Abstract: A guided transport unit and methods of guiding the transport unit for moving a superstructure in precise angular movements over a surface are disclosed. The guided transport unit comprises a skid pad, a vertical displacing member engaged with the skid pad, a base operatively associated with the vertical displacing member, and a directional actuator. The base includes a planar element for engaging the surface over which the superstructure is transported, and a carrier for moving the vertical displacing member and skid pad relative to the surface. The directional actuator controls and secures the relationship among the vertical displacing member, the base, and the skid pad for positioning the base in a predetermined direction to engage the surface, setting the carrier to move each skid pad in a predetermined direction across the planar element of the base, and repositioning the base in another direction for movement of the guided transport unit.

Abstract: Deformed pipes used for lining host pipes are provided with internal and external inserts to maintain generally U-shaped cross-sectional configuration of the pipe ends. When the pipes are transported to an installation site, the thermoplastic pipe ends with inserts applied match one another, enabling the pipe ends to be fused to one another. Upon locating the pipes within the host pipe, the interior inserts can be removed by floating the inserts through an open end of the pipe or using a “pig” drawn through the pipe.

Abstract: An adaptive multi-stage overload protection system for a crane provides an optimal response dependent upon the magnitude of the crane overload. The control system permits the crane operator to take remedial action for overloads of relatively low magnitude, but automatically reponds to dangerous overload conditions. Under extreme conditions, the hoist line is permitted topay out, but only if less drastic responses have not adequately or timely corrected the overload condition.