Abstract: The invention comprises a load-supporting beam provided with plates at each end which are pivotally mounted to pendants at each end, to which pendants are attached the suspending cables. Each pendant carries a hydraulic cylinder attached at one end to the pendant and at the other end to a crank affixed to the rotating element carrying the pivot for the load. That element is provided with an indexing pin which fits movably in a slot in the adjoining beam end plate. That end plate also has a second slot in line with the slot first mentioned, through which second slot passes the pivot bolt which also passes through the center of rotation of the rotating member. The center of gravity of the rotating load carrier is brought into alignment with the axis of rotation by adjusting the position of the indexing pin and the pivot bolt in the end plate slots.

Abstract: A method and apparatus for eliminating the necessity of providing hold-down devices, such as spuds and anchors, for opposing buoyancy in tunnel forms. The method comprises providing a movable counterweight car which preceeds the flow of fluid concretes, as it slopes from the crown of the tunnel forms downward and thus provides negative buoyancy at that area where there is the most fluid concrete and in that area where the most uplift occurs as well as the natural area where there are no forces of the crown helping to prevent flotation. The movable counterweight car is a hollow container curved to match the curvature of the excavated tunnel and clearing the movement of the forms. It has wheels that run on single track rails carried on the inside of the tunnel forms, the container being wholly or partly filled with steel scrap or punchings.