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Cat high-drive medium dozer milestone

Cat D6 XE dozer

Caterpillar celebrate production of 175,000 medium high-drive dozers with three commemorative units

IN 1985, Caterpillar expanded their revolutionary elevated sprocket undercarriage concept to their medium track-type tractor (MTTT) line with the launch of the H-Series models. Still unique to this day for the 130–350hp (100–250kW) dozer class, the high-drive design conformed to the ground better, improving durability, serviceability and performance compared with low-drive and oval track designs.

The Cat 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 the D4H and D5H high-drive dozers models.

Thirty-five years later, Caterpillar celebrated the unrivalled success of the elevated-sprocket design in the medium-dozer class by producing three commemorative 175,000 units in May 2020.

‘One of the original taglines to promote the early high-drive tractors was ‘Beyond Known Capabilities’, because these units set a new standard for efficiency, productivity and ease of operation,’ said Wes Holm, chief engineer for Caterpillar medium tractor products.

‘With our next-generation medium dozer line, which includes the new D5, D6 and D7 models, we continue to push these envelopes through adaptation of technology to drive productivity and efficiency to another level.’

Three customers have now taken possession of the commemorative units, which feature special decals on the fenders denoting the 175,000-unit milestone. The 175,000 image appears inside the cab too, where it is embroidered on the headrest and printed on a plaque denoting each unit’s limited-edition status.

Built in East Peoria, Illinois, the first two commemorative units were Cat D6 XE electric drive dozers, featuring a dark grey and black paint scheme. The third unit, a D6 dozer with four-speed, fully automatic transmission, is finished in traditional Cat yellow with special black tracks and blade.

Symbolic of the medium dozer line’s long history of innovation, the Cat D6 XE is the world’s first electric drive dozer to offer the elevated sprocket design. Delivering up to 35% improved fuel efficiency, the dozer also offers long service intervals and extended scheduled maintenance to reduce service and maintenance costs by up to 12%.


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