Implementations of the accessory and associated methods allow for excavation of a ditch, wherein rotating grating means are used for expelling rubble and form a ditch. The accessory includes grating means which are moved with respect to the ditch to ensure contacting of the grating means with the road and alignment of a rotation axis of the grating means with the ditch axis. The ditch is progressively excavated when the grating means are rotated and displaced along the ditch axis. The grating means may be connectable to a mobile device through an arm assembly configured to controllably move the grating means from the mobile device. The accessory may be used for connection to a mining device for excavating the ditch along the road of an underground mining tunnel.

A watercraft propulsion system for moving a watercraft along a waterway having a bottom and a surface, wherein the watercraft presents a port side and a starboard side. The watercraft propulsion system comprises a boom assembly having a proximal end and a distal end, with the proximal end being rotatably coupled with the watercraft. The watercraft additionally comprises a wheel mounted to the distal end of the boom. The wheel includes at least one generally radially-extending blade assembly, with the blade assembly comprising a primary blade and a secondary blade. The secondary blade extends at an angle with respect to the primary blade so as to present a fluid channel between the primary blade and the secondary blade.

A rotary ditching attachment for an articulated boom of an excavator type machine includes two rotary excavating heads supported in spaced relation on opposite sides of a central support. The heads rotate about a common axis. The rotary ditching attachment is rotatably coupled to the boom by a rotating tool mount. The rotating tool mount is connectable to the central support such that the central support and attached excavating heads are rotatable about an axis extending through the central support and perpendicular to the common axis of the excavator heads. Excavating assemblies are mounted on outwardly facing and inwardly facing surfaces of rotors forming each excavating heads. Rotating the rotary ditching attachment relative to a direction of movement of the rotary ditching tool relative to the ground increases the width of cut of the excavating heads when used to form or rehabilitate a ditch.

A skid steer trimmer assembly usable for contouring the ground including a first housing supporting an auger, a first actuator configured to adjust a first end of the auger and a second actuator configured to adjust a second end of the auger. A stabilizer supporter by a second housing is arranged behind the auger.