Autocar (USA) started by building motorised tricycles and cars from 1897, turning to general trucks from 1907 and later to special purpose heavy-duty trucks. Autocar was bought by White in 1953.
An Autocar 6x6 truck fitted with a drilling rig at the Historic Commercial Vehicles Show. The transfer case has a power take-off (PTO) capability but the drilling rig, probably of later vintage than the truck, is self-powered. The all wheel drive truck would be needed for access to difficult work sites.
See the 4WD Vehicles page