Armored Personnel Carriers M113A1
Armored Personnel Carriers M113A1
Except for the power train and fuel tank, the configuration of the M113A1 was identical to the M113. Since there was no ignition switch, a fuel cutoff control was provided to stop the diesel engine. The TX-100 transmission consisted of an hydraulic torque converter with a lock-up clutch and a basic three speed, constant mesh, planetary gear train.
The drive ranges were 1, 1-2, 1-3, neutral, and reverse. It shifted automatically to the appropriate speed in ranges 1-2 and 1-3. Steering was provided by the brake levers on the controlled differential as in the M113.
The personnel heater kit was retained on the M113A1 for cold weather operation, but it no longer supplied hot air for the battery box or the power plant compartment. An engine coolant heater kit warmed and circulated coolant through the engine and the battery box heat exchanger.
A windshield kit was available to protect the driver from cold wind when driving with his head exposed in the open hatch. An M8A3 gas particulate filter unit could be installed to provide purified air to four M14A1 gas masks or four hospital hood protectors when the litter kit was installed.
Experience in Vietnam had shown the value of sprocket mounted capstans on the carriers. Use of these capstans with anchors allowed a bogged vehicle to pull itself out of swampy areas without assistance. In line with this experience, a capstan and marine recovery kit was provided for the M113A1. It consisted of two ground anchors with nylon ropes which wound onto the two capstan drums attached to the final drives.
A machine gun stowage kit allowed the .50 caliber machine gun on the M113A1 to be removed from the commander's cupola and stowed on the top deck. When the machine gun was stowed, a ground laser locator designator (GLLD) was mounted in its place on the cupola. When the GLLD was installed, the cupola was locked to the top deck by the cupola lock kit to prevent any rotation.
The combat weight of the M113A1 increased to over 12 tons with the heavier diesel engine and the 95 gallon fuel capacity. However, the maximum speed was now over 40 miles per hour on level roads. The maximum water speed remained at about 3 1/2 miles per hour.
Production of the M113A1 continued at FMC into 1979 for a total of 23,576 vehicles for the United States and foreign military sales. Additional vehicles were produced for direct sales by FMC.
As a result of experience with mines in Vietnam, a vulnerability reduction kit was developed for the armored personnel carriers. This kit included a steel belly armor plate installed under the front of the vehicle and armored exterior fuel tanks mounted on the rear (U.S. Army).
The fuel lines also were rerouted away from the floor. Buoyancy cells were attached to the trim vane and on each side of the hull front to maintain the vehicle trim when afloat. An emergency ramp release also was provided as well as a shoulder harness for the driver.
Another effort to minimize mine damage resulted in the development of a version of the M113A1 with a double floor during 1968. This increased the height of the vehicle requiring longer road wheel arms and adjustment of the torsion bars to maintain the ground clearance.
However, this version of the vehicle did not enter production. The mine resistant M113A1 with the double bottom can be seen in the two top photographs. Note that the suspension is fitted with track return rollers. At the left, the tall double bottom vehicle can be compared with the standard M113A1.
Low speed and limited maneuverability when afloat were always a problem for the armored personnel carriers M113A1. One attempt to improve the swimming performance resulted in the installation of two water-jet propulsion units on the rear of the personnel carrier. The water-jets were driven by propeller shafts on top of the vehicle. Steering vanes on the water-jets improved the maneuverability in the water, but the new propulsion system was not installed on the production vehicles.
SEARCH BY TAG
make the text more / less