Caterpillar D10
The Caterpillar D10 is a track-type tractor manufactured by Caterpillar (then called the Caterpillar Tractor Company) between 1978 and 1986. It was the first tractor in the world to use the elevated drive sprocket to improve durability, operator comfort, and ease of maintenance.
History and features
The Caterpillar D10 was the result of a need for a tractor even larger than the Caterpillar D9. At this time, competitors were building bulldozers that had overtaken the D9 in power. For example, the Fiat-Allis FA-41 track-type tractor had 525 horsepower (391 kW) at the time; the D9 had only around 450 hp (336 kW). The challenges involved in building a machine bigger than all of the rest, especially in the drivetrain, led a group of engineers to build a small machine out of old lawnmower parts. This machine used a high-drive system with a sprung lower roller system. When the test engineers hitched a Jeep onto the little machine, they found that it could pull the Jeep with ease.
Advantages and disadvantages of the High Drive system
The high drive, or elevated sprocket, design also eliminates the final drive system, which tended to break frequently. As the engine and drivetrain are mounted high in a traditional bulldozer, the half-shafts from the differential exit above the drive sprocket, requiring a small gear on the end of the half-shaft and another, larger one attached to the driven sprocket. The high-drive system eliminates the traditional final drive in favor of the planetary final drive, which is more effective at withstanding engine torque, since it spreads the forces over multiple gear teeth instead of a single tooth as in the traditional system. The disadvantage of the system is that it forces the track to move around one more sprocket, reducing track life. Caterpillar claims to have alleviated the problem with the SALT (Sealed and Lubricated Track), which is a permanently lubricated track system.
Introduction of the D10
When the D10 was introduced to the world in 1977, it was the worlds most powerful track-type tractor, with 700 horsepower (522 kW). The then-revolutionary high drive system intrigued spectators who saw the machine at work. The Cat D10 could be ordered with blades up to a 19 foot (5.8 m) U-blade, and weighed in at around 190,000 lb (86,000 kg).
Production and replacements
The Caterpillar D10 was manufactured at Caterpillar's Plant SS in Peoria, Illinois, until 1986. At that time, it was replaced by the 770 hp (574 kW) Caterpillar D11. The D11 carried on the success of the high drive design in the large bulldozers, and the design eventually trickled down to the medium-size bulldozers such as the D6.
Naming scheme
It should be noted that today there is a Caterpillar track-type tractor known as the D10T. This machine is an upgraded version of the D10R track-type tractor, following in the vein of the other T-model releases: D8T and D9T.