Vet ikke, men "tram crane" er "løpekran". Vitsen er at dett er en flyttbar rigg (mobile, steerable drilling rig.. The mast is oriented horizontally when tramming, i.e., when driving the rig from one site to another. On the other hand, the mast is oriented vertically during a drilling operation.)

--------------------------------------------------
Note added at 9 hrs (2008-03-21 22:56:44 GMT)
--------------------------------------------------

Tror nok det kan passe med kjøre(s) eller forflyttes. Bruker belter eller kanskje noen ganger skinner.
The embodiment is directed toward a self-contained underground drill rig 10 comprising a drilling machine 11, a water-cooled diesel engine 12, a cooling unit 14, and an operator's compartment 16 all mounted upon a chassis 17. The drill rig 10 is provided with an endless belt tramming system 18 driven by tram motors, for locomotion of the drill rig 10.

http://www.wipo.int/pctdb/en/wo.jsp?wo=1999002814&IA=WO19990...

The Sunrise operators also comment favourably on the rig’s tramming ability, which enables them to move the rigs quickly and safely around the site.
http://www.ferret.com.au/n/Sun-rises-on-new-breed-DTH-crawle...

The remote tramming system allows the rig to move without an operator onboard.
www.prosoniccorp.com/pdf/SonicTimes_Vol3_Issue2.pdf