Method of mounting ventilation shaft made of several sections onto roof

摘要

The method involves a motorised cable winch (3) being secured to a loops (5) on one side and to dowels on the other side. The shaft sections are assembled on the ground before being raised to the roof (2). The winch's cables (4) run under the shaft (1) and are then suspended from the loops by their other free ends. The shaft is then hoisted by the winch to the roof and positioned. Finally the winch and loops are removed and the shaft is fixed in place.