The International Harvester TD-20 Tractor / Bulldozer was the successor to the IH TD-18 used during World War II. The IH TD-20 was introduced in 1958, replacing the last upgraded model of the TD-18. The TD-20 was produced in several models including the TD-20B, TD-20C, TD-20E, and TD-20H. In addition to International Harvester, the TD-20 has been produced by Dresser, HSW, and Dressta as they successively took over the original IH line of tracked vehicles starting in 1982. The TD-20H continues to be marketed by Dressta in the mid 2000s.
The IH TD-20 tractor is powered by a 691 cid 6 cyl diesel engine producing 110 drawbar hp, mated to a 6 speed transmission.
The military nomenclature for the IH TD-20 is Tractor, Full Tracked, Low Speed, NSN 2410-00-928-7491.
International Harvester TD-20 Bulldozer photographed during construction at Phu Cat Air Base, Vietnam. April 1967, operated by member of the 819th RED HORSE Squadron, USAF. Thanks to Ron Nash for correct ID.