Abstract: A wide beam, multi-hull icebreaker and method of operation thereof for opening a wide track through which large commercial vessels may traverse is disclosed. The icebreaker includes a plurality of hulls spaced apart and arranged generally in parallel to one another, with each of the hulls including a bow thereon configured to break through a sheet of ice through which the icebreaker traverses. The spaced apart hulls define at least one channel therebetween into which ice broken by the hulls is routed, and the hulls are spaced apart a distance such that a beam of the icebreaker is as wide as a beam of a commercial vessel it is servicing. A conveyor system may be included on the icebreaker that removes broken ice from the channel(s) between the hulls and casts it to the side of the track to leave a less dense track of broken ice.

Abstract: A stump grinding machine for cutting and grinding a stump in the ground includes a mounting frame attachable to a powered vehicle and is a disc mount that is pivotally mounted to the mounting frame. The disc mount rotatably mounts or supports a grinding disc, such that the grinding disc may be pivoted about a generally horizontal pivot axis to move a face of the grinding disc into engagement with the stump to cut and grind the stump. The grinding disc may include a plurality of depth guides for limiting the depth of cut of teeth or blades on the face of the grinding disc. The support frame may be entirely supported at the powered vehicle, such that no support arms or legs or outriggers are positioned at an outer end of the support frame to support the grinding disc above the ground.