|Caterpillar D9 - General Characteristics|
|Engineering Role:||Heavy bulldozer|
|Engine model:||CAT C18 ACERT
3408 HEUI (D9R)
|Gross power:|| 464 hp (346 kW) D9T |
474 hp (354 kW) D9R
|Flywheel power:||410 hp (306 kW) D9T|
410 hp (306 kW) D9R
375 hp (280 kW) D9N
460 hp (343 kW) D9L
|Drawbar pull:||71.6 tons|
|Operation Weight:||107,550 lbs (48,784 kg)||Length:||26.5 ft (8.1 m)|
|Width:||14.7 ft (4.5 m) (blade)|
|Height:||13 ft (4 m)|
|Speed:||7.3 MPH (11.9 km/h) Forward|
9.1 MPH (14.7 km/h) Reverse
|Blade capacity:||17.7 yd³ (13.5 m³) 9 SU blade|
21.4 yd³ (16.4 m³) 9 U blade
Though it comes in many configurations it is usually sold as a bulldozer equipped with a detachable large blade and a rear ripper attachment.
The D9, with 354 kW (474 hp) of gross power and an operating weight of 49 tons, is in the upper end, but not the heaviest, of Caterpillar's track-type tractors, which range in size from the D3 57 kW (77 hp), 8 tons, to the D11 698 kW (935 hp), 104 tons. The size, durability, reliability, and low operating costs have made the D9 one of the most popular large track-type tractors in the world, with the Komatsu D275A as one of its most direct competitors.
The D9's primary working tools are the blade, affixed to the front and controlled by 6 hydraulic arms, and the optional ripper, which can be attached to the back. The blade is mainly intended for earthmoving and bulk material handling: pushing up sand, dirt and rubble. It also can be used to push other heavy equipment such as earthmoving scraper pans, and in military applications, main battle tanks. The dozer blade usually comes in 3 varieties:
The rear ripper is intended for use in loosening rocky ground and ripping out larger stones. It can also break frozen ground and excavate small ditches. The ripper can be replaced with a multi-shank ripper, allowing the bulldozer to comb the ground.
The size, power and weight of the larger track-type tractors dictate that they are used primarily for major projects. The D9 is most commonly found in use in construction, forestry, mining, waste, and quarry operations.
Caterpillar Inc. does not manufacture a military version of the D9 per se, but the attributes that make the D9 popular for major construction projects make it desirable for military applications as well, and in this role - with Israeli modifications and armor - it has been particularly effective for the Israel Defense Forces (IDF) and later for the United States armed forces (the Marine Corps and the US Army) in Iraq.
The Israeli Engineering Corps used armored versions of the D9L, D9N and D9R to clear booby-trapped areas, open routes, rescue stuck armored fighting vehicles and build sand mounds. During the Al Aqsa Intifada D9 bulldozers were used to demolish alleged terrorists' houses under fire, as the dozers withstood massive IEDs (some of 200 kg and even 500 kg of explosives) and even deflected RPG rounds and were impervious to machinegun fire. The armored D9 bulldozers were cited by experts as one of the key factors for the relatively low casualties of the IDF in urban warfare. However, while Israel saw the utilization of bulldozers as a security necessity, it drew controversy for the destruction it caused to Palestinian property, especially in Rafah and in Jenin (during Operation Defensive Shield).
On February 7, 2006, the Synod of the Church of England decided to divest itself of approximately USD$2.2 million in Caterpillar Inc. shares, property of the Church of England. This was seen as a move to distance itself from the Israeli army's documented use of the Caterpillar bulldozers to destroy Palestinian homes. The family of Rachel Corrie filed a law suit against the IDF and Caterpillar, but it was rejected by the US court.
The US army used D9 bulldozers to clear forest in the Vietnam war but after the war they were replaced with smaller and cheaper Caterpillar D7G bulldozers. D7G dozers are still very common in US combat engineering battalions, but there is a resurgent high demand to replace the lighter D7Gs with the newer and more heavily armored D9s.