M1 Light Tractor
Prior to and during the Second World War the United States Army called several tractors M1 Light Tractor. Under the Ordnance Corps these "off the shelf" tractors were meant to tow artillery pieces so were not equipped with blades like their Engineer counterparts. Eventually these were replaced by purpose built "High Speed Tractors" (HST). Some tractors were equipped with crane attachments for ammunition, and material handling. Detailed information on Caterpillar D4. TB 5-9720-11 (1944) gives the following detailed information: TRACTOR, CRAWLER, DIESEL, 35 TO 40-DBHP, STANDARD, CATERPILLAR, D4 Mfr: Caterpillar Tractor Co. Stock No .: 78-8138.0-44 Peoria, 111. Model: D4 1. General. — The D4 is designed for towing and all types of general construction work. Accurately located frame-holes are provided for attaching varied tractor equipment to adapt it for use in earth moving, road clearance, and airport construction work. 2. References. — For further information regarding this equipment, refer to: TM 5-3110; ASF Catalog, Section ENG 7-T31, ENG 8-T31. 3. Engine. — Make: Caterpillar. Model: D4. Fuel: Diesel commercial. Cylinders: 4. Bore and Stroke: 4}£ x 5K-in. Governed speed: 1400 rpm. Valve adjustment: 0.010-in. Firing order: 1-3-4 -2. Equipped with Independent, 2-cylinder, 4-stroke-cycle gasoline starting engine. 4. Fuel, coolant, and lubrication data. — Fuel tank: 25-gal fuel oil. Radiator: 11 -gal water. Crankcase: 4-gal engine oil. Transmission: 5-gal gear oil. Final drive cases: 1%-gal gear oil each. Engine oil grade: OE-30 above 32 F, OE-10 below 32 °F. Gear oil grade: GO-90 above 32 F, GO-80 below 32 °F. 5. Speeds and drawbar pull. — Five forward speeds and one reverse. Reverse speed: 1.9 mph. Forward speeds with maximum drawbar pull are: 1st: 1.7 mph, 7852 lb. 2nd: 2.4 mph, 5811  lb. 3rd: 3.0 mph, 4541 lb. 4th: 3.7 mph, 3471 lb. 5th: 5.4-mph, 2230-lb. 6. Clutch. — Power is transmitted through dry type flywheel clutch to selective type change speed gear set. Each track is controlled by slow speed, heavy duty, dry multiple disc clutch. 7. Brakes. — Contracting band brakes. 8. Crawlers. — Gage, center to center of tracks: 44-in. Track length: 61%-in. Track shoe width: 13-in. Grouser height: 2 in. Track shoes, each side: 31. Ground contact: 1589 sq in. 9. Attachments. — The following attachments are issued as standard equipment with the D4 Caterpillar: ANGLEDOZER, LaPlante-Choate  4R. ANGLEDOZER, LeTourneau C-4. BULL- DOZER, LaPlante-Choate or LeTourneau A-4. POWER CONTROL UNIT, LeTourneau T-4. COMBINATION POWER CONTROL UNIT AND WINCH, LeTourneau, HN. WINCH, Hyster D-4A. WINCH, Hyster D4. 10. Dimensions. — Length: 121% 6 in. Width: 62 in. Height: 60% in. Drawbar height: 13%-in. Turning radius: 74-in. 11. Working weight. — Without attachments: 10,000-lb. 12. Shipping data. — Boxed for export (tractor only), completely assembled. No. of boxes: 1. Length: 126-in. Width: 68-in. Height: 69-in. Cubage: 343 cu ft. Weight: 11,600-lb. Military service. An iconic vehicle used by the Seabees during [WW2] Seabee. Often seen  with the term "Natasha", the name of the bulldozer in the John Wayne movie "The Fighting Seabees"The Fighting Seabees. It was equipped with a plow and shipped off to islands in the pacific to help build a variety of items, including Airstrips, Supply Depots, and Roads.