Today in WW II: 21 Nov 1942 ALCAN Highway opened for its first full day of traffic.  More 
21 Nov 1943 Hitler appoints Luftwaffe Field Marshal Albert Kesselring as commander of all German forces in Italy.
Visit the Olive-Drab.com World War II Timeline for day-by-day events 1939-1945! See also WW2 Books.

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.