M48 series of MBT's

Development

In October 1950, Detroit Tank Arsenal began design work on a new tank armed with a 90 mm gun and, in December the same year, the Chrysler Corporation was awarded a letter of intent to design the new tank under the designation T48. Design work began in late December and six prototypes were built, the first being completed in December 1951. In March 1951, before the prototypes had been completed, the Fisher Body Division of the General Motors Corporation and the Ford Motor Company at Livonia were both given a production contract for the tank. Chrysler's first production M48 rolled out of the Delaware Tank Plant and was christened by Mrs George S Patton Junior on 1 July 1952. The first production M48s were completed in 1952 and production of the M48 series amounted to 11,703 units, about 6,000 of which were built by the Chrysler Corporation at the Delaware Tank Plant which continued production until 1959. Alco Products of Schenectady also built a number of M48A2 tanks. Many components of the M48 are also used in the M88 ARV as well as the M53 SPG, and further development of the tank resulted in the M60 series, production of which was finally completed at the Detroit Tank Plant in September 1987. Initial production of the M60 MBT was in fact undertaken at the Delaware Tank Plant but in 1959 a decision was taken that all future production would be undertaken at the Detroit Tank Plant.

Description(M48A3)

The cast hull of the M48 is boat-shaped with additional sections welded into position. A hull escape hatch is provided in the floor of the tank. The turret is a one-piece casting. The driver is seated at the front of the hull in the centre and is provided with a single-piece hatch cover that opens to the right, forward of which are three M27 periscopes. For driving at night, an M24 infrared periscope is placed in the turntable located in the driver's hatch. The other three crew members are in the turret with the commander and gunner on the right and the loader on the left. The commander is provided with an M1 cupola which he can traverse by hand through 360. This cupola is equipped with five vision blocks and an M28C sight for controlling the 12.7 mm (0.50) machine gun. The M28C has a magnification of x1.5 and a 48 field of view. The coincidence rangefinder is operated by the tank commander and has a maximum range of 4,400 m and a magnification of x10. The gunner is seated forward and below the commander and has a roof-mounted periscope sight with a x8 magnification and a telescope with a similar magnification linked to the main armament. The ballistic computer is an electromechanical device which has been designed to compute super elevation angles for the main armament. It receives range information in the form of shaft rotation from the rangefinder. The data are then applied to the ammunition data and ballistic corrections which have been entered into the computer by the gunner. The end product is the super elevation angle which is transmitted through the ballistic drive to the periscope. The ballistic drive also transmits the same super elevation angle to the rangefinder which is operated by the tank commander. The loader is provided with a single-piece hatch cover that opens to the rear. Mounted to the top rear of the turret is a dome-shaped ventilator cover and a stowage basket is provided at the rear of the turret.

The engine is mounted to the immediate rear of the bulkhead separating the engine and fighting compartments and the transmission is at the rear of the vehicle. The engine compartment is equipped with fire extinguishers but there is not a fire warning system. Power is transmitted to the final drives through the cross-drive transmission, which is a combined transmission, differential, steering and braking unit.

The torsion bar suspension consists of six dual rubber-tyred roadwheels with the idler at the front, drive sprocket at the rear and five return rollers on each side. Some earlier versions of the M48 tank were fitted with a tensioning idler between the drive sprocket and the sixth roadwheel station. Hydraulic shock-absorbers are provided for the first, second and sixth roadwheel stations. Infrared driving lights are fitted as standard and most models have an infrared/white light searchlight mounted over the main armament, which has a maximum range of 2,000 m. Standard equipment includes an NBC system, heaters, an external infantry telephone and provision for installing a dozer blade on the front of the hull. The M48, M48C and M48A1 can be fitted with the M8 blade weighing 3,980 kg and the M48A2, M48A3 and M48A5 with the M8A1 blade which weighs 3,810 kg. The tank can ford to a depth of 1.219 m without preparation and to 4.438 m with a deep fording kit. Before deep fording, all the openings are sealed and an exhaust extension is fitted vertically to the right rear engine grille, the bilge pump is switched on. Main armament of the M48A3 is an M41 (T139) 90 mm M41 gun, which consists of the barrel, evacuator chamber, blast deflector and breech mechanism assembly. The breech block is of the vertical sliding type with an inertia percussion firing mechanism. The barrel has a life of 700 equivalent full charge rounds. The following types of fixed rounds can be fired, but it should be noted that not all are currently in use: APERS-T (M580), APC-T (M82), AP-T (M77), AP-T (M318), Canister (M336), Canister (M377), HE-T (M71), HEAT-T (M431), HEAT (M348/M348A1), HVAP-T (M332A1), TP-T (M353) and Smoke WP (M313). A total of 19 rounds of 90 mm ammunition is stowed to the left of the driver with a further 11 rounds to his right, eight horizontally on the turret floor, 16 stowed vertically around the turret ring and the remaining eight for ready use in the turret. Mounted coaxially to the left of the main armament is a 7.62 mm M73 machine gun (earlier models have the 7.62 mm (0.30) M1919A4E1 weapon), and mounted in the commander's cupola is a 12.7 mm (0.50) Browning M2 HB machine gun which can be elevated from -10 to +60, and can be aimed and fired from within the cupola.

Pakistani Variant

M48A5 The Anniston Army Depot converted 2,064 M48A1/M48A3s to M48A5 configuration, with final deliveries taking place in December 1979. Major modifications required to convert an M48A1 to the M48A5 standard were top-loading air cleaner, top deck grille, engine and transmission shroud, gun travel lock, exhaust grilles, power pack (new engine fitted), final drives, tow pintle, engine and transmission mounts, hull turret seal, torsion bar knockout, bulkhead, drain valves, fuel tank and lines, track support rollers and shield, turret basket, modified turret ammunition stowage, T142 track, double bump spring and forward arm, driver's controls, driver's escape hatch, modified hull ammunition stowage, fire extinguisher, hull armour, heater, stowage boxes, driver's periscope, gun shield and cover, turret and gun control, 105 mm M68 gun (as in M60 series), composite headlamp, 2.2 kW searchlight, nylon ballistics shield, M114 mount and M105 telescope and graticule kit, M13B1 quadrant elevation, M10A6 ballistics drive, M32 and M118 periscope mount, M13B1C computer cam kit, M17B1C rangefinder and M28C periscope, M104A1 periscope mount, turret electrical kit, cupola adaptor ring and retaining ring, turret manual drive and traverse gearbox, turret stowage, searchlight stowage and cargo rack screen. Major modifications to convert the M48A3 to the M48A5 are the turret electrical kit, turret stowage, top-loading air cleaner, gun travel lock, solid-state regulator, turret basket, T142 track, ammunition stowage, 105 mm gun, gun shield and cover, M87 gun mount, graticule kit and computer cam kit. The fully enclosed commander's cupola was replaced by an Israeli-designed cupola which was manufactured by Associated Steel Foundries in Israel. First US-produced cupolas were delivered in mid-1976. A 7.62 mm M60D machine gun is mounted externally at the commander's station and there are two mounting positions provided at the loader's hatch for a 7.62 mm M60D machine gun to provide suppressive fire against enemy troop and ATGW positions. These M48A5 have now been phased out of service with the National Guard and some passed on to other countries.

M48 Armoured Vehicle-Launched Bridge This is an M48 with its turret removed and fitted with a scissors bridge launched hydraulically over the front of the vehicle in three minutes. The bridge weighs 14,470 kg, has an overall length when opened out of 19.202 m, can span a gap up to 18.288 m and has a maximum capacity of 60,000 kg. The M48 AVLB has a crew of two and weighs 55,746 kg with the bridge and 41,685 kg without it. Details of the M48/M60 AVLB are given in Jane's Military Vehicles and Logistics 1997-98, pages 133-134. In 1990, the Taiwan (Republic of China) Army purchased 12 M48A5 AVLB systems from Marvin Land Systems, Los Angeles, California. The system consisted of a converted M48A5 tank chassis with the CD-850-6A1 transmission and the AVDS-1790-2D diesel engine, a launching mechanism and the span, Class 60 aluminium scissors bridge. Marvin Land Systems conducted engineering and chassis overhaul and conversion, bridge construction and the assembly and testing of the complete system at its Los Angeles facility.

Status Production complete. Pakistan has 300 of M48A5 all fitted with 105 mm guns.

COMPANY NAME : Chrysler Corporation, Delaware

COMPANY NAME : Ford Motor Company, Michigan

COMPANY NAME : Fisher Body Division of General Motors Corporation, Michigan

COMPANY NAME : Alco Products of Schenectady