American Army M113A3 armored personnel carrier during exercises in Germany, 2015 year
"Combat buses." The American armored personnel carrier M113 became the most massive armored personnel carrier in stories. Adopted in the 1960 year, the caterpillar combat vehicle is still used in the armies of many countries. Moreover, the design turned out to be so successful that it served to create various specialized military equipment: from anti-aircraft self-propelled guns and staff vehicles to self-propelled mortars and flamethrowers. In total, since 1980 of the year, more than 80 thousand M113 armored personnel carriers and other combat vehicles built on its base have been assembled. For example, the Soviet BTR-60, created at the same time, sold around the world with a series from 10 to 25 of thousands of cars.
Among other things, the M113 tracked armored personnel carrier was the first combat vehicle in the world whose body was made entirely of aluminum. The use of aluminum armor allowed to reduce the weight of the combat vehicle, while maintaining an acceptable level of fire protection from the rifle weapons. At the same time, the armored personnel carrier is still in service with the American army, where the timing of its replacement is constantly shifting. The U.S. military expects to completely abandon this machine in all divisions before the 2030 year, that is, 70 years after adoption.
The need for a new armored personnel carrier in the United States was recognized during the rearmament of the ground forces with new models of military equipment. After the end of World War II, lungs were adopted in the USA. Tanks M41 Walker Bulldog, medium tank M48 Patton III, heavy tank M103, which was in service with the Marine Corps, as well as new anti-tank self-propelled guns M56 Scorpion and other models of military equipment. Under these conditions, the military also wanted to get a new armored personnel carrier, which could be used as a universal machine, and which would meet new technological requirements and its time.
Work on the new machine was launched in the 1950-s with the development of tactical and technical requirements. The future vehicle was based on the principle of a “combat taxi” or “combat bus”. It was planned to create an armored vehicle with a closed hull, which could deliver a motorized rifle squad to the battlefield. Dismounted, the paratroopers immediately had to engage in battle with the enemy. Based on a certain concept, a number of requirements were presented to the new BTR: air transport; the ability to overcome deep water barriers; large power reserve; the possibility of transporting an infantry squad; good protection; high cross. Separately, the high versatility of the machine was stipulated due to the ease of adaptation of the self-supporting body of the armored personnel carrier to the solution of certain tasks needed by the military.
In 1956, engineers of the American company Food Machinery Corporation (FMC), who had extensive experience in the development and production of such equipment, began to create a new APC. Back in the early 1950's, the company created successful models of tracked armored personnel carriers, in which the future M113 was easily guessed. These were the M75 armored personnel carrier, which took part in the war in Korea, and the more advanced amphibious M59. The latter, in addition to the ability to swim, was smaller and turned out to be significantly cheaper in production. Prior to 1960, the M59 armored personnel carrier was released in an impressive series - more than 6 thousand vehicles.
For testing, the company prepared two main prototypes, including the T113 with aluminum plate armor. For production, a special aviation aluminum, which was not inferior in strength to steel. Two copies were presented with light and heavier aluminum armor. The second version was the prototype T117, which differed only in a steel case. Tests have shown that the T113 with thick aluminum armor at a lower weight than the T117, provides the same level of protection for the crew and the landing, so the military chose this model. After improvements in 1960, an improved version of the T113E1 armored personnel carrier was officially adopted by the U.S. Army under the designation M113. Initially, it was a gasoline powered combat vehicle, but already in 1964 it was supplanted from mass production by the T113E2 model, adopted for service under the designation M113A1. On this armored personnel carrier a more advanced diesel engine was installed.
M113 Prototype - T113
Created at the turn of the 1960's, a light floating tracked armored personnel carrier (only the first modifications were floating) turned out to be a very successful machine that could carry a crew of two people and up to 11 infantry in full gear. In the future, the armored personnel carrier became the basis for dozens of different specialized combat vehicles, and also was repeatedly modernized. Three major machine upgrades are known - M113A1, M113A2 and M113A3, the last of which was carried out in the year 1987.
Technical features of the M113 armored personnel carrier
The layout of the American armored personnel carrier M113 is traditional for most tracked armored personnel carriers and infantry fighting vehicles from different countries. The transmission and engine are located in the front of the case, the place of the mechanical drive from the axis of the case is shifted to the left. The armored personnel carrier commander, who also holds the role of gunner, sits in the center of the combat vehicle, he has at his disposal a turret to monitor the situation. In the landing compartment in the rear of the hull there are places for 11 infantrymen. 10 of them are sitting on hinged benches along the sides facing each other, the 11 paratrooper is sitting on the hinged seat facing the exit ramp through which soldiers left the car. The engine-transmission compartment is separated from the remaining compartments of the combat vehicle by a special firewall, while the crew and the landing can freely move between the compartments.
The body of the armored personnel carrier is made of aluminum armor (a special alloy with the addition of manganese and magnesium) by welding. The case itself is a box-shaped design that awarded the BTR with a recognizable silhouette. The thickness of the body armor is from 12 to 44 mm. The frontal part consists of two armor plates with a thickness of 38 mm, the upper of which is located at an angle of 45 degrees to the vertical, the bottom - 30 degrees. The sides are arranged vertically, their upper part has a reservation of 44 mm. The initial version of the reservation provided protection for the landing party and crew from the fire of 7,62-mm small arms and fragments of shells and mines; in the frontal view, the armor kept the 12,7-mm armor-piercing bullets hit from a distance of up to 200 meters.
The chassis of the M113 armored personnel carrier externally remained unchanged during the entire production of the combat vehicle. For one side, it consists of five double rubberized road wheels, a double rubberized sloth and a double drive wheel. Suspension of all rollers torsion, individual. On the 1960 base model of the year, only the first and last track rollers on each side of the combat vehicle were equipped with shock absorbers.
The M113 was powered by a Chrysler 8M V75 8 gasoline-powered 209 cylinder engine. This power was enough to disperse an armored personnel carrier with a combat mass of 10,2 tons to 64 km / h when driving on a highway, a car could reach a speed of 5,6 km / h afloat. The movement on the water surface is carried out by rewinding the tracks. Cruising on the highway was estimated at 320 km.
The M113 armored personnel carriers installed the well-proven large-caliber 12,7-mm Browning machine gun M2NV, which the designers placed next to the commander’s turret. Machine gun fire could be conducted not only on ground, but also on air targets. The transportable ammunition of the machine gun consisted of 2000 cartridges. At the same time, the paratroopers could not fire at the enemy, since there were no loopholes on the sides of the hull for firing from personal weapons.
The main modifications of the M113 armored personnel carrier
The need to upgrade a new armored personnel carrier arose quickly enough. Already in September of 1964, the United States began to mass-produce a new version, which received the designation M113A1. The new combat vehicle was very close to the model adopted in the 1960 year, differing primarily in the new engine - a diesel engine, as well as a transmission. Armored personnel carriers of this modification received the 6V-53 Detroit Diesel engine, which develops maximum 215 horsepower. at 2800 rpm. Also, the combat vehicle received a new transmission manufactured by General Motors; together with a diesel engine, it made up a single power unit. The use of a diesel engine increased the fire safety of the armored personnel carrier, while the new engine also provided fuel economy. Together with the installation of new fuel tanks, the capacity of which increased to 360 liters, these steps allowed to bring the maximum range of approximately 480 kilometers. At the same time, the modernization led to an increase in the combat mass of the armored personnel carrier by approximately 900 kg, which did not affect the mobility of the combat vehicle due to the compensation of a larger engine with power.
The following updates affected the tracked armored personnel carrier in the 1979 year. The new model received the M113A2 index. The program for creating this model was primarily aimed at improving the reliability and operational characteristics of a combat vehicle. The main changes concerned the suspension and engine cooling system. The new hydromechanical transmission provided the BTR with six speeds forward and one backward (on the previous 3 + 1 model), the use of torsion shafts of increased strength increased the ground clearance of the machine from 400 to 430 mm, and bringing the total number of shock absorbers to six (shock absorbers appeared on the second rollers) a positive effect on the smoothness and ease of movement over rough terrain. Also, optionally, two external fuel tanks could be installed on the armored personnel carrier, which were located on both sides of the rear ramp. Especially for the M113A2, a smoke grenade launcher kit was also developed. With all the changes, the model began to weigh 11,34 tons and almost completely lost buoyancy.
Armored personnel carrier M113 and M113 ACAV (armored assault vehicle) in Vietnam
The last large-scale modernization of the M113 occurred in the 1987 year, the updated model was designated M113A3. The main innovations concerned the increased security of the crew and the landing force and took into account the experience of conducting recent local conflicts, including in the Middle East. In the course of work on this model, the designers managed to significantly improve the performance of armor protection and mobility of the combat vehicle. To increase the security of the landing party and the crew, additional steel armor plates were played, which were installed on the main aluminum armor of the hull in the form of additional screens, a bolted connection. The use of mounted armor provided circular protection of the machine from the fire of 14,5-mm heavy machine guns, and in the frontal projection, armor from a distance of 200 meters withstands hit of 20-mm armor-piercing shots to automatic guns. In addition, anti-shatter lining made of composite material, which protects the soldiers from fragments of flying main armor, contributed to increasing the protection of the landing. With additional steel sheets, the bottom of the hull was reinforced. Two external armored fuel tanks were finally registered in the stern of the combat vehicle, replacing the tank located inside the hull. At the same time, the dimensions of the armored personnel carrier also changed, which has grown in length by 44 cm. The solution with the removal of fuel tanks from the hull increased the survivability of the crew and the landing force.
As a result of all the changes, the combat weight of the M113A3 has grown almost to 14 tons (without additional armor 12,3 tons). The increase in the combat weight of the machine required designers to increase the power of the installed engine. The power plant has been seriously changed. The heart of the new model is the turbocharged 6V-53T Detroit Diesel diesel engine. Its power increased to 275 hp, while the designers managed to reduce fuel consumption by 22 percent. Due to the increase in power, the armored personnel carrier not only retained high-speed characteristics, but also seriously added to the dynamics and acceleration. With a new engine up to 50 km / h, the combat vehicle accelerated in 27 seconds instead of 69 seconds in previous versions. In addition, the comfort of the driver, who controlled the armored personnel carrier not with levers, but with a car steering wheel, improved.