Caterpillar D8

The Caterpillar D8 is a medium track-type tractor designed and manufactured by Caterpillar. Though it comes in many configurations, it is usually sold as a bulldozer equipped with a detachable large blade and a rear ripper attachment.

History

 * 1935: RD8 (132 hp) introduced.
 * 1937: The "R" prefix dropped, D8 debuts.
 * 1940s: D8 2U Series (148 hp) introduced
 * 1950: D8 new front-rounded grill that would last until D8K was replaced by D8L in 1982.
 * 1955: 1H Series D8 ends production; 191 hp D8E and D8D introduced with new 1,246 cuin displacement (CID) D342 diesel engine. D8D had a torque converter and D8E had a direct drive transmission.
 * 1956: D8D replaced by D8G.
 * 1956: D8E replaced by D8F.
 * 1958: 235 hp D8H introduced.
 * 1965: Power increased to 270 hp
 * 1970: D8 46a 48a power increased 280 hp
 * 1974: 300 hp D8K replaced the D8H.
 * 1982: 335 hp D8L replaced D8K. The D8L was the first D8 with the elevated drive sprocket undercarriage.
 * 1984: D8L SA (special application) for farming applications premiers. Available with a three point hitch, for mounted implements.
 * 1987: D8N (285 hp) with differential steer transmission, the first track-type Caterpillar tractor to have one.
 * 1996: 305 hp D8R replaced D8N.
 * 2000: D8R Series 2 replaced the D8R.
 * 2004: 310 hp D8T ACERT replaced D8R Series 2.

Blades
Several types of bulldozer blade can be used on the front of the tractor:
 * Straight ("S-Blade"): A short blade with no lateral curve and no side wings. It can be used for fine grading
 * Angle: held by a U shape frame that has three holes on each side, to set the blade to 3 positions: right, center, and left.
 * Universal ("U-Blade"): A tall and very curved blade with large side wings to carry more material
 * "S-U" combination: A shorter blade with less curvature and smaller side wings

Other blade types include landfill U-Blades, woodchip U-blades, and two-way blades for work inside the holds of ships.