M9 Armored Combat
The M9 ACE is a full-tracked, relatively fast armored earthmover capable of constructing weapons positions, building or clearing obstacles, and recovering other vehicles in combat areas.
The ACE is a combination of a bulldozer and a front-end loader, with the blade forming the front of a large “bowl” that holds up to 237 ft2 (6.7 m2) of fill.
The top corners of the dozer blade are mounted on heavy arms that lower the blade for dozing and raise it to expose the bowl for loading. The vehicle’s hydro-mechanical suspension can tilt fore and aft or 5° toward one corner of the blade; dozing leverage can be increased by placing ballast in the bowl.
The engine is in the right rear with the driver seat to its left. A heavy armored cupola with vision blocks and a hatch protects the driver under fire. When overhead protection isn’t necessary, the hatch pivots up and back to allow the driver to sit up.
The M9 is fully amphibious in all but fast-running rivers and can be airlifted by the C-130 Hercules and larger transport aircraft.
ACE began development in 1958 as All-Purpose Ballastable Crawler (ABC). Actual prototyping as the Universal Engineer Tractor (UET) started in 1962 with examples built by Caterpillar Tractor and Universal Harvester, the latter winning the 1963 development award. Operational requirements kept changing, and at times two programs competed for attention.
PACCAR involvement began in 1975;testing of four prototypes ended in August 1976 with type classification to Standard A approved in February 1977. First production did not begin, however, until 1985, as funding was inadequate and the Army demanded further improvements and changes.
Finally, BMYof York, Pennsylvania, began production, with the ACE achieving initial operational capability in 1986. Although the Army originally planned to acquire 1,318 vehicles, ultimately 566 vehicles were to be purchased.
The US Marine Corps announced a requirement for 257 vehicles in 1986; later revisions reduced the number to 180. The first 41 were requested in the FY1993 defense budget.
An undisclosed “Far Eastern” nation ordered ISACEs.
COMBAT EXPERIENCE •
151 ACEs were deployed with US units in Saudi Arabia during Operation Desert Shield. Most were shipped during December and January after being prepared by BMY, including 99 in a 10-day period in January 1991. 30 were “loaned” to the US Marine Corps, 24 of these being used in Operation Desert Storm.
M9s lived up to their job description, preparing US armor and artillery positions and demolishing the barriers raised by Iraqi forces. ACEs were praised as being fast, mobile, and effective. In fact, the 1st Infantry Division’s technique for clearing Iraqi trenches centered on the ACE. The M9 drove down the trench escorted by M2 Bradley APCs on each flank, leaving “a smooth place where the trench had been.” The ACE’s only limitation is that the driver is effectively blind when under armor.
CREW 1 (driver in armored cab)
BALLASTED WEIGHT 54,000 lb (24,494 kg) ground pressure, loaded
14.51b/in (1.02 kg/cm)
hull length 20 ft 6 in (6.25 m) width with dozer wings
10 ft 6 in (3.20m) .over
tracks 8 ft 10 in (2.69
height to top of cupola
9 ft 10 in (2.69 m)
11 in (279mm) with
4,000-lb (1,814-kg) load and armor partially removed ground clearance, sprung
IS’/a in (343 mm) length of track on ground
8 ft 9 in (2.67 m) track width 18 in (460 mm) ARMOR steel, aluminum, and Kevlar armor on engine, powertrain, and operator’s position POWERPLANT Cummins V903C 295-hp liquid-cooled 4-stroke V-8 diesel engine, Clark Model 13.5 HR 3610-2 torque-converter manual transmission with 6 forward/2 reverse gears power-to-weight ratio, ballasted
12.04 hp/metric ton SUSPENSION (EACH SIDE) hydro-pneumatic with rotary actuators, 4 road wheels, rear drive, no front idler or return rollers SPEED road 30 mph (48.3 km/h), water 3 mph (4.8 km/h) with tracks, range 200 mi (322 km) OBSTACLE CLEARANCE vertical 1 ft 6 in
(0.46 m), ballasted gradient 60%, ballasted side 40% slope, trench 5 ft 2 in (1.57 m), fording 3 ft (0.91 m)
The M88 is the principal US medium Armored Recovery Vehicle (ARV) and is based on the M48 Patton Main Battle Tank (MET). It is capable of recovering
and evacuating all US armored vehicles except for some models of the M60 and the Ml Abrams MET. Adoption of the Improved Recovery Vehicle (IRV) with an uprated engine in 1992 was un-enthusiastic, but made necessary by the increasing weight of the Army’s Abrams tank. Two M88Als are needed to tow an Ml tank, a limitation that showed to the MSB’s disadvantage during Operation Desert Storm.
The hull is of cast and rolled armor welded together. The crew compartment is to the front, with the engine and transmission to the rear and doors on either side of the hull.
A blade mounted at the front is used for dozing operations and to stabilize the vehicle when using the winch or crane. The A-frame crane can hoist 12,000 Ib (5,443 kg) with the dozer blade up, up to 40,000 Ib (18,143 kg) with suspension locked out, and 50,000 Ib (22,680 kg) with the blade down. The main winch has
a 90,000-lb (40,824-kg) pull.
A fording kit is available which allows the vehicle to ford water 8 ft 6 in (2.6 m) deep. An auxiliary fuel pump can transfer fuel to other vehicles at a rate of 25 US gal/min (95 liters/mm).
M88 (1,075 delivered from 1961) with
Continental AVSI-1790-6A 980-hp V-12 gasoline engine, M88A1 (2,100 new, 875 converted) with diesel engine, NBC collective protection kit, M88A1E1/M88A2 Improved Recovery Vehicle (IRV) with nearly double crane and winch capacity.
DEVELOPMENT • M88 achieved its initial operational capability in 1961; M88A1 conversions began in 1977. Man-ufacturedby BMYCorp., York, Pennsylvania (later United Defense). Production ended in 1989 but resumed in 1990 after the assembly line layout was reoriented to small-batch orders.
The Army’s dissatisfaction with IRV trials led to the project’s cancellation in April 1989, but lack of options led to de-
velopment funding in September 1992. Production started in 1993 on 186 vehicles planned, with First Unit Equipped
(FUE) planned for FY1994.
In service with the US Army and Marine Corps and over 20 other countries.
COMBAT EXPERIENCE •
US units in Vietnam depended heavily on the M88 for recovery in the field, and the vehicle was widely deployed.
Although it was again widely deployed, the M88′s performance in Operation Desert Storm earned unfavorable reviews. According to Defense News, 3rd Armored Division M88s could not tow M1A1 Abrams tanks and were said to have been “operational” only 60% of the time. The General Accounting Office reported in 1992 that in one brigade of the 24th Infantry Division (Mechanized), Abrams tanks more often towed M88s than the other way around. Moreover, a low towing speed of 5 mph (8 km/h) did not prevent engine and transmission breakdowns.
M88A1: 4 (commander, mechanic,
driver, co-driver) IRV: 3 (commander, mechanic,
M88A1: 112,000 Ib (50,803 kg) IRV: 139,000 Ib (63,049 kg)
M88A1: 10.86 Ib/in*
(0.76 kg/cm*) IRV: 13.40 Ib/in2 (0.94
hull length 27 ft 1 in (8.27 m)
width 11 ft 3 in (3.43m)
height with machine gun
10 ft 3 in (3.12m)
length of track on ground
15 ft 1 in (4.61 m)
17 in (430 mm)
track width 28 in (710 mm)
ARMAMENT 12.7-mm M2 HB machine gun (1,500 rounds)
ARMOR 12.7-50-mm cast armor (IRV
has 30-mm overlay), ballistic armor track skirts on IRV
POWERPLANT Teledyne-Continental AVDS-1790-2DR (M88A1) or -SDR (IRV), 750-hp (M88A1) or 1,050-hp (IRV) air-cooled supercharged fuel-injected V-12 diesel engine, XT-1410^ (M88A1) or -5A (IRV) crossdrive transmission with 3 forward/1 reverse gears power-to-weight ratio
M88A1 14.76 hp/metric ton, IRV 16.65 hp/ metric ton
SUSPENSION (EACH SIDE) torsion bar, 6 road wheels, rear drive, front idler, 3 shock absorbers, 3 return rollers
SPEED 27 mph (43.5 km/h), with towed load on level ground (M88A1) 18 mph (29 km/h) (IRV) 13-25 mph (21-40 km/h), range 280 mi (450 km)
OBSTACLE CLEARANCE vertical 3 ft 6 in (1.07 m), gradient 60%, trench 8 ft 7 in (2.62 m), fording 4 ft 8 in (1.42 m)
M548 Cargo Carrier
The M548 is a full-tracked chassis based on the Ml 13 armored personnel carrier and is used for ammunition resupply and cargo carriage. Although the M548 has proved valuable as an off-road resupply vehicle, it is easily overmatched by high cargo loads. Other M548 modifications carry missile systems and radar stations.
All vehicles in the M548 family have suspensions that differ from the Ml 13 armored personnel carrier only in a thicker torsion bar and different final drive gear ratio. Physically, the M548 differs from the Ml 13 in having a built-up cab and a low cargo deck protected by detachable hollow aluminum panels on the sides and a nylon cover supported by six aluminum bows. An optional cargo beam and traveling hoist can lift up to 1,500 Ib (680 kg).
VARIANTS • M548 (4,970 delivered from 1965) and M548A1 (278 new, 2,806 upgrades) had engine cooling and suspension improvements.
Missile launcher variants include the
M752 (launcher) and M688 (resupply)vehicles for the Lance short-range tactical missile, the M730 Chaparral air defense vehicle. (The M727 HAWK mobile surface-to-air missile system variant is out of service.) Israel’s M548/LAR 160 Multiple Rocket Launcher System carries two 13-round pods or one 18-round pod of 160-mm bombardment rockets.
M1015 communications vehicles carry radio and electronic countermeasures equipment.
Initial operational capability in 1966. In production by FMC Corp., San Jose, California. In service with the US Army and more than 10 other countries.
COMBAT EXPERIENCE •
US units operating in Vietnam found the unarmored M548s vulnerable to mines or artillery, but liked the vehicles’ reliability, crosscountry agility, and relative ease of handling.
20 years later, M548s served most ofthe US artillery units in Operations Desert Shield and Desert Storm. During the buildup, the M548 suffered at first from rubber separating from the road wheels and transmission case cracking. The consensus was that the vehicles had “excellent” cross-country mobility but that the engines tended to overheat.
After the February 1991 ground war, some Army units stressed two points: (1) the M548 performed its mission adequately after adjustments were made to accommodate its limitations, but (2) the Army needs to replace it. The 3rd Battalion, 41st Field Artillery of the 24th Mechanized Infantry Division, encountered “severe maintenance problems” with their 24 fully loaded M548s (96 rounds—
12 pallets—of ammunition). Battalion officers reduced the loads on each of the 24 M548s to seven pallets (56 rounds), which kept all of them running during the 200-mi (370-km) assault.
On the other hand, the 1st Infantry Division’s action report singled out the M548 as “a piece of junk” when asserting the need to replace all but the M113A3. Other units found that maintenance personnel had to put too much effort into keeping the M548s running, which led to a call for more M985 Heavy Expanded Mobility Tactical Trucks (HEMTT).
CREW 4 WEIGHT
combat 28,400 Ib (12,882 kg) payload 12,000 Ib (5,443 kg) ground pressure
8.62 Ib/in* (0.61 kg/cm?)
hull length 18 ft lO’/s in (5.75 m) width, overall
8 ft 10 in (2.69 m) height without machine gun
8 ft 11 in (2.71m), reducible to 6 ft 4 in (2.24m)
17 in (430 mm) length of track on ground
9 ft 3 in (2.82 m) track width 15 in (380 mm)
ARMAMENT fitted with ring mount for 7.62-mm machine gun (660 rounds) or 12.7-mm machine gun (300 rounds)
POWERPLANT CMC Model 6V-53 215-hp liquid-cooled 2-stroke V-6 diesel, Allison TX-100-1 3-speed transmission with torque converter with 6 forward/2 reverse gears power-to-weight ratio
16.69 hp/metric ton
SUSPENSION (EACH SIDE) torsion bar, 5 road wheels, front drive, rear idler, 3 shock absorbers, no return rollers
SPEED 40 mph (64 km/h), acceleration 0-20 mph (0-32 km/h) 14 seconds, range 285 mi (458 km)
OBSTACLE CLEARANCE vertical 2 ft (0.61 m), gradient 60%, side slope 30%, trench 5 ft 6 in (1.68 m), fording 3 ft 3 in (1.0 m) (non-US M548s are amphibious, being propelled in the water by the tracks)
M578 Light Armored Recovery Vehicle
Based on the M107/M110 SPG chassis, the M578 is a light armored recovery vehicle used for recovering disabled vehicles as well as changing major subsystems in the field (engines, transmissions, and guns). It is used primarily for light armored vehicles and other support vehicles.
The hydraulic crane is housed in a turret mounted at the rear of the chassis. A stabilizing spade hydraulically lowers from the rear. Turret traverse is 360°, and the boom’s capacity is 30,000 Ib (13,607
kg). Towing winch capacity is 60,000 Ib (27,030 kg), and the hoist winch can manage 20,500 Ib (9,299 kg). Relatively thin steel armor offers splinter protection.
Designed and built by FMC of San Jose, California, achieving initial operational capability in 1963; 826 delivered by 1969. Bowen-McLaughlin-York (York, Pennsylvania) reopened production in 1971 and built 1,018 more by 1983. In service with the US Army and more than 10 other countries.
COMBAT EXPERIENCE •
M578s were widely deployed in Vietnam during the eight-year-long US involvement. M578s supported US airborne, armored, and infantry units during Operation Desert Storm’s ground war.
COMBAT WEIGHT 53,572 lb (24,300 kg),
air-portable 45,069 lb (20,443 kg)
9.95 lb/in2 (0.70 kg/ cm2)
length hull 18 ft 4 in (5.59 m)
overall 21 ft 1 in (6.43
width 10 ft 4 in (3.15m)
height to top of cupola
9 ft 7 in (2.92 m) length of track on ground
12 ft 4 in (3.76 m) ground clearance
16 in (0.44 m) track width 17 in (0.46 m) ARMAMENT 12.7-mm M2 HB antiaircraft machine gun with 500 rounds
POWERPLANT DetroitDiesel 8V71T
425-hp liquid-cooled turbocharged
V-8 diesel engine, Allison XTG-411-2A
powershift crossdrive transmission with 4 forward/2 reverse gears power-to-weight ratio
17.49 hp/metric ton, loaded
SUSPENSION (EACH SIDE) torsion bar, 5 road wheels, front drive, no idler, no return rollers
SPEED 34 mph (55 km/h), range 450
mi (725 km) OBSTACLE CLEARANCE vertical 3 ft 4 in (1.02 m), gradient 60%, trench 7 ft 9 in (2.36 m), fording 3 ft 6 in (1.07 m)
M728 Combat Engineer Vehicle (CEV)
Based on the M60A1 main battle tank, the M728 CEV recovers disabled vehicles, clears and prepares obstructions, prepares firing positions for artillery, and bombards hostile strongpoints at point-blank range.
The hull is of cast sections welded to-
gether, with the engine, transmission, and fuel tanks in the rear of the hull. A
25,000-lb (11,340-kg) capacity winch is mounted in the bow.
The turret is cast in one piece. The commander and gunner sit to the right of the stubby main, “bunker-busting” M135 165-mm gun; the loader is to the left. This demolition gun fires a 66-lb (30-kg) round to a maximum range of 1,093 yd (1,000 m). In addition to the gun, the turret can support an A-frame crane with 35,000-lb (15,786-kg) capacity.
The Til8 prototype was constructed in 1960; the M728 entered production in 1965. 300 produced at Chrysler Corp.’s Detroit Arsenal Tank Plant, Warren, Michigan, with the M728 achieving initial operational capability in 1968. In addition to US Army service, M728s are found in Saudi Arabian and Singapore army service.
COMBAT EXPERIENCE •
US Army CEVs were used for a variety of tasks during Operations Desert Shield and Desert Storm. During the ground war that began on February 24,1991, they broke through berms and used their Ml 35 demolition gun against obstacles and bunkers. A CEV of the 6th Battalion, 6th Regiment, 1st Armored Division, fired 21 165-mm rounds into the stubbornly defended town of Al Busayyah: “That totally destroyed all the resistance in the town,” according to the battalion commander.
After the cease-fire, CEV guns were used to break up coke piles that had formed around approximately 20% of the burning oil wells in Kuwait. According to the US Army, the guns reduced the time to break up coke formation from as long as two days to 15 minutes.
CREW 4 (commander, gunner, loader, driver)
COMBAT WEIGHT 117,286 lb (53,200 kg)
12.661b/in2 (0.89kg/ cm2)
hull length 29 ft 3 in (8.91 m)
width with blade
12 ft 2 in (3.7 m) height 10 ft 8 in (3.26 m) length of track on ground
13 ft 11 in (4.24m) ground clearance
15 in (381 mm) track width 28 in (711 mm) MAIN GUN 165-mm Ml35 demolition gun with 30 rounds elevation -10°/ + 20°, traverse 360° secondary coaxial
7.62-mm M219 or M240 machine gun and 12.7mm M85 antiaircraft machine gun
hull: 120 mm glacis, 76 mm sides, 44 mm rear, 57 mm top, 13 mm floor turret: 120 mm front, 50 mm rear, 25 mm top POWERPLANT Continental
AVDS-1790-2A or -2D 750-hp air-cooled 4-stroke V-12 diesel engine, Allison CD-850-6A powershift crossdrive transmission with 2 forward/1 reverse ranges
14.38 hp/metric ton
SUSPENSION torsion bar, 6 road wheels,
rear drive, front idler, 3 shock absorbers, 3 return rollers
SPEED 30 mph (48 km/h), range 280 mi (450 km)
OBSTACLE CLEARANCE vertical obstacle 2 ft 6 in (0.76 m), gradient 60%,
trench 8 ft 3 in (2.51 m), fording 4 ft
(1.22 m), with fording kit 8 ft (2.44
M977 Heavy Expanded Mobility Tactical Truck (HEMTT)
The M977 HEMTT (pronounced “hem-met”) is the base vehicle for a series of 10-US ton 8 by 8 trucks that proved versatile, rugged, and reliable during Operations Desert Shield and Desert Storm. The cab seats two and is of heavy-duty, welded-steel construction. The spare wheel is mounted to the right rear of the cab. The cargo area is 17 ft 9 in (5.4 m) long and has drop sides to assist in loading/ unloading.
A light-duty crane (capacity of 47,500 ft lb/6,567 kg m) is mounted on the rear of the truck for loading operations. All variants can be equipped with an optional
20,000-lb (9,072-kg) capacity self-recovery winch. VARIANTS •
M978 2,500-US gal (9,500-liter) tanker, M983 tractor used with M989 Heavy Expanded Mobility Ammunition Trailer (HEMAT), M984A1 wrecker, M985 cargo with crane.
In production by Oshkosh Truck Corp., Oshkosh, Wisconsin, achieving initial operational capability in 1983. The original plan for 7,490 trucks was superseded by purchases that extended procurement to almost 13,000 vehicles.
COMBAT EXPERIENCE •
Few of the US systems used in Operations Desert Shield and Desert Storm received such unconditional praise from their users as did the HEMTT. At the beginning of Operation Desert Storm in January 1991, the US Army had 11,177 HEMTTs in its inventory. 4,410 HEMTTs were deployed in Saudi Arabia, including 1,700 that were described as indispensable to the VII Corps sweep around the Iraqi right during Operation Desert Storm’s ground
war in February 1991. The HEMTTs were the only large cargo vehicles that could keep up with the advance.
A postwar review by officers of the 18th Field Artillery Brigade (Airborne) stated: “This vehicle was an outstanding asset. It could travel through all types of terrain— deep sand, mud, and rocks—with a full load. We loaded HEMTTs to their maximum gross weight capability. They never got stuck and didn’t break down.”
The commander of 1st Armored Division Artillery recommended that “all trucks that operate forward of a division’s rear are either from the HMMWV [High Mobility Multipurpose Wheeled Vehicle]
or HEMTT family of trucks.” Some
HEMTTs were converted to carry the artillery’s Tactical Fire Direction System
The soft sand caused some problems at
first for the HEMTTs of the 27th Field
Artillery of the 42nd Field Artillery Brigade, however. When the support elements jumped off with the 3rd Armored
Division, M985 HEMTTs with M989 HE-
MAT ammunition trailers each carrying four six-rocket MLRS pods struggled to keep pace with the M270 launcher vehicles. Within the first few hours, five drive-shafts had snapped under the strain. A change in driving method to account for the unpredictable traction eliminated the problem.
GROSS VEHICLE WEIGHT RATINGS (GVWR)
62,000 Ib (28,123 kg) except M984A1 95,000 Ib (43,091 kg) and M985
68,000 Ib (30,844 kg)
payload 22,000 Ib (9,979 kg) DIMENSIONS
length 33 ft 4 1A in (10.17 m)
except M983 29 ft 2 Va in (8.9 m) and M984A1
32 ft 9 in (9.98 m)
8 ft (2.44 m) cab height 8 ft 5 in (2.57 m)
distance between equalizer pivots
17 ft 6 in (5.33 m) except M983 15 ft 1 in (4.6 m) andM98415ftllin (4.85 m)
POWERPLANT Detroit Diesel 8V-92TA 445-hp liquid-cooled 2-stroke V-8 diesel, Allison HT740D automatic transmission with torque converter, 4 for ward/1 reverse gears power-to-weight ratio
M977, M978, M983: 16.18
hp/metric ton M984A1: 10.33 hp/metric ton
M985: 14.43 hp/metric ton
SUSPENSION 8 X 8 (8 wheels driving, 4-wheel steering), Hendrickson leaf spring with steel saddle, equalizing beams, and 10-in (254-mm) vertical travel on front and rear
SPEED 55 mph (88 km/h), range with full payload at 33.5 mph (54 km/h) 300 mi (483 km)
OBSTACLE CLEARANCE gradient 60%
M992 Field Artillery Ammunition Support Vehicle
The FAASV (Fas-Vee) is a resupply vehicle based on the chassis of the Ml09 155-mm self-propelled howitzer. A covered superstructure protected by 32 mm of aluminum armor holds ammunition storage racks and a power-operated conveyor belt.
The FAASV carries 93 projectiles, 99 charges, and 104 fuzes in honeycomb storage racks. The on-board Ammunition Handling Equipment (AHE) uses a powered X-Y (Cartesian) stacker to pull rounds from the racks. After assembly and fuzing, the rounds travel to the Ml 09 along a hydraulic conveyor at 6 rounds/ min. An Auxiliary Power Unit (APU) powers the conveyor, stacker, and vehicle electrical system.
The driver of the M992 is located on the left front of the hull with the engine to his right. At the forward part of the superstructure is a three-part resupply hatch behind which is the commander’s cupola. The FAASV has an armored rear door that swings upward and outward to provide overhead protection between the FAASV and the howitzer during loading operations.
FAASVs in service with Egypt are fitted with a 1,500-lb (680-kg) capacity crane at the front of the hull.
Command post vehicle sold to Egypt (72), Greece (41), and Taiwan (six).
M1050 developed to support the MHO 203-mm self-propelled howitzer but not funded.
BMYin York, Pennsylvania, and achieved its initial operational capability in 1985. Original US Army requirement was for one FAASV for each M109 (960 total vehicles), but budget limitations cut procurement to 675. Also in service in Saudi Arabia (60), Egypt (51), and Spain (six).
COMBAT EXPERIENCE •
FAASVs accompanied several US artillery units during Operation Desert Storm. The commander of the XVIII Airborne Corps artillery commented that the one brigade with FAASVs didn’t encounter the mobility problems that affected the others, which were supported by older, slower, unprotected M548 ammunition carriers.
Among the lessons learned was the need for better fire-extinguishing equipment in FAASVs. Although the Halon fire extinguishers operated properly when fire broke out in two vehicles after the ground war, the vehicles were destroyed when the fire reignited and reached the ammunition supply.
CREW 2 (commander and driver) + 6 troops
LOADED WEIGHT 58,500 lb (26,535 kg)
length 22 ft 3 in (6.78 m)
width 10 ft 4 in (3.15 m)
height 10 ft 6 in (3.2 m)
Ml/a in (368 mm)
length of track on ground
13 ft (3.96 m)
track width 15 in (381 mm) ARMOR 32 mm of alloy plate POWERPLANT Detroit Diesel 8V-71T
405-hp liquid-cooled turbocharged
2-stroke V-8 diesel engine, Allison
XTG-411-2A crossdrive transmission
with 4 forward/2 reverse gears
15.49 hp/metric ton SUSPENSION (EACH SIDE) torsion bar, 7
road wheels, front drive, rear idler, no
SPEED road 35 mph (56.3 km/h), up
20% slope 12.5 mph (20 km/h), range 217 mi (350 km) OBSTACLE CLEARANCE vertical 1 ft 9 in (0.53 m), gradient 60%, side slope 40%, trench 6 ft (1.83 m), fording 3 ft 6 in (1.07m)
M998 High-Mobility Multipurpose Wheeled Vehicle (HMMWV)
The US M998 “Humvee” is a 4 X 4-
wheeled tactical vehicle being procured in large numbers to replace several older light trucks and cargo carriers in the US Army, Air Force, and Marine Corps. Like the earlier jeep, the Humvee is reliable, sturdy, capable of operating in all types of terrain, and readily adaptable to a variety of missions. Significant improvements over the Jeep include a better power-to-weight ratio, twice the payload, automatic transmission and power steering, and
HMMWV with Tow
U.S. GOVERNMENT DEPARTMENT OF DEFENSE
better ground clearance. The Humvee is also far less likely to roll over in a sharp turn than was the jeep.
The basic vehicle is a boxy truck using many commercial drivetrain components. Depending on its role, the HM-MWV has a two- or 4-door cab with either a soft canvas top or a hard roof. In its basic configuration, the HMMWV is un-armored and unprotected against NBC warfare. The Humvee is large enough to carry several types of weapons systems, and its speed and cross-country mobility have led to its use as a reconnaissance vehicle.
The common chassis serves as a weapons carrier as well as utility vehicle, ambulance, squad carrier, shelter carrier, TOW antitank guided-missile carrier, and Pedestal-Mounted Stinger (PMS) surface-to-air missile system carrier. A C-130 Hercules cargo aircraft can carry three HMMWVs, a C-141B Starlifter
holds six, and a C-5 Galaxy can transport 15.
Ml046 TOW missile carrier, M996/
M997/M1035 ambulance, M998/M1038 cargo troop carrier, M1025/M1026/ M1043/M1044 armament carrier, M1028
AN/TRQ-32 Teammate Comint system,
M1037/M1042 shelter carrier, M1069 light artillery prime mover, M1097 “Heavy Hummer” with uprated chassis.
After an early 1980s competition, the first AM General Humvee was delivered in 1985. More than 90,000 had been delivered by 1993, with production continuing. Later variants include the M1097 “Heavy Hummer” with an uprated Humvee chassis permitting a Gross Vehicle Weight (GVW) raised to 10,001 Ib (4,356 kg) and
payload increase for shelter carriers to 4,400 Ib (1,996 kg). AM General also tested the Cab-Over Cargo Truck (COCT) with Heavy Hummer chassis adapted to lightweight, high-payload-capacity truck having a GVW of 12,000 Ib
(5,443 kg) and 5,000 Ib (2,268-kg) pay-
Several other national armies and police forces operate Humvees, including Djibouti, Israel, Kuwait, Luxembourg, the Philippines, Saudi Arabia, and the United Arab Emirates. Civilian versions have been sold to the Chinese Ministry of Petroleum and the US Border Patrol, and a $40,000 commercial version became available in 1992.
COMBAT EXPERIENCE •
More than 20,000 Humvees were deployed to Saudi Arabia in 1990 under Operation Desert Shield, where they lived up to their billing as the new jeep. The problems that cropped up were relatively minor, although annoying; these included steering gear box seals leakage, broken generator mounting bolts, and failure of a plastic speedometer gear in the transmission. Flat tires were a problem because the HMMWV doesn’t have a spare wheel and tire as standard equipment.
After Operation Desert Storm began, “up-armored” Humvee scout cars were used by the US Army and Marine Corps to probe Iraqi positions. Many were armed with TOW antitank missiles and 12.7-mm machine guns; their passengers also had laser designators to support coalition air attacks. Marine Combined Antitank (CAT) teams consisted of six Humvees with TOW launchers.
When the ground war began, 50 Humvees of the 101st Airborne Division were airlifted by helicopter to establish a forward base in Iraq. Humvees of all descriptions accompanied the northern rush into Iraq and Kuwait, often taking the surrender of Iraqi units on their own.
CREW 1 (driver) + 3-7 troops or casualties
WEIGHT (lightest and heaviest of M998 series)
curb basic cargo/troop carrier:
5,200 Ib (2,359 kg)
shelter carrier: 5,424 Ib
(2,460 kg) payload basic cargo/troop carrier:
2,500 Ib (1,134 kg) shelter carrier: 3,176 Ib
gross vehicle basic cargo/troop carrier:
7,700 Ib (3,493 kg)
shelter carrier: 8,600 Ib
hull length 15 ft (4.57 m) except ambulance 16 ft 9 in (5.11m), shelter 15 ft 8 in (4.78 m) width 7 ft 1 in (2.16m)
height (depending on role)
5 ft 9 in (1.75m) to 8 ft 8 in (2.64 m) ground clearance
16 in (406 mm) wheelbase 10 ft 10 in (3.3 m) PROTECTION Armament, TOW, and PMS carriers have supplemental armor
POWERPLANT Detroit Diesel 150-hp air-cooled V-8 diesel, automatic transmission with 3 forward/1 reverse gears
SUSPENSION independent double
A-arm with coil spring on all wheels,
front stabilizer bar SPEED 65 mph (105 km/h), range 300
mi (483 km) OBSTACLE CLEARANCE vertical 2 ft 6 in
(0.76 m), gradient 60%, side slope
40%, fording 2 ft 6 in (0.76 m) without preparation, 5 ft (1.52 m) with preparation
M1075 Palletized Load System
The Palletized Load System (PLS) was developed to simplify the handling of bulk resupply from rear areas to near the battlefield. The tractor vehicle is based on the Heavy Expanded Mobility Tactical Transport (HEMTT) and can carry one demountable cargo bed called a flatrack while towing an M1076 or M1077 trailer loaded with a second.
The all-wheel-drive truck has two axles just behind the cab and three more under the bed. The forward two axles and the rearmost axle are steerable, which improves maneuverability. A Central Tire Inflation System can be set to four preset levels—Highway (highest pressure), Cross-Country, Mud-Sand-Snow, and Emergency.
The key to the PLS is the multilift hoist located on the truck bed. Pairs of hydraulic rams extend the upper and lower arms back and down to position the fixed hook under the lift bar mounted on the forward edge of the flat-rack. Once it has hooked the flatrack, the lower arm travels up and forward through a nearly 180° arc, pulling the flatrack onto the truck bed. Up to 24 pallets of ammunition and other heavy cargo can be loaded in one movement. As part of further development, the flat-rack design was upgraded to allow use as an International Standards Organization (ISO) container, which simplifies transportation aboard train, truck, or ship. A 3,900-lb (1,769-kg) lifting capacity crane is also fitted.
Oshkosh Truck Corp. (Oshkosh, Wisconsin) is the builder, the PLS achieving initial operational capability in 1993. Development began in the early 1980s with first test funding requested in 1985; competition
between Oshkosh, GM, and PACCAR.
Originally decided in favor of the PAC-
CAR entry, later retrials resulted in the award to Oshkosh in July 1990. Army goals in 1992 set at 3,400 trucks,
1,521 trailers, and 63,418 flatracks, but
likely to be reduced.
WEIGHT gross vehicle 86,595 Ib (39,290 kg), gross combination 136,970 Ib
truck without flatrack
length: 24 ft (7.34 m) overall width: 8 ft (2.44
height, cab: 9 ft 6 in (2.89
truck/trailer combination length, extended
62 ft 1 in (18.943m)
wheelbase 18 ft 9 in (5.705 m) ground clearance
151/2 in (394 mm) POWERPLANT Detroit Diesel 8V-92TA 500-hp liquid-cooled 2-stroke V-8 diesel, Allison CLT-755 ATEC automatic
transmission with torque converter and 5 forward/1 reverse gears
10X10 (first, second, and fifth axles steer)
front tandem: Hendrickson RT-340
walking beam third axle: Hendrickson Turner air
rear tandem: Hendrickson RT-400 walking beam
SPEED 55 mph (90 km/h), range 336 mi (541 km)
OBSTACLE CLEARANCE angle of approach 42°, angle of departure 62°, turning circle 96 ft (29.3 m), fording
depth 4 ft (1.22m)
Ml078 Family of Medium Tactical Vehicles
The Family of Medium Tactical Vehicles
(FMTV) is a series of 4 X 4 (Light Medium Tactical Vehicle/LMTV) and 6×6
(Medium Tactical Vehicle/MTV) trucks developed to replace aging 21/2-ton (“deuce-and-a-half”) and 5-ton trucks.
To reduce costs and speed up acquisition, bidders were required to use as many commercially available components as possible. The vehicle needed to show good cross-country and adverse-weather mobility, to share at least 75% of its components among variants, to be operated by both large male and small female drivers, and to be easily maintained and repaired.
The basis of Stewart & Stevenson’s winning entry is the Austrian Steyr-Daimler-Puch 12M21 4 X 4 already in service in the Austrian Army. Given the extensive truck-building experience of its two competitors, the choice of Stewart & Stevenson surprised many observers. The size of the program was much larger than any other single effort the company had undertaken before. Stewart & Stevenson officials noted in rebuttal that the company has built many types of specialized vehicles and that the baseline FMTV truck was already in service.
In adapting the 12 M 21, Stewart & Stevenson sharply reduced the foreign content in the design by using US components, including the Allison MD-D7 seven-speed automatic transmission with integral transfer case in place of the nine-speed manual used by Austrian trucks.
The cab is designed to take three passengers. It has power-assist steering, fore and aft adjustable seat, tilt and telescoping steering wheel, and a Central Tire Inflation System (CTIS), which can remotely adjust tire pressure to one of five settings according to road conditions. A 12.7-mm machine-gun mount is fitted to the reinforced cab roof.
Some variants can be delivered to a landing area using the Low-Altitude Parachute Extraction System/Airdrop (LAPES/AD).
LMTV4 X 4 types include the M1078 cargo, M1079 van, M1081
LAPES-capable cargo, and M1080 chassis for other bodies.
FMTV 6X6 types include the M1083 cargo, M1084 cargo with crane, M1085 long-bed cargo, M1086 long-bed cargo with crane, M1087 expansible van, M1088 tractor, M1089 wrecker, M1090 dump truck, M1091 fuel tanker, M1092 chassis, M1093 cargo-LAPES/AD, and M1094 dump-LAPES/AD.
The FMTV program began in 1987 with prototype contracts awarded in October 1988 to BMYTactical Truck Corp. of Marysville, Ohio, Stewart & Stevenson of Sealy, Texas, and Tele-dyne Continental Motors of Muskegon, Michigan. Stewart & Stevenson won the competition in October 1991, with the
First Unit Equipped (FUE) in 1993.
Program goals originally set at 112,000 MTVs procured over a 30-year period. A June 1991 decision scaled the plan down to 89,000 trucks, with first five-year plan reduced from 19,000 to 14,000 and later to 11,000 trucks.
PAYLOAD 4×4, 5,000 Ib (2,268 kg);
6X6, 10,000 Ib (4,536 kg) DIMENSIONS
LMTV: 21 ft 2 in to 21 ft
11 in (6.461-6.682 m) MTV: 22 ft 10 in (6.961 m) (M1093) to 31 ft 9
in (9.689 m) (M1086)
width 8 ft (2.44 m)
height, max to top of cab
9 ft 1 in (2.76 m) wheelbase 4 X 4: 12 ft 9J/2 in (3.9 m) 6×6: ranges from 13 ft 5 in (4.10m) (M1083, M1090, M1093) to 18 ft Vz in (5.5 m) (M1086) ground clearance
22 in (559 mm) ANTIAIRCRAFT ARMAMENT 12.7-mm machine gun mount over cab
POWERPLANT Caterpillar 3116 ATAAC 225-hp (LMTV), 290-hp (MTV) liquid-cooled turbocharged aftercooled inline 6-cylinder diesel engine, Allison MD-D7 automatic transmission with 7 forward/1 reverse gears power-to-weight ratio
18.9-23.7 hp/metric ton
SUSPENSION (EACH SIDE)
front: longitudinal leaf with shock absorbers
rear: longitudinal leaf with shocks (LMTV), bogie with leaf spring over walking beam (MTV)
SPEED 55 mph (88 km/h), range more than 400 mi (644 km) (LMTV), more than 300 mi (483 km) (MTV)
OBSTACLE CLEARANCE approach angle
40°, departure angle 40° (LMTV), 63° (basic MTV), gradient 60%, side slope 30%, fording basic 3 ft (0.91
m), with preparation 5 ft (1.52 m)
Mk 48 Logistic Vehicle System (LVS)
The 8 X 8 Mk 48 LVS is an articulated
cargo transporter that consists of the Mk 48 tractor and four types of Rear Body Units (RBU). Such a design permits much tighter turns (e.g., a turning radius up to 30% less than a conventional fixed-wheel-base truck) and better off-road mobility.
The tractor consists of a two-person cab ahead of the engine and is of heavy-duty, welded-steel construction. The pow-ertrain is identical to that of the M977 Heavy Expanded Mobility Tactical Truck (HEMTT) series.
The tractor and RBU are linked through an articulated joint that transmits power to the rear two axles. The joint is also hydraulically driven to provide 32° of steering (yaw) motion to each side and 6° of roll freedom. The RBUs are quickly interchangeable among the platform, wrecker/recovery, tractor (i.e., fifth wheel), drop-side cargo with crane, and pivoting frame variants.
RBUs include 1,451 Mk 14 logistics platforms for cargo containers, 97 Mk 15 wrecker/recovery with crane and winch, 249 Mk 16 semitractors with standard fifth wheel, 277 Mk 17 cargo bodies with drop-down sides, and 530 Mk 18 tilting-bed platforms converted from Mk 14.
Marine Corps trials began in 1981. Production by Oshkosh Truck Corp., Oshkosh, Wisconsin, ran from July 1985 to September 1989, the LVS achieving initial operational capability in 1986. 1,682 Mk 48 front halves delivered. A total of2,074 RBUs were delivered.
COMBAT EXPERIENCE •
Between 800 and 1,000 Marine Corps LVSs were sent to Saudi Arabia in 1990 for Operations Desert Shield and Desert Storm. All variants except for the Mk 18 were used and performed well.
GROSS VEHICLE COMBINATION WEIGHT RATINGS (GVCWR)
on road Mk 14: 150,000 Ib (68,039
Mk 15 and 17: 153,971 Ib (69,840 kg)
Mk 16: 188,000 Ib (85,275
off road, all versions
105,000 Ib (47,627 kg)
Mk 14, Mk 18: 25,000 Ib
(11,340kg) Mk 17: 20,000 Ib (9,072 kg)
Mkl4, Mk 17: 38 ft
(11.58m) Mk 15: 37 ft (11.28m) Mk 16: 33 ft 1 in (10.09
Mk 18: 35 ft 9 in (10.9 m)
overall width 8ft (2.44 m)
cab height 8 ft 6 in (2.59 m)
distance between axles
1st to 2nd and 3rd to 4th: all models 5 ft (1.52m) 2nd to 3rd: 21 ft 7 in (6.58m) except Mk 16 19 ft 1 in (5.82 m) POWERPLANT Detroit Diesel 8V-92TA 445-hp liquid-cooled 2-stroke V-8 diesel engine, Allison HT740D automatic transmission with torque converter, 4 forward/1 reverse gears
SUSPENSION 8 X 8 (8 wheels driving, front axle and articulated-joint steering) , Hendrickson leaf spring with steel saddle, 6 torque rods and 14-in (356-mm) vertical travel on front and rear
SPEED 52 mph (84 km/h), range 300
mi (483 km) OBSTACLE CLEARANCE gradient 60%, side slope 30%, angle of approach 45°, angle of departure Mk 14 45°, Mk 15 48°, Mk 16 65°, Mk 17 40°