Hi-Railers at work

I spotted this pair of hi-railers at work on the CN line at Birch Cove this week. A long section of track was being replaced, and these tow rigs were to be found in the midst of a lot of the work.
The International 7600 crew cab is owned by CN and features the usual orange well ventilated, body work.

The Volvo, owned by Holland of Crete Il, carries a flash butt welding device slung from a hydraulic crane mounted inside the body. There is also a large generator in the body to power the welder. The truck can be driven from the ground by controls on the welder unit. Holland specializes in rail track work, see: http://www.holland.co.com/
There are still lots of these first generaiton Volvos with GM cabs on the road (or on the rails in this case).