Caterpillar DD9G '1969–74
Buster Peterson combined two Cat D9Gs end-to-end to create a single pushloading tractor with twice the power, but for high-volume material handling with a crawler tractor, the issue wasn't so much the horsepower as it was blade capacity. Various experiments were attempted – and failed – in creating a more powerful, higher-capacity dozer by combining two large crawler tractors onto one undercarriage.
Caterpillar DD9G '1969–74
Buster Peterson combined two Cat D9Gs end-to-end to create a single pushloading tractor with twice the power, but for high-volume material handling with a crawler tractor, the issue wasn't so much the horsepower as it was blade capacity. Various experiments were attempted – and failed – in creating a more powerful, higher-capacity dozer by combining two large crawler tractors onto one undercarriage.
WheelsAge.org '2005–pr.