Abstract: A splicing device for concrete structural members includes two mating connectors positioned in axial alignment adjacent to each other that are interlocked by a key inserted through a keyway provided in the sidewalls of the connectors. Prestressing strands in the structural members to be spliced are fastened to the connectors by inserting them into axial holes located in the ends opposite the mating ends of the connectors, and thereafter wedging the strands within frustum-shaped cavities forming part of the holes, by means of frustum-shaped segments, or feathers, forced against the elements within the cavities. Apparatus and a method for installing the splicing device is also described.

Abstract: A pile driver assembly comprising a lead, a hammer supported for longitudinal movement along the lead, a helmet at the lower end of the lead configured to receive the end of a noncircular pile, a pile guide supported for longitudinal movement along the lead and having a cross-section configured to receive the pile, and a pile rotator supported near the lower end of the lead and configured to receive the pile, the pile rotator centering and rotating the noncircular pile.

Abstract: There is disclosed herein a portable crane having a boom and lower brace supporting an elongated lead adapted to carry a pile driver, drill or other tool. The outer end of the brace has a capstan drive connected to a lead supporting line whereby the brace is movable vertically independently of the lead.