M18 GMC

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RANK 5 FRANCE
Somua SM PACK
M18 GMC
us_m18_hellcat.png
M18 GMC
AB RB SB
5.3 6.0 6.0
Class:
Research:40 000 Specs-Card-Exp.png
Purchase:135 000 Specs-Card-Lion.png
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This page is about the tank destroyer M18 GMC. For the premium version, see M18 "Black Cat". For the upgunned "super" version, see Super Hellcat.

Description

GarageImage M18 GMC.jpg


The M18 Gun Motor Carriage, also known as the M18 GMC, is a Rank III American tank destroyer with a battle rating of 5.3 (AB) and 6.0 (RB/SB). It was introduced in Update 1.49 "Weapons of Victory". The M18 "Hellcat" was the epitome of the American tank destroyer doctrine, it was very fast, very mobile, and has a powerful gun, though with a large trade-off with only 12.7 mm (0.5 inches) of armour.

The M18 "Hellcat" compensates the lack of anti-tank capability on U.S vehicles by having access to a 76 mm gun with APCR ammunition, all in the battle rating of 5.3.. This makes the M18 able to fight off many of the high-ranking vehicles it could face like the Panther D, Tiger H1, KV-1, KV-85, and IS-1.

Unlike the other tank destroyers known 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. Americans tank destroyers also have very high maneuverability compared to other nation's tank destroyers, allowing it to flank the enemy.

The main weak point of 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 would destroy many critical components in the M18 or cripple the crew. The only saving grace with this extremely thin ammunition is that standard AP rounds may overpenetrate the armour, doing minimal damage to the internals. Thus, when facing the M18, its best to use AP rounds with explosive fillers or HE and HEAT rounds while avoiding usage of pure AP rounds and APCR.

General info

Survivability and armour

Armour type:

  • Rolled homogeneous armour
  • 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 the turret rear, granting some 15 mm in thickness.

Mobility

Mobility characteristic
Weight (tons) Add-on Armor
weight (tons)
Max speed (km/h)
17.7 N/A 79 (AB)
72 (RB/SB)
Engine power (horsepower)
Mode Stock Upgraded
Arcade 653 804
Realistic/Simulator 407 460
Power-to-weight ratio (hp/ton)
Mode Stock Upgraded
Arcade 36.89 45.42
Realistic/Simulator 22.99 25.99

Armaments

Main armament

Main article: M1 (76 mm)
76 mm M1
Capacity Vertical
guidance
Horizontal
guidance
Stabilizer
45 -10°/+20° ±180° N/A
Turret rotation speed (°/s)
Mode Stock Upgraded Prior + Full crew Prior + Expert qualif. Prior + Ace qualif.
Arcade 21.13 29.25 __.__ __.__ 41.79
Realistic 14.28 16.80 20.4 22.60 24.00
Reloading rate (seconds)
Stock Prior + Full crew Prior + Expert qualif. Prior + Ace qualif.
7.93 7.02 6.47 6.10
Ammunition
Penetration statistics
Ammunition Type of
warhead
Penetration in mm @ 0° Angle of Attack
10m 100m 500m 1000m 1500m 2000m
M62 shell APCBC 145 142 130 116 103 92
M42A1 shell HE 8 8 7 7 7 7
M79 shot AP 133 131 121 109 98 89
M93 shot APCR 221 215 203 181 154 124
Shell details
Ammunition Type of
warhead
Velocity
in m/s
Projectile
Mass in kg
Fuse delay

in m:

Fuse sensitivity

in mm:

Explosive Mass in g
(TNT equivalent):
Normalization At 30°
from horizontal:
Ricochet:
0% 50% 100%
M62 shell APCBC 792 7.0 1.2 20 63.7 +4° 48° 63° 71°
M42A1 shell HE 800 5.84 0.1 0.5 390 +0° 79° 80° 81°
M79 shot AP 792 6.8 N/A N/A N/A -1° 47° 60° 65°
M93 shot APCR 1,036 4.26 N/A N/A N/A +1.5° 66° 70° 72°
Ammo racks
Ammo racks of the Hellcat.
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) (+36) (+44) No

Machine guns

Main article: M2HB (12.7 mm)
12.7 mm M2HB
Pintle mount
Capacity (Belt capacity) Fire rate
(shots/minute)
Vertical
guidance
Horizontal
guidance
800 (200) 576 -10°/+70° ±60°

Usage in battles

Before all, avoid colorful or bright decals. Camouflage is a main part of the M18's defense. 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 maneuvers and relocate. Not for trying to cross open field, that will leave it open to enemy fire, 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 an 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 have also located the firing spot. If detected, hide immediately and relocate.

Flanking: Flanking is the most dangerous maneuver 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:

  • Outstanding firepower, especially with the availability of APCR ammunition, coupled with the fast reload speed and turret traverse
  • Overall mobility is superb, with very responsive maneuvering that allows the Hellcat to excel in flanking maneuvres
  • Overall construction is low profile, reducing target size
  • The nature of its thin armour means AP rounds have a tendency to pass straight through without damaging modules, and an APHE fuze may not even be triggered.

Cons:

  • Thin armour also means rapid-fire autocannons, heavy machine guns, and aerial weapons could easily shred it
  • Commander is exposed at the 0.50 cal machine gun mount, and knocking him out would render the weapon useless
  • Open-top construction means aerial strikes and artillery could rain havoc onto the crew
  • Standard AP and APCBC round may be inadequate facing against most foes from the front
  • A moment of immobility due to a damaged engine or transmission could be a sign of impending doom for the M18.
  • Hull-break mechanics mean any explosions or well-aimed AP round could instantly destroy the vehicle

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 defense, 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 force. This role led to the desire for a fast vehicle with a powerful gun and mobility. Minimal emphasis was placed on armor, as the doctrinal role of tank destroyers was to respond rapidly to an enemy armored breakthrough; heavy armor 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 a 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.[1]

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 are 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 an 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 were 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 theater was limited due to the inadequate armour of Japanese tanks, it saw most of its service in the European theater 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 are 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 GMCs credited with at least 24 tank kills of the 30 total inflicted in the attack.

Legacy

Overall, the M18 GMCs 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 brethens, 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 unecessary component in the modernizing armoured forces.

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

Media

Skins and camouflages for the M18 Hellcat series from live.warthunder.com.

References

  1. Zaloga Steven. M18 Hellcat Tank Destroyer 1943-97 Great Britain: Osprey Publishing Ltd., 2004

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


USA tank destroyers
M10  M10 GMC
M36  M36 GMC · M36B2
T95  T28 · T95
M109  M109A1
ATGM  LOSAT · M901
Wheeled  M3 GMC · T55E1
Other  M8 HMC · M50 · M56
China  ▃LVT(A)(4) (ZIS-2)