Of all articles I have written on glider cargo, the Case CA-1 Crawler tractor, commonly referred to as a bulldozer, probably has the least amount of information available on it. Researching this article was quite a challenge until I came upon an excellent article and website, both of which had some serious work behind them. I want to give their authors Steve Hanson and David D. Jackson full credit for this information which makes up much of the CA-1 information presented here. https://usautoindustryworldwartwo.com/clarkequipmentcompany.htm and Mules, Beetles and Flying Bulldozer.
Prior to World War II engineering and construction equipment was transported by ship, roads, or rail. Thanks to the foresight of General Hap Arnold and Brigadier General Stuart Godfrey the airborne engineering unit was proposed and developed in June of 1940. This would allow an Aerial Engineering Unit transported by Troop Carrier C-47's and gliders to repair and defend landing strips wherever needed. If the traditional modes of transport prior to 1940 had continued to be the sole method of moving heavy equipment, it would have made the runway making capabilities in the jungles of the Pacific all but impossible. With the extensive damage from the bombing of railroads and railheads, roads and in the European Theater of Operations the Airborne Engineering Unit and its ability to utilize aerial transport more than proved its worth.