M24 (TL)

This page is about the American light tank M18 GMC. For other versions, see M18 Hellcat (Family).

M18 GMC

M18 GMC

Description

In response to the threat of German armoured units that contributed to the Fall of France, the United States developed the Tank Destroyer Branch whose purpose was to help squash armoured breakthroughs from expanding past the front lines. As part of their role, the branch required combat vehicles that were well-armed and were mobile enough to respond to any strategic events. Making do with interim vehicles like the M3 GMC and M10 GMC, the ideal project to develop a vehicle for this role was the T70 by Buick, a fast tank destroyer armed with a 76 mm gun. The vehicle was approved and put in production in Summer 1943 as the M18 GMC and was also associated by its manufacturer's nickname "Hellcat". Though not as numerous as its interim counterparts, the M18 became one of the primary arms of the tank destroyer branch, with its firepower and mobility coming to play in several key battles in the European Theater such as the Battle of the Bulge.

Introduced in Update 1.49 "Weapons of Victory", the M18 "Hellcat" was the epitome of the American tank destroyer doctrine. It is very fast, very mobile, and has a powerful gun, though with a large trade-off of only 12.7 mm (0.5 inches) of armour. Unlike many other tank destroyers in the game, the M18 "Hellcat" has access to a 360° traversable turret, allowing players to have a greater arc of fire than a typical casemate tank destroyer like the StuG III, but at the expense of a slightly higher profile. American tank destroyers also have very high manoeuvrability compared to those of other nations, allowing it to flank the enemy. The main weak point of the M18 is its very thin armour, a feature that actually allows the M18 to reach its high speed. The thin armour makes it possible for any enemy tanks to penetrate the vehicle, a single hit destroying many critical components in the M18 or crippling the crew. The only saving grace with this extremely thin armour is that standard AP rounds may over-penetrate the armour, doing minimal damage to the internals.

Although it is most recognized for its role as a tank destroyer, it was recategorized as a light tank during Update "Ixwa Strike" on 7 May 2021.

General info

Survivability and armour

Armour type:

• Rolled homogeneous armour (hull, turret)
• Cast homogeneous armour (gun mantlet)

Armour	Front (Slope angle)	Sides	Rear	Roof
Hull	12.7 mm (39-64°) Front glacis 12.7 mm (23-52°) Lower glacis	12.7 mm (23-26°) Top 12.7 mm Bottom	12.7 mm (12°) Top 12.7 mm (36°) Bottom	8 mm
Turret	25.4 mm (15-26°) Turret front 19 mm + 25.4 mm (0-55°) Gun mantlet	12.7 mm (1-21°)	12.7 mm (7°)	N/A Open-top 8 mm Bustle and Front

Notes:

• Suspension wheels and tracks are 15 mm thick.
• Belly armour is 5 mm thick.
• The hull underside right above the tracks are only 8 mm thick.
• Tracks are attached the turret rear, granting some 15 mm in thickness.

Mobility

Game Mode	Max Speed (km/h)		Weight (tons)	Engine power (horsepower)		Power-to-weight ratio (hp/ton)
	Forward	Reverse		Stock	Upgraded	Stock	Upgraded
Arcade				713	878
Realistic				407	460

Modifications and economy

As with every ground vehicle, Parts and FPE are an absolute top priority. Following that, depending on player preferences, one of 3 should be researched: Horizontal Drive (close-range, flanking), Suspension (medium-range) or Adjustment of Fire (long-range of a typical engagements). Following this the goal is to get rank IV mobility improvements in order Filters -> Engine -> Transmission. On rank III, along the way, the Crew Replenishment should be prioritized, as its an open-top vehicle, so it will suffer significant causalities from enemy airplanes. If your preferred engagement range is above 700 m then the Elevation Mechanism should be researched. Otherwise: Mobility upgrades are the most important, shells are the lowest priority, as even the situational advantage of the M93 shot is not worth researching over improved mobility, or even accuracy.

Armaments

Main armament

The 76 mm M1 is an extremely capable gun with a high damage potential and a very good gun handling. It can be found on tanks used up to battle rating 6.0, making it one of the most widely used guns throughout the battle ratings and with M18 being the first tanks to use it - it gives it a very high staying power throughout battle ratings. Once upgraded, the turret has very fair guidance in both: horizontal and vertical axis allowing to quickly catch pot-shots, though given exceptional mobility of the platform even it struggles to catch up with the near-instant hull rotation.

76 mm M1					Turret rotation speed (°/s)					Reloading rate (seconds)
Mode	Capacity	Vertical	Horizontal	Stabilizer	Stock	Upgraded	Full	Expert	Aced	Stock	Full	Expert	Aced
Arcade	45	-10°/+20°	±180°	N/A	22.8	31.6	38.4	42.5	45.2	7.93	7.02	6.47	6.10
Realistic					14.3	16.8	20.4	22.6	24.0

Ammunition

• M79 shot - AP - Stock round, has decent penetrative power but no explosive filler. Replace with the M62 shell as soon as possible.
• M42A1 shell - HE - The best round for dealing with unarmoured targets or unarmoured sections of vehicles. It should be used carefully, as everything over 10 mm armour can negate its effects. Typically M62 is superior.
• M62 shell - APCBC - The best anti-tank shell. It has very good penetration and an excellent post-penetration effect.
• M93 shot - APCR - Round trades a significantly lower post-penetration effect for a 20% increase in penetration and flatter flight path.

Penetration statistics
Ammunition	Type of warhead	Penetration @ 0° Angle of Attack (mm)
		10 m	100 m	500 m	1,000 m	1,500 m	2,000 m
M79 shot	AP	134	132	121	109	99	89
M42A1 shell	HE	16	16	14	13	11	10
M62 shell	APCBC	149	146	133	119	106	94
M93 shot	APCR	190	186	167	146	128	112

Shell details
Ammunition	Type of warhead	Velocity (m/s)	Projectile mass (kg)	Fuse delay (m)	Fuse sensitivity (mm)	Explosive mass (TNT equivalent) (g)	Ricochet
							0%	50%	100%
M79 shot	AP	792	6.8	-	-	-	47°	60°	65°
M42A1 shell	HE	823	5.84	0.2	0.1	390	79°	80°	81°
M62 shell	APCBC	792	7	1.2	14	63.7	48°	63°	71°
M93 shot	APCR	1,036	4.22	-	-	-	66°	70°	72°

Smoke shell characteristics
Ammunition	Velocity (m/s)	Projectile mass (kg)	Screen radius (m)	Screen deploy time (s)	Screen hold time (s)	Explosive mass (TNT equivalent) (g)
M88	274	3.44	13	5	20	50

Ammo racks

Ammo racks of the M18 GMC

Full ammo	1st rack empty	2nd rack empty	3rd rack empty	4th rack empty	5th rack empty	Visual discrepancy
45	37 (+8)	27 (+18)	17 (+28)	9 (+36)	1 (+44)	No

Notes:

• Turret empty: 37 (+8) shells.
• When fighting in downtiers it's best to take only 17 shells, which allows the turret and sides of the tank to be empty of shells, notably increasing survivability. Otherwise, it doesn't matter how many rounds are loaded, as most hits against the tank will prove deadly regardless.

Machine guns

12.7 mm M2HB
Mount	Capacity (Belt)	Fire rate	Vertical	Horizontal
Pintle	800 (200)	576	-10°/+70°	±60°

Usage in battles

Before all, avoid colourful or bright decals. Camouflage is the main part of the M18's defence. Chances for good performance in battle are: be "invisible", fast and effective.

The M18's speed is its best ally. This speed has to be used for flanking manoeuvres and relocating, but not for crossing an open field; that will leave it open to enemy fire. Simply put: speed is not a substitute for armour.

Relocate:

• This movement will have to be done again and again. Choose a good spot wisely, remove the foliage if necessary to get a clear field of fire. When in the fire spot, use the gun depression and stay in a hull-down position until a target is located. Once a target is locked on, aim at critical components. Try to immobilize the enemy by firing at the engine or transmission, or remove their firepower by shooting the gun or breech, or for instant destruction with a shot to the ammo storage. The last option can work very well or not, as skilled players only carry a few rounds of ammo.

• If positive that the enemy hasn't discovered the firing spot, go for another shot. Stay attentive that none of the enemy's teammates has also located the firing spot. If detected, hide immediately and relocate.

Flanking:

• Flanking is the most dangerous manoeuvre of all because the vehicle will have to be exposed as it moves to the enemy's rear, but it is very effective when it's coordinated with other vehicles. A distraction is needed to gain the enemy's attention while the M18 makes its move. Isolated enemy units are very vulnerable to this tactic. Using the M18 speed to get to the rear and as the enemy heads toward the objective, the firing perspective should give a very clear view of the enemy's side armour. A good shot with the M62 APCBC shell could knock out the enemy rather quickly, but if using solid AP shots like the M79, aim at critical components on mobility and firepower before knocking out the crew or ammo stowage.

Avoid flat terrain

• Flat terrain means that the Hellcat will become an easy target for virtually any vehicle by exposure, especially when not moving or when moving in a straight line. Open plains are the bane of the Hellcat. Whenever possible, one should try to stay amongst hills.

Pros and cons

Pros:

• Overall mobility is superb, with very responsive manoeuvring that allows the Hellcat to excel in flanking manoeuvres
• Fast reload speed and turret traverse
• APCBC round has great penetration and lots of explosive filler, rarely requiring more than one penetrating shot to kill common tanks like M4 Sherman (Family), Cromwell (Family), Tiger H1/E or Panther
• Low profile, reducing target size and allows it to hide behind small bushes or rocks easily
• Thin armour can be a boon: most AP and some APHE shells will simply pass through without causing significant damage
• The M18 is very good at climbing hills, particularly at steep angles
• Speed works well with the scouting mechanic and providing assistance in repairing friendly vehicles

Cons:

• Thin armour means rapid-fire autocannons, heavy machine guns, and aerial weapons will easily disable it
• Commander is exposed at the 0.50 calibre machine gun mount; and knocking him out will neutralize the weapon
• Open-top construction leaves it vulnerable to aerial strikes and artillery
• Gun has poor penetration in an uptier, often can't penetrate anything frontally unless hitting a weak spot. The Ho-Ri, Tiger II (H) and M26 are frontally immune to this 76 mm M1
• If unable to move, the M18 is unlikely to survive concentrated fire
• HEAT or HE shells can cause the vehicle to be over pressurized and destroy the vehicle instantly, even if it wasn't aimed at a critical spot

History

US Tank Destroyer Doctrine

The self-propelled anti-tank doctrine established by the US military called for fast, powerful vehicles able to stop the German blitzkrieg tactics by ambushing the attacking tank forces. This doctrine, known as the "Tank Destroyer Doctrine", called for anti-tank forces to be held in reserve to blunt the massed Panzer attacks that many in the War Department believed was the key to German victory in France in 1940. The concentration of antitank weaponry away from the frontline was eventually determined to be an unnecessary weakness, and the solution was to keep a few anti-tank guns in the front-line as the first defence, while a large reserve of mobile tank destroyers would move in at the location where a German tank breakthrough is happening to ambush and destroy the enemy forces. This role led to the desire for a fast vehicle with a powerful gun and mobility. Minimal emphasis was placed on armour, as the doctrinal role of tank destroyers was to respond rapidly to an enemy armoured breakthrough; heavy armour would only hinder a timely response. The development of a purpose-built tank destroyer languished in bureaucratic limbo for the early years of the war (a delay caused by poor designs such as the M5 Cletrac and bureaucratic infighting between the various departmental cliques), and consequently, the majority of self-propelled tank destroyers were expedients derived from the M4 Sherman chassis. The most common tank destroyer was the M10 GMC, made from the M4 Sherman hull and armed with a 3-inch M1918 gun. Although perfectly capable and welcome addition for frontline forces, it was no faster than an ordinary Sherman tank. The tank destroyers would in 1944 finally receive their purpose-built self-propelled tank destroyer in 1944: the M18 Hellcat.

Development

The origin of the M18 design came as early as December 1941 with the requirement of a Christie suspension and a 37 mm gun. This requirement called for a radical new tank design rather than a derivative of the M4 Sherman. These requirements changed as the war progressed, the first change was to the new and innovative Torsion bar suspension from Buick Motor Division from General Motors and another change was to mount the British QF 6-pounder gun then in use on their Churchill Mark III tanks, the developed prototype vehicle was called the T49 GMC. Then the US Army wanted the heavier 75 mm gun used on the Shermans on it, this prototype was designated the T67 GMC. Finally, the army decided to mount the 76 mm gun also in development for the Sherman onto the prototype, now known as T70 GMC. Changes to hull shape and turret took place to accommodate all these new requirements and armament, but it eventually was approved for service and finally renamed as the M18 GMC and started production in mid-1943, which went on until ending in October 1944 with 2,507 units produced. A variant called the M39 Armored Utility Vehicle was also produced, its turret was removed for space for cargo, 8 personnel, or to tow guns.

Combat usage

These vehicles saw combat debut in the summer of 1944, where they are given the unofficial nickname "Hellcat" by the crews using them. Unlike the M10 tank destroyer that was built before it, the M18 GMC was purely made for emphasis on speed. Armour was restricted down to a maximum of 1-inch (25 mm) on the turret front while the rest of the body plating is a measly .50-inches thick (12.7 mm). The turret was also an open-top design similar to the M10 tank destroyer, meaning the crew are left exposed to the elements and enemy fire and shrapnel. These faults were mitigated by the fact that as its role as a tank destroyer, it was to have minimum contact with infantry and ambush enemy tanks in concealed position rather than face them in an offensive operation. Nevertheless, the M18 GMC was well-liked by the crew for its 76 mm cannon, which allows it to destroy the newer German Tiger Is and Panthers tanks from the front with HVAP ammo (though the Panther at close range only) when unable to flank around to the side or rear of these tanks. The speed was also astounding, reaching 55 miles per hour maximum, this makes the M18 GMC the fastest armoured fighting vehicle in World War II.

While use in the Pacific theatre was limited due to the inadequate armour of Japanese tanks, it saw most of its service in the European theatre against Nazi Germany. Due to the lack in armour and emphasis on speed, the M18 crews utilize the "shoot and scoot" tactic in attacking the enemy from one position and quickly move to another before the enemy could find their initial firing position, this tactic confuses the German tanks, and could even lead them to believe there is more armoured enemy than what it appears. The M18 GMCs were present during the Battle of Arracourt in France as the 704th Tank Destroyer Battalion. Lt. Edwin Leiper led an M18 platoon of C Company and in the battle knocked a total of 15 German tanks for the loss of three M18; six of these German tank kills, most of which were Panthers, were credited to one M18 led by Sgt Henry R. Hartman. The M18 also played a crucial part in the Battle of the Bulge, where its top speed of 55 mph was finally put to good use in bypassing the enemy forces. Four M18 tank destroyers of the 705th Tank Destroyer Battalion assisted the 506th Parachute Infantry Regiment in attacking the 2nd Panzer Divison and their support to kill the fuel lines to the German tanks. The overall attack had the M18 GMC credited with at least 24 tank kills of the 30 total inflicted in the attack.

Legacy

Overall, the M18 GMC proved itself by having the highest kill-to-loss ratio to any other tanks and tank destroyer in American service, making it the most effective tank destroyer in American service. However, like its other tank destroyer brethren, it soon found itself obsolete along with the entire tank destroyer doctrine. Mainly due to increasing prevalence of well-armoured tanks that could do its job more efficiently such as the M26 Pershing, but also the lack of German AFVs at the time of the war and a study on ammo usage indicates that the tank destroyers spent more time supporting infantry with high-explosive shells than killing tanks with armour-piercing, rendering the anti-tank section an unnecessary component in the modernizing armoured forces.

Today, some countries in the world such as Yugoslavia still have the M18 Hellcats in reserves.

Archive of the in-game description

A self-propelled artillery/tank destroyer mount based on the M24 tank. It was part of the American arsenal during World War II. It was produced from the middle of 1943 to October, 1944 and was used in combat operations in Italy and northern Europe. Its primary gun was the M1 76 mm cannon, as was the case with late-model Sherman tanks. This tank destroyer featured very light armour, but the M18 was nevertheless the fastest armoured vehicle in World War II. The Hellcat was the most effective anti-tank SPG in the American army despite its extreme vulnerability and the fact that its 76 mm cannon was unable to penetrate the armour of late German tanks. The vehicle stood out for its speed and manoeuvrability. Able to accelerate and change direction quickly, the Hellcat could easily outflank German tanks or even get behind them, whereas the rotation speed of the German tanks was not fast enough to attack the M18 and the M1 cannon could penetrate the enemy's weak points with relative ease.

Media

Skins

• Skins and camouflages for the M18 GMC from live.warthunder.com.

Videos

The Shooting Range #314 - Metal Beasts section at 00:28 discusses the M18 GMC.

M18 "Hellcat" - Why everyone plays (and likes) it? [review] - HowToPlay1337

M18 Hellcat Supplemental - rob762x51

See also

Links to the articles on the War Thunder Wiki that you think will be useful for the reader, for example:

• reference to the series of the vehicles;
• links to approximate analogues of other nations and research trees.

External links

• [Profile] M18 Gun Motor Carriage – Hellcat
• [Vehicle Profile] As fast as deadly: The M18 Hellcat
• [Devblog] M18 and M18 'Black Cat'

References

Buick Division of General Motors
Tank Destroyers	M18 GMC · M18 "Black Cat" · Super Hellcat
Export	␗M18 GMC · ▄M18
Note	Buick is a division of General Motors (GM).