Olive-Drab.com Military HQ
What's New? | Olive-Drab Directory | Adv Search  
  Home >> Military Vehicles >> Charts >> Earthmovers >> WW II Bulldozers >> D4 Cat

Vehicles Weapons History Uniforms/Gear Rations War Dogs Photos/Video Info/Intel FAQ Store Facebook/Blogs

Loading...
Military Theme
T-Shirts & Stuff
Visit Olive-Drab.com's sister site for
over 8,000 free military vehicle photos!

D-4 Caterpillar Bulldozer

The diesel powered Caterpillar D4 evolved from the Cat R4 gasoline tractor. In 1936, the Cat R4 was joined by the diesel RD4 (4G series) and in 1937 the RD4, with some minor modifications, was renamed the D4 (4G series).

The early D4 models (4G, 7J, 2T, 5T) were powered by the Cat D4400 engine developing 35 drawbar horsepower. A small gasoline pony motor was used to start the diesel. The 6U and 7U were upgraded to the Cat D315 4 cyl diesel with 43 drawbar hp.

Caterpillar D4 tractor mired in deep mud during Alcan Highway construction, Alaska, 1942
Caterpillar D4 tractor mired in deep mud during Alcan Highway construction, Alaska, 1942.

Today in WW II: 31 Jul 1941 SS Major General Reinhard Heydrich ordered by Göring to prepare "...a total solution of the Jewish question [Gesamtlösung der Judenfrage]..." in European areas controlled by Germany.   

D-4 Caterpillar Bulldozer

During WW II, the D4 was one of the tractor/bulldozers collectively known as "Tractor, Light." The Caterpillar D4 models were Ordnance G-151. Equivalent tractors were produced during WW II by International Harvester Co. (Model TD9, G-99). The Cat D4 was used as a prime mover for light artillery, for general duty as a tractor, or as a bulldozer when equipped with a suitable blade attachment.

The evolution of the D4 included these models:

  • D4 4G series 1937-1938, Orchard model
  • D4 7J series 1939-1942
  • D4 2T series 1943-1945
  • D4 5T series 1945-1947
  • D4 6U series 1947-1959, 44 inch gauge
  • D4 7U series 1947-1959, 60 inch gauge

Over 7,400 of the 5T series were built and over 44,000 7U units were produced. Tractor serial numbers were composed of the series (eg 4G, 6J) followed by a four or five digit serial number. With modifications and additional series, the D4 continued in production and remains in the Caterpillar product line in the mid-2000s.

Thanks to Stephen A. Sarkany for help with this page.

Caterpillar D4 tractor in use during Alcan Highway construction, 1942
Caterpillar D4 tractor in use during Alcan Highway construction, 1942.

Caterpillar D4 tractor in use on Attu Island, Aleutians, May 1943
Caterpillar D4 tractor in use on Attu Island, Aleutians, May 1943.

Caterpillar D4 tractor configured as a bulldozer belonging to U.S. Fifth Army, on raft in Volturno River, Italy, October 1943
Caterpillar D4 tractor configured as a bulldozer belonging to U.S. Fifth Army, on raft in Volturno River, Italy, October 1943.

Find at Amazon:  Military Issue equipment, clothing, boots, MREs, MOLLE gear and much more.

  Home >> Military Vehicles >> Charts >> Earthmovers >> WW II Bulldozers >> D4 Cat What's New? | Olive-Drab Directory | Adv Search