The
76 mm Gun Motor Carriage (GMC) M18 was an
AmericanThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
tank destroyerA self-propelled anti-tank gun, or tank destroyer, is a type of armored fighting vehicle designed specifically to engage enemy armored vehicles. Many have been produced as a tank-like vehicle, but with light armor and capable of higher speed, with a gun or missile launcher. Many lack turrets...
of
World War IIWorld War II, or the Second World War , was a global military conflict which involved a majority of the world's nations, including all great powers, organized into two opposing military alliances: the Allies and the Axis...
. The manufacturer,
BuickBuick is a marque of automobile sold in the United States, Canada, Mexico, China, Taiwan, Qatar, Kuwait, and Israel by General Motors Company...
, gave it the nickname
"Hellcat" and it was the fastest tracked armored fighting vehicle during the war with a top speed up to 60 mph.
History
In December 1941, the Ordnance Corps issued a requirement for the design of a fast tank destroyer using a
Christie suspensionThe Christie suspension is a suspension system developed by American engineer Walter Christie for his tank designs. It allowed considerably longer movement than conventional leaf spring systems then in common use, which allowed his tanks to have considerably greater cross-country speed and a lower...
, the
Wright Continental R-975The Wright R-975 Whirlwind was a radial engines developed in the United States by Wright Aeronautical .-History:...
engine and a 37 mm gun.
In the light of experience gained in
North AfricaDuring the Second World War, the North African Campaign took place in North Africa from 10 June 1940 to 16 May 1943. It included campaigns fought in the Libyan and Egyptian deserts and in Morocco and Algeria and Tunisia .The campaign was fought between the Allies and Axis powers...
, the 37 mm gun was found to be inadequate and the design was changed to use a
57 mm gunThe Ordnance QF 6-pounder 7 cwt, or just 6 pounder, was a British 57 mm gun, their primary anti-tank gun during the middle of World War II, as well as the main armament for a number of armoured fighting vehicles...
. During the development process, the design was further upgunned to a
75 mm gunThe US 75 mm gun was an American tank gun of the Second World War. there were two main models, M2 and M3.Besides use on the two main American medium tanks of the war the M3 Lee and the M4 Sherman, the gun was also used to equip the Light Tank M24. a and the B-25 Mitchell bomber...
, and then finally to the
76 mm gunThe 76 mm M1 Gun was an American Forces World War II-era tank gun, which replaced the 75 mm gun on late Medium tank M4s, and was used for all 76 mm Gun Motor Carriage M18 tank destroyers....
. The Christie suspension requirement was also dropped and replaced with a torsion bar suspension. The design was standardized in February 1943 and production began in July 1943.
As a new design, the M18 incorporated several innovative maintenance features. The Wright R-975 engine was mounted on steel rollers, which permitted it to be disconnected from the
transmissionA transmission or gearbox provides speed and torque conversions from a rotating power source to another device using gear ratios, including for a motor vehicle partly because of the limitations of internal combustion engines...
, rolled out onto the lowered engine rear cover, serviced and then reconnected to the vehicle. Similarly, the transmission could be removed and rolled out onto a front deck plate to allow repairs and inspection.
The T70 prototype for the M18 first saw combat at
AnzioOperation Shingle , during the Italian Campaign of World War II, was an Allied amphibious landing against Axis forces in the area of Anzio and Nettuno, Italy. The operation was commanded by Major General John P. Lucas and was intended to outflank German forces of the Winter Line and enable an...
,
ItalyThe Italian Campaign of World War II was the name of Allied operations in and around Italy, from 1943 to the end of the war. Joint Allied Forces Headquarters AFHQ was operationally responsible for all Allied land forces in the Mediterranean theatre, and it planned and commanded the invasion of...
, and production versions of the M18 were used in
North-West EuropeThe European Theater of Operations , is the term used in the United States to refer to US operations north of Italy and the Mediterranean coast, in the European Theatre of World War II.-Definitions:...
and Italy from the summer of 1944 onwards.
In contrast to the M10 tank destroyer, which used the chassis of the
M4 ShermanThe M4 Sherman, formally Medium Tank, M4, was the primary tank used by the United States during World War II. It was also distributed to the Allies via lend lease. Evolved from previous medium and light tanks, it was the first American medium tank with a fully traversing turret for the main gun...
, the M18 Hellcat was designed from the start to be a fast tank destroyer. As a result it was smaller, lighter and significantly faster, but carried the same gun as the Sherman 76 mm models. The M18 carried a five-man crew as well as 45 rounds of main gun
ammunitionAmmunition, often informally referred to as ammo, is a generic term derived from the French language la munition which embraced all material used for war , but which in time came to refer specifically to gunpowder and artillery. The collective term for all types of ammunition is munitions...
and an M2 Browning machine gun on a flexible ring mount.
The main disadvantage of the M18 was its very light armor and the inconsistent performance of its 76 mm gun against the frontal
armorMilitary vehicles are commonly armoured to withstand the impact of shrapnel, bullets, missiles, or shells, protecting the personnel inside from enemy fire. Such vehicles include tanks, aircraft, and ships.Civilian vehicles may also be armoured...
of later German designs such as the
TigerTiger tank can refer to two German tanks of the Second World War:*Tiger I, Panzerkampfwagen VI Tiger I*Tiger II, Panzerkampfwagen VI Ausf. B Tiger II, also known as Königstiger, "King Tiger" or "Royal Tiger"...
and
PantherThe Panther was a tank fielded by Nazi Germany in World War II that served from mid-1943 to the end of the European war in 1945. It was intended as a counter to the T-34, and to replace the Panzer III and IV, though it served along with them as well as the heavier Tiger tanks until the end of the...
. The open-topped
turretA gun turret is a device that protects the crew or mechanism of a projectile firing weapon and at the same time lets the weapon be aimed and fired in many directions.A turret is a rotating weapon platform...
(a characteristic which it shared with the M10) left the crew exposed to
sniperA sniper is a highly trained marksman who shoots targets from concealed positions or distances exceeding the capabilities of regular personnel. Snipers typically have specialized training and distinct high-precision rifles...
s,
grenadesA hand grenade is an anti-personnel weapon that explodes a short time after release. The French military term grenade probably comes from the shape of the pomegranate fruit, which is also called grenade in French....
and
shell fragmentsFragmentation is the process by which the casing of an artillery shell, bomb, grenade, etc. is shattered by the detonating high explosive filling. The correct technical terminology for these casing pieces is fragments , although shards or splinters can be used for non-preformed fragments...
. The doctrinal priority of high speed at the cost of armor protection thus led to an unbalanced design. The problem of the main gun performance was remedied with High Velocity Armor Piercing (HVAP) ammunition late in the war which allowed the 76 mm gun to achieve greater frontal armor penetration, but this was never available in quantity.
Whilst the M18 was capable of high road speeds this attribute was difficult to use successfully in combat, but along with the high top speed was a commensurate ability to accelerate rapidly and change direction rather quickly. Although sustained travel at road speeds was hardly ever used outside of the allied response during the
Battle of the BulgeThe Ardennes Offensive was a major German offensive , launched towards the end of World War II through the forested Ardennes Mountains region of Belgium , France and Luxembourg on the Western Front...
, most Hellcat crews found the higher speeds especially useful in a sprint to
flankIn military tactics, a flanking maneuver, also called a flank attack, is an attack on the sides of an opposing force. If a flanking maneuver succeeds, the opposing force would be surrounded from two or more directions, which significantly reduces the maneuverability of the outflanked force and its...
German tanks which had relatively slow turret traverse speeds, and such maneuvering allowed the tank destroyer crew a shot instead into the enemy's thinner side or rear armor. In general, Hellcat crews were complimentary of their vehicle's performance and capabilities, but did complain that the open top created a cold interior in the Northern European winter of 1944-'45.
American armoured doctrine was based on utilizing tanks solely in a support and exploitation role usually in conjunction with infantry. Tank destroyers, like the Hellcat, were to be used against tanks. To this end, the Hellcat was not intended to engage in protracted combat and had light armour and extremely high speeds to quickly respond to breakthroughs in the line by German armour. In reality, the opposite was true, as the Sherman ran into encounters with German tanks far more often than intended, and near the end of the war, tank destroyers were increasingly used as
self-propelled artillerySelf-propelled artillery vehicles are a way of giving mobility to artillery. Within the term are covered self-propelled guns and rocket artillery...
in support of infantry for lack of any other targets.
The only M18 variant which was produced in significant numbers was the
Armored Utility Vehicle M39, a turretless variation used to transport personnel or cargo or as a
gun tractorArtillery tractor is a kind of tractor, also referred to as a gun tractor, a vehicle used to tow artillery pieces of varying weights. The first such devices were designed prior to the outbreak of World War I, often based on agricultural machines such as the Holt tractor. Such tractors allowed the...
. This version was armed with a single M2 machine gun on a flexible mount. 650 early production M18s were converted into M39s by removing the turret and fitting seats for up to eight men in the open fighting space. M39s saw combat during the Korean War primarily as armored personnel carriers and munitions carriers, and were finally declared obsolete on February 14, 1957. About 100 M39s were transferred to the West German Bundeswehr in 1956, where they were used to train the reestablished Panzergrenadier armored infantry units.
The M18 continued in production until October 1944, when the war was nearing its end. 2,507 had been produced by that time at a unit cost of $57,500. Though all tank destroyer units were disbanded by the U.S. after the war, surplus M18s continued to see limited service.
Combat Performance
The M18 served primarily in Western Europe, but was also present in the
PacificThe Pacific Theater of Operations was the World War II area of military activity in the Pacific Ocean and the countries bordering it, a geographic scope that reflected the operational and administrative command structures of the American forces during that period...
. However, due to the comparitive rarity and poor quality of Japanese armour it was often used in a fire support role instead of as a tank destroyer.
On September 19, 1944, in the
NancyNancy is a city in the Meurthe-et-Moselle department in north-eastern France, and formerly the capital of the Duchy of Lorraine, and then the French province of the same name.The city is the head of the department...
Bridgehead near
ArracourtArracourt is a commune in the Meurthe-et-Moselle department in north-eastern France....
,
FranceFrance , officially the French Republic , is a country located in Western Europe, with several overseas islands and territories located on other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean...
, the 704th Tank Destroyer Battalion was attached to the 4th Armored Division. Lt. Edwin Leiper led one M18 platoon of C
CompanyA company is a military unit, typically consisting of 75-200 soldiers. Most companies are formed of three to five platoons although the exact number may vary by country, unit type, and structure...
to Rechicourt-la-Petite, on the way to Moncourt. He saw a German tank gun muzzle appearing out of the fog 30 feet away, and deployed his platoon. In a five minute period, five German tanks of the 113 Panzer Brigade were knocked out for the loss of one M18. The platoon remained in their position and destroyed a further ten German tanks, with the loss of another two M18s. One of the platoon's M18s, commanded by Sgt Henry R. Hartman, knocked out six of these and lived to fight another day. Most of the German tanks were
PantherThe Panther was a tank fielded by Nazi Germany in World War II that served from mid-1943 to the end of the European war in 1945. It was intended as a counter to the T-34, and to replace the Panzer III and IV, though it served along with them as well as the heavier Tiger tanks until the end of the...
s.
The M18 Hellcat was a key element during World War II in the
Battle of the BulgeThe Ardennes Offensive was a major German offensive , launched towards the end of World War II through the forested Ardennes Mountains region of Belgium , France and Luxembourg on the Western Front...
. On December 19 and 20, the 1st Battalion of the 506th PIR, was ordered to support Team Desobry, a battalion-sized tank-infantry task force of the 10th Armored Division assigned to defend Noville[3] located north-northeast of both Foy and of Bastogne just 4.36 miles (7 km) away. With just four M18 tank destroyers of the 705th Tank Destroyer Battalion to assist, the paratroopers attacked units of the 2nd Panzer Division, whose mission was to proceed by secondary roads via Monaville (just northwest of Bastogne) to seize a key highway and capture, among other objectives, fuel dumps—for the lack of which the overall German counter-offensive faltered and failed. Worried about the threat to its left flank in Bastogne, it organized a major joint arms attack to seize Noville. Team Desobry's high speed highway journey to reaching the blocking position is one of the few documented cases wherein the legendary top speed of the M18 Hellcat (55 miles per hour (89 km/h), faster than today's M1A2 Abrams) was actually used to get ahead of an enemy force as envisioned by its specifications.
The attack of 1st Battalion and the M18 Hellcat tank destroyers of the 705th TD Battalion near Noville together destroyed at least 30 German tanks and inflicted 500 to 1000 casualties on the attacking forces in what amounted to a spoiling attack. A Military Channel expert historian credited the M18 destroyers with 24 kills, including several Tiger tanks, and believes that, in part, their ability to "shoot and scoot" at high speed and then reappear elsewhere on the battlefield and therefore appear to be another vehicle entirely played a large part in confusing and slowing the German attack, which subsequently stalled, leaving the Americans in possession of the town overnight.
Post War
After World War II, many M18s were given to other countries. These were rebuilt and refurbished by Brown & Root in northern Italy in the late 1940s and early 1950s and bear data plates that indicate those rebuilds. A primary user was
YugoslaviaYugoslavia is a term that describes three political entities that existed successively on the Balkan Peninsula in Europe, during most of the 20th century.The first country to be known by this...
, which kept them in reserve until early 1990s. Most of these vehicles were later used by the
Republic of Serbian KrajinaThe Republic of Serbian Krajina was a self-proclaimed Serbian-dominated entity within Croatia during the 1990s. Established in 1991, it was not recognized internationally...
army during the
Yugoslav warsThe Yugoslav Wars were a series of violent conflicts fought in former Socialist Federal Republic of Yugoslavia during the 1990s and 2001...
. One example was used on an armored train named the
Krajina Ekspres (Krajina Express).
TaiwanTaiwan , also known as Formosa , is the largest island of the Republic of China in East Asia. Taiwan is located east of the Taiwan Strait, off the southeastern coast of mainland China...
also operated several M18s until their chassis and hulls were worn out, at which point the turrets were salvaged and installed onto surplus hulls of
M42 DusterThe M42 40 mm Self-Propelled Anti-Aircraft Gun, or "Duster" as it is known, is an armored light air-defense gun built for the U.S. Army from 1952 until December 1959. Production of this vehicle was performed by the tank division of the General Motors Corporation. It used components from the...
anti-aircraft vehicles to produce Type 64 light tanks.
Prototype variants
- 105 mm Howitzer Motor Carriage T88: M18 with the 76 mm gun replaced with a 105 mm T12 howitzer
A howitzer is a type of artillery piece that is characterized by a relatively short barrel and the use of comparatively small explosive charges to propel projectiles at relatively high trajectories, with a steep angle of descent...
; canceled after the end of the war.
- 76 mm Gun Motor Carriage T86 (Amphibious): M18 with a specially-designed flotation hull, using its tracks for water propulsion.
- 76 mm Gun Motor Carriage T86E1 (Amphibious): Same as T86, but with the addition of propellers for propulsion.
- 105 mm Howitzer Motor Carriage T87 (Amphibious): This model had the 105 mm T12 howitzer of the T88, and like the T86, used its tracks for water propulsion.
All work on the three amphibious models was canceled after the end of the war.
External links