||26.5 ft (8.1 m)
||14.7 ft (4.5 m) (blade)
||13 ft (4.0 m)
||108,000 lb (48,988 kg)
- CAT C18 ACERT (D9T)
- 3408 HEUI (D9R)
- 464 hp (346 kW) D9T
- 474 hp (353 kW) D9R
- 410 hp (310 kW) D9T
- 410 hp (310 kW) D9R
- 375 hp (280 kW) D9N
- 460 hp (340 kW) D9L
- 7.3 mph (11.7 km/h) Forward
- 9.1 mph (14.6 km/h) Reverse
- 17.7 cu yd (13.5 m3) 9 SU blade
- 21.4 cu yd (16.4 m3) 9 U blade
CAT D9L, the first D9 model to employ the "high drive" configuration.
The Caterpillar D9 is a large track-type tractor designed and manufactured by Caterpillar Inc. 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 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. The Komatsu D275A is one of its most direct competitors.
Engineering and technical description
The D9 is a series of heavy tracked-type tractors, propelled by Caterpillar tracks and usually used as bulldozers. The series began in 1954 with a prototype tractor called the D9X. Ten D9X prototype models were built in 1954. In 1955, the 286 hp (213 kW) D9 was introduced to compete against the more powerful Euclid TC-12. The D9 came equipped with a 1,473 cidD353 which powered the D9 right up until the 1980 introduction of the D9L. In 1956 the D9 had its engine power raised to 320 hp (240 kW). The new 335 hp (250 kW) D9E replaced that model in 1959. Two years later, in 1961, the legendary 385 hp (287 kW) D9G was introduced, that remained in production for 13 years. Over its 13-year life the D9G became the main crawler on many job sites, testifying to its sturdiness and design.
In 1965, West Coast businessman Buster Peterson hooked up a pair of D9Gs to pushload the largest wheel tractor scrapers built. In 1986 Caterpillar bought the rights to this concept and thus the 770 hp (570 kW) DD9G was created (D stands for Dual D9G). Peterson also built the first SxS D9G which has two D9Gs side-by-side, pushing a 24-foot (7.3 m) wide bulldozer blade.
In 1969, Caterpillar introduced this new SxS D9G. In 1974, the improved 410 hp (310 kW) D9H was introduced to replace the D9G. The D9H is still the more powerful conventional track-type tractor in company history. The DD9H and the SxsD9H would soon follow.
In 1980, the 460 hp (340 kW) D9L was introduced. The unit featured the same new type of elevated-sprocket undercarriage as was used in the larger D10. The D9L was the first variation of the D9 to employ elevated-drive-sprocket design in which the drive sprocket is elevated above the track, and not on the ground. The new undercarriage design reduced strain and shock loads on the final drives and gave the "belly pan" more ground clearance. The elevated-drive-sprocket undercarriage is a modular design. To repair the machines one breaks down the tracks and pulls the drive sprockets out. As a result, one can pull the powershift transmission out the rear. The 370 hp (280 kW) D9N replaced the D8L in 1987.
In 1988, Caterpillar produced their 25,000th elevated-drive-sprocket track-type tractor, a D9N. The 405 hp (302 kW) D9R replaced the D9N in 1996. The 410 hp (310 kW) D9T replaced the D9R in 2004. The D9T has a low-emissions ACERT diesel engine. The current model is the D9T; however, older models such as the D9R, D9N, and D9L are still commonly used. The L, N, R and T models of the D9 are visually very similar, differing primarily in the design of their internal systems.