Caterpillar D11

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Image:Cat D-11R.jpg
Caterpillar D11 - General Characteristics
Engineering Role:	Heavy bulldozer
Propulsion:	Caterpillar tracks
Engine model:	CAT 3508 (D11R) CAT 3508B (D11R CD)
Gross power:	698 kW (935 hp)
Flywheel power:	634 kW (850 hp)
Operation Weight:	230,100 lb (104,400 kg) (D11R) 248,600 lb (112,750 kg) (D11R CD)
Length:	??? m
Width:	3.802 m (track D11R) 6.706 m (standard blade D11R)
Height:	4.484 m (D11R)
Speed:	11.8 km/h (forward) 14 km/h (reverse)
Blade capacity:	??? m³ (21yd³ to 82yd³)

The Caterpillar D-11 series of tracked-type tractors are among the largest conventional bulldozers in the world, second to Komatsu D575. It comes in two model variations: the standard D11R and the heavier D11R CD.

The D-11 is in the upper end of Caterpillar's track-type tractors, which range in power and size from the D3 with 57 kW (77 hp) of gross power and an operating weight of 8 metric tons, to the D11R CD at 698 kW (935 hp) and 113 metric tons.

D-11s are primarily used for moving large quantities of material (dirt, rock, aggregate, etc.) short distances in relatively confined places. For example, they are often used in quarries. The size, price, power and weight of the larger track-type tractors dictate that they are used primarily for major projects. The D-11 is most commonly found in use in forestry, mining, and quarry operations.

The D-11s are also highly favored for their tremendous power and their ability to rip the earth. They are often used for agricultural and rock ripping. The ripper is the long claw-like device on the back of the tractor. Rippers can come singly (single shank) or in groups of two or more (multi shank rippers). Usually, a single shank is preferred for heavy ripping.

Ripping rock allows the ground surface rock to be broken into small, easy to handle and transport rubble which can then be removed so that grading can take place.

Agricultural ripping allows rocky or very hard earth to be broken up so that otherwise unarable land can be put to use in agricultural applications. For example, much of the very best land in the California wine country consists of old lava flows. Put the D-11 to work and the lava is shattered allowing practical agriculture for the wine industry. In another example, hard earth can be ripped and decompacted to allow the planting of orchards which otherwise could not grow on the land.

The dozer blade on front of the tractor usually comes in 3 varieties:

A Straight Blade ("S-Blade") which is short and has no lateral curve, no side wings, and can be used for fine grading.
A Universal Blade ("U-Blade") which is tall and very curved, and has large side wings to carry more material.
A "S-U" combination blade which is shorter, has less curvature, and smaller side wings.

The nearest direct competitor to the Caterpillar D-11 is the Komatsu D-475. The Cat can be distinguished from the Komatsu by the elevated drive sprocket or "High Drive" system which results in a triangular, rather than oval, shaped caterpillar track.