U.S M113 A.P.C

M113 Armored Personnel Carrier

The original M113 Armored Personnel Carrier (APC) helped to revolutionize mobile military operations. The vehicles were able to carry 11 soldiers plus a driver and track commander under armor protection across hostile battlefield environments. More importantly, the new vehicles were air transportable, air-droppable, and swimmable, allowing planners to incorporate APCs in a much wider range of combat situations, including many "rapid deployment" scenarios. The M113s were so successful that they were quickly identified as the foundation for a family of vehicles. Early derivatives included both command post (M577) and mortar carrier (M106) configurations.

Originally, the M113 APC was intended merely as a troop carrier-a means of transport. Doctrine stated that the infantry were to dismount and engage the enemy. It soon became apparent that the firepower of the .50-caliber machine gun, coupled with the vehicle's armor protection and mobility, produced a shock effect on the enemy. Some advisers and commanders realized that since the Viet Cong had no effective weapons to fight armor the M113 could be used as a mounted armored fighting vehicle.

Perhaps the best way to judge the success of the M113 is to examine the enemy reaction to it. The Viet Cong were not prepared for M113's when the South Vietnamese first used them in mid-1962. The Viet Cong doctrine stressed occupation of dug-in positions in the face of APC assaults, and enemy soldiers were soon learning crude methods of destroying the M113. Holes the size of an APC, nicknamed tiger traps by advisers, were soon found in delta roads. Observing the difficulties that APC units had in crossing canals, the Viet Cong used canals as obstacles in their positions, and frequently they mined possible crossing sites.

In 1965 the Viet Cong published a comprehensive and fairly accurate training document entitled Attack on M113 APC. This document listed characteristics of the APC; organization, equipment, and strength of mechanized units; tactics used by APC units; methods of attacking an APC; and some training techniques. Included were instructions for using the new antitank weapons. In the spring of 1963 the Viet Cong had begun to use recoilless rifles with 57-mm. high explosive, antitank rounds, and the number of hits on M113's had increased dramatically by the fall of 1963. Although the rounds often penetrated, they did not usually destroy the M113. Late in that year, armor-piercing .30-caliber ammunition along with a large number of automatic weapons was found in a Viet Cong cache in the delta. The extent of the Viet Cong antiarmor equipment became apparent when, in August 1963, an armor-piercing grenade was discovered. The first 75-mm. recoilless rifle was captured in September, and in December the first M113 was damaged by a 75-mm. round. This arms buildup continued into 1964, when a variety of mines, both pressure and electrically detonated, accounted for the majority of damaged and destroyed vehicles.

By 1965 the Viet Cong was using armor-defeating weapons as low as company level among regular and provincial units. Newly organized weapons platoons, companies, and battalions armed with 57-mm. and 75-mm. recoilless rifles and .50-caliber machine guns were issued the rocket propelled antitank grenade, RPG2. For several years this weapon with its B40 warhead was the principal enemy weapon against armor. Eventually, the RPG2 was replaced by the RPG7, an improved antitank grenade with a more lethal warhead, greater range, and a better sight.

General
Length	191.5"
Width	105.75"
Height	86.5"
Clearance	16"
Weight, combat loaded	27,180 lb. (12,329 kg)
Maximum weight	31,000 lb. (14,061 kg)
Net weight	23,880 lb. (10,832 kg)
Air drop weight	22,128 lb. (10,037 kg)
Personnel capacity	2 + 11
Fuel tank capacity	95 gallons (360 liters)
Ground pressure	8.63 psi (0.60 kg/cm2)
Performance
Speed on land	41 mi/h (66 km/h)
Speed in water, with track	3.6 mi/h (5.8 km/h)
Cruising range	300 mi (483 km)
Turning radius	Pivot to infinite
Slope	60%
Side slope	40%
Trench crossing	66 in. (168 cm)
Vertical wall climbing	24 in. (61 cm)
Braking (20-0 mi/h)	40 ft.
Engine
Make and model	Detroit Diesel 6V53T
Displacement	318 in.3 (5.2 liter)
Fuel	Diesel (DF2)
Rated horsepower	275 hp
Gross horsepower-to-weight ratio	20.2 hp/ton
Transmission, Automatic
Make and model	Allison X200-4B
Type	Hydrokinetic
Steering	Hydrostatic
Brake type	Multiple wet plate
Running Gear
Suspension	Torsion bar
Road wheels	5 per side, 24 inch diameter (61 cm)
Track type	Steel single pin, detachable rubber pad
Number of shoes	63 left, 64 right
Track pitch	6 in. (15.2 cm)
Track width	15 in. (38 cm)
Shock absorbers	3 per side
Wheel travel	9.0 in. (22.9 cm)
Electrical System
Generator
Amperes	200, 300 optional
Volts, dc	28
Batteries	4, type 6TL, 120 amp-hr, 12-volt each
Armament
50 cal MG	2,000 ready rds.
Armor
Basic hull	5083 Aluminum
Bolt-on armor kit	Steel armor
Mine armor	Steel armor
Gun shield kit	Steel armor
Spall suppressant	Composite panel
Fire Extinguishers
Fixed	5 lb. (2.3 kg) CO2 for engine compartment
Portable	5 lb. (2.3 kg) CO2