Forty years ago this September, Caterpillar rolled off of its production lines 10 pilot models of D10 dozer, representing a radically different design, high weight and horsepower and resilient undercarriage that answered the growing calls from large mining and big heavy construction operations for a more powerful dozer.
“We bucked conventional wisdom with the D10 and tinkered with a centerpiece that was a part of the Caterpillar product line since the company was formed in 1925,” says George Alexander, a retired Caterpillar engineer who served on the D10 research team and one of four individuals named on the patent for Caterpillar’s elevated sprocket design.
The result of the team’s out-of-the-box thinking was a machine offering 50% higher productivity than Caterpillar’s largest dozer of that era, the D9. The new D10 weighed over 190,000 lbs. and measured 15 ft. tall, 12 ft. wide and slightly more than 31 ft. long. Power was supplied by the 700-hp D348, V12 diesel engine.
The pilot D10 dozers built in 1977 were immediately embraced by Caterpillar customers. Their ripping and pushing capabilities made a significant impact on the mining industry, as studies showed the cost/yard to move material using the D10 was comparable to that of larger draglines. The undercarriage with elevated sprocket conformed to the ground better than solid tracks, helping to improve machine pushing power and undercarriage life and enhancing operator comfort.
The dozer’s modular concept helped to increase machine transportability, as removable components facilitated machine moves from location to location. Its modular design also substantially advanced assembly and service task efficiency. The transmission and bevel gear removal and installation times on the D10 compared to that of the D9H dropped to 6 hours from 30 hours, while service time on the final drive plummeted to 9 hours from 45 hours, lowering long-term operating costs.
The original Cat D10 legacy lives on today with thousands of Caterpillar elevated sprocket dozers operating around the world. The elevated sprocket track concept has been expanded to today’s Cat D6N and D6T medium dozers and the D8T, D9T and D11T large dozer models as well as the current D10T2 model.
“After I retired in the 1990s, I gave my presentation on the development of the elevated sprocket design, and a person afterwards said to me, ‘Wherever you go, you will see the results of your work,’” recalls Alexander. “He was right. No matter where I traveled in the world, I saw dozers with the elevated sprocket design, and it made me proud to be a part of the original research team.”
