|Date of first acceptance||1986||Total acceptances||620|
|M9: Manufacturer||BMY Combat Systems||Crew||1 man|
|Height above cupola||118.00"
|Ground pressure, zero penetration||9.5psi
|Welding and bolting|
|Aluminum armor, steel and aramid laminate plates|
|Engine||Cummins V903C; eight cylinder, 4 cycle, vee diesel|
|Transmission||Clark 13.5 HR 3610-2, 6 speeds forward, 2 reverse|
|Steering||Geared steer and clutch-brake|
|Type||Road wheels||Track return rollers|
|Hydropneumatic||4 individually sprung dual/track||Flat track|
|Drive sprockets||Idlers||Shock absorbers||Rear drive||Front road wheels act as idlers||None|
|Single pin, rubber padded steel|
|Ground contact length||105"
|Max level road speed||30mph
|Max water speed||3mph
|Max sideslope with 18,000lbs (8200kg) in bowl||40%|
|Max grade with 18,000lbs (8200kg) in bowl||60%||Max vertical obstacle||18"
|Min turning diameter||Pivot||Max fording depth||36"
|Cruising range||~230mi, roads
The US Army's search for an armored combat earthmover, or universal engineering tractor, spanned thirty years. The resulting M9 ACE features a front-mounted dozer blade behind which is an 8.7 cubic yard (6.7m3) scraper bowl. For jobs requiring a heavier machine, the blade could be raised and the bowl could be filled with dirt, bringing the vehicle's weight up to 57,000lbs (26,000kg). Originally, a 25,000lb (11,000kg) winch was mounted in the lower rear hull, beneath the engine and transmission. This was replaced by a 35,000lb (16,000kg) model with 165' +/- 2' (50.3m +/- .6m) of 3/4" (1.9cm) wire rope. The dozer blade was positioned by adjusting the hydropneumatic suspension. The operator is stationed at the rear of the vehicle and is provided with a cupola containing eight vision blocks. After the vehicle had entered service, modifications were performed that increased the vehicle's weight to the point that swimming was no longer feasible. The amphibious requirement was therefore dropped.