In 1974, the largest model Aveling-Barford Centaur 50 with a payload of 50 tons was appeared. The mine truck has classic layoute and equipped with a General Motors V16 2-stroke 18.6 liter 635 hp engine.
The Centaur 50 gradually developed into the RD50 by 1980. It was fitted with a 600 hp Cummins KTA19C engine and Allison 6062. Heaped capacity – 40 yd3. The haulers continue to grow and by the late 1980s, 55-ton RD55 and 65-ton RD65 models were added.
The RD55 was equipped with a 650 hp Cummins KTA19C engine. Heaped capacity – 46 yd3. The RD65 was fitted with a 700 hp Cummins KTA19C engine. Heaped capacity – 50 yd3.