Today in WW II: 14 Jan 1943 Churchill and Roosevelt begin the Casablanca conference.   

Mack NJU-1 Ponton Tractor, 5-ton, 4x4 (G-639)

The Mack NJU-1 Ponton Tractor, 5-ton, 4x4 (G-639) was a specialized tractor for towing ponton trailers loaded with bridge sections. The Mack NJU-1 was powered by the Mack EN532 6 cyl., 136hp engine, with 532 cu. in. displacement. The wheelbase was 148 inches, width 96 in., length 237 in. and height 114 in. The maximum lowed load was 30,000 lbs. The box behind the cab was for stowage of tools and equipment related to bridge erection duties.

See also the very similar Autocar U-8144-T Ponton Tractor.

Mack NJU-1 Ponton Tractor, 5-ton, 4x4 (G-639)
Mack NJU-1 Ponton Tractor, 5-ton, 4x4 (G-639).

1941 photo of Mack NJU-1 Ponton Tractor, 5-ton, 4x4 (G-639)
1941 photo of Mack NJU-1 Ponton Tractor, 5-ton, 4x4 (G-639).

Mack NJU-1 Ponton Tractor, 5-ton, 4x4 (G-639) with ponton trailer
Mack NJU-1 Ponton Tractor, 5-ton, 4x4 (G-639) with ponton trailer.