Caterpillar is celebrating the production of 175,000 of its medium dozers since their launch 35 years ago. Travel restrictions mean that Cat is unable to gather customers and dealers together for in-person celebration, but has produced three special commemorative tractors and produced the short video, below.
In 1985, Caterpillar expanded its elevated sprocket undercarriage concept to its medium track-type tractor (MTTT) line with the launch of the H-Series models. Still unique to this day for the 130 to 350 hp (100 to 250 kW) dozer class, the high drive design conformed to the ground better, improving durability, serviceability and performance compared to low-drive and oval track designs, Cat says
The D4H, D5H, D6H and D7H dozer models were the first to feature the high drive design, and in 1987 the D8L model was added to the family.
In addition to bringing many of the same large dozer advantages to the medium line, the elevated drive sprocket allowed movement of the front and rear track idlers. This helped to fine-tune machine balance and ground pressure for specific applications more easily than oval track machines. For the first time, variable pitch angle tilt (VPAT) blades were made available to high drive dozers with the D4H and D5H models for finishing jobs faster by grading at higher speeds.
Caterpillar celebrated the elevated sprocket design in the medium dozer class by producing three commemorative 175,000 units in May 2020. The first two were D6 XE electric drive dozers, with a dark gray and black paint scheme. The third was a D6 dozer with 4-speed, fully automatic transmission, finished in traditional Cat yellow with black tracks and blade. There are special decals on the outside, while the seat headrests in the cabs are embroidered with the '175,000' logo.
Long-time Caterpillar customer Goodfellow Bros., a family-owned contractor based in Washington state, received one of the D6 XE units. Texas dealer Holt Cat, took the second and plans to use it to help promote Cat dozers at future customer events.
The yellow commemorative D6 dozer was shipped to Finning in Canada, where it was sold to Midwest Pipelines.