The M728 Combat Engineer Vehicle (CEV) is a United States Army engineering vehicle originally built in 1965 from a modified M60A1 chassis. Each of the 291 CEV's that were placed in production were equipped with a hydraulically operated debris blade or Trackway Mine Plough, a 165mm turret mounted demolition gun, and a retractable A-frame boom and winch. The demolition gun is designed to be elevated or depressed for use at various ranges up to 925 meters (though I have seen accuracy at over 1200 meters) and is coaxial mounted with a 7.62 mm (.30 cal.) machine gun. A separate .50 cal. is mounted on the cupola.

Used exclusively by combat engineers, the CEV's 165mm demolition gun does not fire your typical tank round. The rounds, weighing over 70 lb (~40lb of which is C-4), are more like tossed grenades than large bullets. When fired, you can see the massive round flying through the air in a high arc, landing with a huge explosion. The big gun's primary purpose is for clearing obstacles such as walls, fences, roadblocks, bunkers, etc or for destroying buildings. It is not effective at anti-personnel or anti-tank warfare. However, when firing one of these rounds, all hatches must be closed as the blast radius can be larger than the effective range of the gun!

Besides destroying obstacles, combat engineers also build them. While not its primary function, the dozer blade in the front can be used to dig trenches when required. The vehicle is also used in breaching, transportation of demolition teams, and pioneering operations. It can even be used as an emergency mechanic vehicle, as the boom and winch are strong enough to lift the huge diesel engines out of any tank. The concept behind the creation of the CEV was to "provide Engineers in the forward combat area with a versatile, armor-protected means of performing mobility tasks under hostile fire. Tasks include reduction of roadblocks and obstacles; filling craters, ditches and short dry gaps; limited construction of combat trails; construction of obstacles; and clearing of rubble and debris."

The CEV has seen combat in Vietnam and Operation: Desert Storm, and while they are slowly being phased out of active use, they are still in use in Germany and South Korea. During Desert Storm the M728 proved unable to keep pace with the M1A1 Abrams, and were often left behind after their mission had been completed rather than slow the convoy.

Crew

It takes a crew of four to run the CEV. Unlike modern battle tanks, the CEV relies on the experience and skills of its crew rather than computers and lasers for targeting.

  • Tank Commander (TC) - Located in the right-rear of the turret, the tank commander usually stands on his seat so that he can keep his head out of the hatch for maximum visibility. It is the tank commander's responsibility to navigate for the driver, call out targets and ranges to the gunner, and communicate over the radio with other members of the unit.
  • Gunner - Located in the right-front of the turret, the gunner is in charge of locating the targets called out by the TC. The gunner must do this with a series of periscopes which is his only view of the outside world.
  • Loader - Located in the left-rear of the turret, the loader's sole job is to load the 70 lb rounds into the demolition gun. It can be a very difficult task to maneuver the rounds from their storage rack in such an enclosed environment.
  • Driver - Located in the front-center of the vehicle's hull, the driver controls the speed and direction of the CEV with controls very similar to a car - steering wheel, gas and brake pedals, etc.

When required, such as during a chemical or biological attack, or when under small arms fire, the crew can close all hatches and perform any of their tasks through periscopes similar to those used by the gunner.

Technical Specifications

General

Date of first acceptance: 1965
Total acceptances: 291
Manufacturer: Detroit Tank Arsenal

Dimensions and Measurements

Weight: 11500 lb (52270 kg)
Length: 353" (8.97m)
Height: 127" (3.23m)
Width: 146" (3.71m)
Ground Clearance: 15.3" (38.9cm)
Winch and A-Frame Lifting Capacity: 17500 lb (7955 kg)
Width of Plough: 208" (5.30m)

Armament

Main Armament: 165mm HEP
Secondary Armament: One M85 .50 cal. MG and one M73 7.62mm MG

Armor

Assembly: Welding
Hull: Rolled homogeneous steel
Upper Front: 4.29" (10.9cm) thick
Lower Front: 5.63" to 3.35" (14.3cm to 8.51cm) thick
Sides: 1.41" to 2.9" (3.58cm to 7.4cm) thick
Top: 1" (2.5cm) thick
Turret: Cast homogeneous steel
Gun Shield: 5" (13cm) thick
Front: 10" (25cm) thick
Sides: 5.5" (14cm) thick
Rear: 2.25" (5.72cm) thick

Performance

Note: These performance specifications are general, safe recommendations. These vehicles are commonly pushed past these limits.

Max level road speed: 30mph (48kph)
Max Trench Crossing: 102" (259cm)
Max Incline Climb: 60°
Max Vertical Obstacle: 24" (61cm)
Min Turning Diameter: Pivot
Max Fording Depth: 48" (120cm)
Cruising range: ~280mi (~450km) on paved roads

Automotive

Engine: Continental AVDS-1790-2A; 12 cylinder, turbocharged diesel
Horsepower: 750 @ 2400rpm
Fuel capacity: 375gal (1420L) diesel
Transmission: Allison CD-850-6A, two ranges forward, 1 reverse
Steering: Mechanical, T-bar
Brakes: Multiple disc

Suspension

Type: Torsion bar
Road wheels: 6 individually sprung dual per track
Track return rollers: 3 dual per track
Drive sprockets: 11-tooth rear drive
Idlers: Dual compensating at front of track
Shock Absorbers: On first 2 and last road wheels per track

Track

Center guide, double pin, rubber chevron; Width 28" (71cm) -OR-
Center guide, double pin, steel with detachable rubber pad; Width 28" (71cm)

Other Combat Engineering Vehicles

Side note: CEV's were blamed by conspiracy theorists for causing the 1993 fire at the Branch Davidian compound in Waco, Texas. There is no doubt that they were present at the time of the fire, however from my experience with CEV's there is no possible way that they were used. The compound would not have had a chance to burn, as it would have been scattered across central Texas.


References

  • At various times, I performed the functions of driver and loader on a CEV in Korea.
  • http://afvdb.50megs.com/usa/cevm728.html
  • http://www.soft.net.uk/entrinet/armour9.htm
  • http://www.globalsecurity.org/military/systems/ground/m728.htm
  • http://www.mindef.gov.sg/army/engi_equip_cev.htm