Peterson Twin-631B Tamper compactor with Hyster C400B compacting wheels and two singl-axle Caterpillar 631B scraper tractor, total weight 42 tons, maximum speed 30 km/h.
Engine: Cat D343T 2х370 HP
Oroville Dam Project, Peterson Tractor Co. for Guy F. Atkinson Construction, 1 pieces, Manufactured in the USA in 1966.