included a folding armored roof kit to provide some protection against shrapnel, but also later fitting of a hull ball mount Browning cal.30 machine gun on the co-driver’s position and the new M3A1 gun.
GMC 6046 engine
The chassis was basically the same as the M10, with a Ford GAA V-8 gasoline 450 hp (336 kW) which gave a 15.5 hp/ton ratio, coupled with a Synchromesh gearbox with 5 forward and 1 reverse ratio. With 192 gallons of gasoline, this gave a 240 km (150 mi) range on roads with a top speed on flat ground of up to 48 km/h (30 mph). The running gear was comprised of three bogies with Vertical Volute Spring Suspension (VVSS), 12 rubberized roadwheels, with front idlers and rear drive sprockets. Hull protection counted on 13 mm thick add-on bolted armored panels like the M10 and ranged from 9 mm (035 in) to 108 mm (4.25 in) on the gun mantlet and front hull glacis plate. In detail these figures were:
Glacis front hull 38–108 mm / 0–56 °
Side (hull) 19–25 mm / 0–38 °
Rear (hull) 19–25 mm / 0–38 °
Top (hull) 10–19 mm / 90 °
Bottom (hull) 13 mm / 90 °
Front (turret) 76 mm /0 °
Sides (turret) 31,8 mm / 5 °
Rear (turret) 44,5–130 mm / 0 °
Top (turret) 0–25 mm /90 °
M36 (standard): 3″ GMC M10A1 hull (M4A3 chassis, 1,298 produced/converted)
M36B1: Conversion on M4A3 hull and chassis. (187).
M36B2: Conversion on M4A2 chassis (same hull as M10) with a twin 6-71 arrangement GM 6046 diesel (287).
M36B2 GMC at Danbury
The M36 in action
Although fielded much earlier for training, the first M36 in organic tank hunter units, in accordance with the US TD doctrine, arrived in September 1944 on the European Theater of Operations (also at the insistence of Eisenhower that regularly had reports about the Panther). It showed itself a formidable opponent for German tanks, largely on par with the British Firefly (also based on the Sherman). In addition, between October and December 1944, 187 conversions of standard Medium Tank M4A3 hulls into M36s were performed at the Grand Blanc Arsenal. These were designated M36B1 and rushed to the European Theater of Operations to combat alongside regular M36s. Later in the war, M4A2 (diesel versions) were also converted as B2s. The latter, in addition to their roof-mounted add-on armor folding panels, also had an upgraded M3 main gun with a muzzle brake.
The M36 was capable of nailing down any known German tanks at reasonable range (1,000 to 2,500 m depending of the armor thickness to deal with). Its gun left little smoke when firing. It was liked by its crew, but because of its high demand, fell rapidly in short supply: Only 1,300 M36s were manufactured in all, of which perhaps 400 were available in December 1944. However, like other US tanks hunters, it was still vulnerable to shell fragments and snipers due to its open-top turret. Field modifications, like for the M10, were hastily performed by the crews, welding additional roof iron plating. Later on, a kit was developed to protect against shrapnel, made of folding panels adopted by the M36B2, generalized after the war. When entirely closed there was a gap above the turret allowing the crew to still have a good peripheral vision. The other backsides was the choice of its Sherman chassis with a high transmission tunnel which made for a conspicuous target at 10 feet tall.
In an engagement with a German Panther tank at 1500 yards, an M36 of the 776th TD Battalion was able to penetrate the turret armor which became the commonplace preferred target, along with the sides, rather than the glacis. Tigers were harder to handle and needed to be engaged at smaller ranges. Mediums were relatively easier prey until the end of the war. The King Tiger was a slight problem, but it could still be destroyed with the proper range, angle and ammo. As an example, near Freihaldenhoven in December 1944, an M36 from the 702nd TD Battalion knocked out a King Tiger at 1,000 yards by a side shot in the turret. Panthers were generally knocked out at 1,500 yards.
M36 GMC, December 1944, en route to the battle of the BulgeDuring the Battle of the Bulge, the 7th AD was engaged, with its M36s, at St Vith with success, despite artillery shelling and wood splinters, or the presence of snipers in these woody areas. M18 Hellcats (such as those of the 705th TD Bat.) also did wonders and all combined American TDs destroyed 306 German tanks during this campaign. It should be noted there were still numerous towed battalions at that time, which suffered the highest losses. The roof vulnerability of the M36 did much to rush out the arrival of the M26 Pershing, similarly armed. In addition, specialized semi-independent TD battalions ceased to be used and the M36s (the TD doctrine had been discredited meanwhile) were now operated within mechanized groups, fighting alongside infantry.Indeed at the time of the attack of the Siegfried lines, the M36 was used in close proximity of the troops and proved quite useful with HE shells against German bunkers. A postwar study alleged that the 39 TDs battalions knocked out no less than 1,344 German tanks and assault tanksuntil the end of the war, while the best battalion claimed 105 Germans tanks and TDs. The average kill count per battalion was 34 enemy tanks/assault guns, but also 17 pillboxes, 16 MG nests, and 24 vehicles.When the M36s and M18s started to arrive in force in Europe, M10 were gradually reassigned to less sensitive sectors and sent to the Pacific. They were first used at Kwajalein, in February 1944. No less than seven TD battalions operated there with M10s and M18s, but no M36s. Some M36s did eventually serve in Asia, in French use, at first with the Free Forces, then after the war with more US supplied vehicles arriving in Indochina.
The M36’s main gun was still a match for the first modern MBTs. However, as most US WWII tanks, it was used in the Korean War and proved well capable of destroying the T-34/85s fielded by the North Koreans. They were judged as faster and more agile than the M26 but still much better armed than lighter tanks like the M24 and, some years after, the M41. The hull ball-mounted machine gun on the co-driver’s side was a postwar addition to all surviving M36s, and later an M3A1 90 mm gun (shared with the M46 Patton) was mounted instead of the 90 mm M3. This new gun can be recognized by its muzzle brake and bore evacuator. M36s were prioritized for the Military Assistance Program transfer towards South Korea over the more modern but similarly armed M26/M46. 110 M36s along with a few M10 TDs were transferred to the South Korean Army, serving until 1959. Many also found their way into other armies, although in limited numbers.
In Asia, after South Korea, the Army of the Republic of China acquired just 8 ex-French M36s in 1955, stationed on Kinmen Island until April 2001. At that time, two were still registered for training in Lieyu. The French also acquired some postwar, which were found in action in the 1st Indo-China war. Indeed, against the threat of a possible Chinese intervention and use of the IS-2 heavy tank, a Panther was first tested without success, and M36B2s were sent instead with the RBCEO and custom modifications (roof plates and additional .30 cal) in 1951. As the threat never materialized, these were used for infantry support until 1956.
Italy also received some postwar, deactivated in the 1960s. Another European operator was Yugoslavia (postwar). By the 1970s, these were modernized with a T-55 Soviet-made 500 hp diesel. After the partition of the country, existing M36s were passed to the successor states and saw heavy action, in particular in the Croatian War of Independence (1991–1995, withdrawn in 1995) but also with the Serbian forces in Bosnia, Croatia, and Kosovo War as decoys for NATO air strikes.
M36s were also purchased after the partition of India, seeing action on both sides in the Indo-Pakistani War of 1965. The Indian 25th and 11th cavalry units used these as mediums due to their mobility. However, the Indians claimed 12 Pakistani M36B2s in the battle of Asal Uttar alone, and the remainder were decommissioned before the battle of 1971.
ROCA (Republic of China Army) M36 on display at the Chengkungling museum.
Iran was also provided M36s before the revolution of 1979, and saw action in the Iran-Iraq war. The Iraqis managed to capture a few M36s and M36B1s which also were deployed in the 1991 Gulf War. Other operators included the Philippine Army (until the 1960s) and Turkey (222 donated, now long deactivated). Many surviving vehicles were maintained in running conditions and some found their ways into museums and private collections around the world.
South Korean M36B2 or modernized M36, South Korean Army (Seoul Museum, Flickr)
|Dimensions (L x W x H)||5.88 without gun x 3.04 x 2.79 m (19’3″ x 9’11” x 9’2″)|
|Total weight, battle ready||29 tonnes|
|Crew||4 (driver, commander, gunner, loader)|
|Propulsion||Ford GAA V-8, gasoline, 450 hp, 15.5 hp/t|
|Speed (road)||48 km/h (30 mph)|
|Range||240 km (150 mi) on flat|
|Armament||90 mm M3 (47 rounds)
cal.50 AA machine gun(1000 rounds)
|Armor||8 mm to 108 mm front (0.31-4.25 in)|
|Total production||1772 in 1945|
Rare restored footage: TD Boot Cam color 1943
M36 Jackson, early type in trials in UK, summer 1944. Notice the muzzle-less gun and absent add-on side armour plates
Regular M36 Jackson in Belgium, December 1944.
M36 Tank Destroyer camouflaged in a winter livery, west bank of the Rhine, January 1945.
Mid-production M36 “Pork Shop”, U.S. Army, 2nd Cavalry, Third Army, Germany, March 1945.
Late Gun Motor Carriage M36, Belgium, December 1944.
M36B1 in Germany, March-April 1945.
French M36B2 “Puma” of the Régiment Blindé Colonial d’Extrême Orient, Tonkin, 1951. Notice the extra cal.30.
Iraqi M36B1 (ex. Iranian), 1991 Gulf War
Croatian M36 077 “Topovnjaca”, War of Independence, Dubrovnik brigade, 1993.