I was able to locate this bit of information.... http://www.ritchiewiki.com/wiki/index.php/Euclid_Road_Machinery_Co.
Twin Engine Concept
Building on the prosperity of its off-highway trucks and bottom-dumps, Euclid expanded after the war and built one new plant and purchased a second in the vicinity of Euclid. In 1949 Euclid developed the first wheel tractor-scraper that had two engines, one powering the scraper and a separate engine powering the scraper’s wheels. Such a development was only achievable in part to the 1948 introduction of the Allison Division of GM’s first semi-automatic “Torqmatic” transmission that had a torque-converter drive. With the Torqmatic transmission mounted to two engines, the tractor and scraper driving wheels operated in sync. In 1949 the two-engine concept was applied to off-highway trucks.