The Komatsu D575A is a crawler tractor of 1,150 horsepower (860 kW) that Komatsu Ltd. built in Osaka, Japan, between 1991 and 2012. Commonly called the world’s largest production bulldozer, it was made in two forms: the SR, or Super Ripper, and the SD, or Super Dozer.
Komatsu D575A at a glance
| Maker | Komatsu Ltd., Osaka, Japan |
|---|---|
| Production | 1991–2012 |
| Configurations | SR Super Ripper and SD Super Dozer |
| Engine | Komatsu SA12V170E, 12-cylinder diesel, 1,150 hp (860 kW) |
| Operating weight | 131,350 kg (SR), 152,600 kg (SD) |
| Blade | 3.63 m high, 7.39 m wide, 69 m³ per pass |
| Optional blade | up to 96 m³ per pass on the D575A-3 SD |
| Length and height | 11.71 m long, 4.88 m tall |
| Ground pressure | 160 kPa |
| Ripper | single shank, digging to 2.06 m |
| Built | 53 machines |
History of the Komatsu D575A
The D555A prototype and the D575A-2
Komatsu first showed a 1,000 horsepower (750 kW) bulldozer prototype, the D555A, at the Conexpo equipment exhibition in Houston, Texas, in 1981. Economic conditions stalled development for much of the 1980s. A successor, the D575A-2 SR Super Ripper, began field testing in North America in 1989 with the Cooney Brothers Coal Company in Pennsylvania, where more than 1,000 hours were logged. Full production started in 1991, and the first production machine was delivered in 1992. It was assembled by Anderson Equipment Company and sold to American Asphalt and Paving Company, which first worked it in Las Vegas. The D575A-2 SD Super Dozer joined it in 1995, the first going to Princess Beverly Coal Co. in Cabin Creek, West Virginia.
D575A-3
The updated D575A-3 and D575A-3 SD were introduced in 2001 and built until 2007. They wore a new trade dress, but most of the changes were electronic: the Palm Command Control System, smooth and soft operation modes, ECMV-controlled transmission and steering clutches and brakes, a preset travel speed selection and an auto-shift down function. The cab received a new suspension seat and upgraded displays and monitoring systems. In 2012 Alcoa in Australia placed a custom order and a final machine was built, bringing the D575A-3 total to 12 and ending production.
Production and use
Between 1991 and 2012 Komatsu built 53 D575A machines. Serial numbers ran from 10001 to 10043 for the A2 series and from 10101 to 10112 for the A3; numbers 10004 and 10013 were skipped because four and thirteen are considered unlucky in Japanese culture. The D575A was used mainly in surface mines in the United States, Australia and Japan, and also in heavy construction and quarries. North American companies bought 31 machines, 14 went to Australia and 8 stayed in Japan. In West Virginia, 17 were in service in the coal fields at one stage, mostly for Alpha Natural Resources and Horizon / Princess Beverly Coal. Alcoa bought five machines for its Western Australian operations and used them, often by remote control, to rip ground that could not be blasted because of nearby housing.
Design and features
- 1,150 horsepower: the SA12V170E is a 12-cylinder, four-stroke, water-cooled, direct-injected, turbocharged and intercooled diesel.
- 69 m³ per pass: the standard Super Dozer blade measures 3.63 m high and 7.39 m wide; an optional blade raised the figure to 96 m³.
- Two layouts: the Super Ripper carried a smaller blade and a large rear ripper, the Super Dozer a very large blade.
- Lock-up converter: the torque converter could be bridged mechanically, passing engine power straight to the transmission.
- Low ground pressure: a track contact area of 9.43 m² kept the average pressure at 160 kPa despite the weight.
Komatsu D575A versions
- D575A-2 SR Super Ripper (1991–2000): 17 machines.
- D575A-2 SD Super Dozer (1995–2000): 24 machines.
- D575A-3 SR (2001–2007): 2 machines.
- D575A-3 SD (2001–2007): 10 machines, plus the custom Alcoa machine of 2012.
The D575A is the largest machine in the Komatsu section, where the other Komatsu dozers, excavators, loaders and trucks are collected.
Sources
- Komatsu D575A, English Wikipedia: development, series, production numbers, specifications, applications
- Komatsu D575A, German Wikipedia: history, engine data, weights and dimensions
- Komatsu D575A, Italian Wikipedia: production period, blade capacity, use
- Komatsu D575A-3, Spanish Wikipedia: development, engine, blade, applications