20130312733 | Ground Excavation Preparation System - A ground excavation preparation apparatus for thawing a frozen ground surface prior to excavation, consisting of a trailer; a housing connected to the trailer; mobility means attached to the trailer for moving the apparatus; heat generation means above the housing for supplying thawing energy; heat distribution means within the housing for transferring heat into the ambient air within the housing; and hydraulic means connecting the trailer to the housing for raising and lowering the housing at an excavation site. | 11-28-2013 |