Caterpillar D7

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The Caterpillar D7 Caterpillar track track-type tractor is a medium bulldozer manufactured by Caterpillar Inc.The first D7 appearred in 1938.The D7C came next in 1955.The D7D came in 1959.The 160hp D7E in 1961.The 180hp D7F 1969.The 200hp D7G in 1974.The 215hp in 1986.The D7H was the first D7 to come with the exclusive elevated drive sprocket undercarriage.The D7R replaced the D7H in 1996 with the current D7R Series 2 replacing that.In March of 2008 at Conexpo 2008 held everything 3 years in Las Vegas,Caterpillar introduced the D7E.This 235hp D7E come with a electric drive system and is powered by a 537cid C9 diesel.The C9 powers a generator that turns out electricity that will supply power to a pair of AC drive motors.The D7E's electric drive train has about 60 percent less moving parts then the current D7R Series 2.

USMC D7G
USMC D7G
Two armored D7 bulldozers out on a mission in Ramadi, Iraq.
Two armored D7 bulldozers out on a mission in Ramadi, Iraq.

The D7R Series II at 240hp power and an operating weight of 25 tonnes, is in the middle of Caterpillar's track-type tractors, which range in size from the D3 57 kW (77 hp), 7 t (8 short tons), to the D11 698 kW (935 hp), 112 t (124 short tons).

It is primarily used to move material short distances or through challenging terrain. The vehicle is powerful, yet small and light 16 to 20 t (18 to 23 short tons) depending on configuration). This makes it ideal for working on very steep slopes, in forests, and for backfilling pipelines safely without risking damage to the pipe.

An agricultural version without the blade and rippers is commonly used by farmers.

The US Army used armored D7G to clear mine fields and unarmored D7G and D7H for earthworks. The armored was developed by the Israel Military Industries (IMI). Later, The US Army developed remote-controlled version of the D7G for mine-clearing applications.

The current model is the D7R Series 2 Track-Type Tractor.[1]

[edit] Dozer blades

The dozer blade on front of the tractor usually comes in 4 varieties:

  1. A Straight Blade ("S-Blade") which is short and has no lateral curve, no side wings, and can be used for fine grading.
  1. A Angle Blade: The most common type that it is used on Canada and in Bolivia. Angle Blade is held by an U shape frame that has 3 holes on each side, to set the blade to 3 positions: to the righ center and left.
  1. A Universal Blade ("U-Blade") which is tall and very curved, and has large side wings to carry more material.
  1. A "S-U" combination blade which is shorter, has less curvature, and smaller side wings.

Various other blade types are used including landfill U-Blades, woodchip U-blades, and two-way blades for work inside the holds of ships.

[edit] External links