Abstract: Two lifting units (1, 2) have lifting grabs (3) for lifting individual concrete slabs (29) off a prestressing bed on which they have been cast and then stacking them on a pair of support beams (6) to form a pile (28). Once the pile (28) has been formed, the lifting units (1, 2) use lifting hooks (16) contained within an upper frame (14, 15) to lock into the beams (6). A jacking mechanism (13) then raises the upper frames (14, 15) relative to lower frames (11, 12) to lift up the entire pile of slabs (28). The lifting units (1, 2) are mounted on rails (9) which run along the sides of the prestressing bed and lead off to a stockyard where the pile of slabs (28) is taken by the lifting units (1, 2) for storage. During transfer of the individual slabs (29) to the pile (28), drilling units (4) are swung under each slab ( 29) to drill drainage holes. One of the lifting units (1) has a container (21) for dispensing and collecting the beams (6).

Abstract: The invention concerns an apparatus for feeding solid fuel from a storage silo or equivalent to a solid fuel-using heating boiler. The feeding apparatus comprises a piston, which has been disposed to carry out a reciprocating motion within a tube which through an aperture communicates with the solid fuel storage silo or equivalent, and which communicates by its other end with the heating boiler. With a view to accomplishing the feeding of the solid fuel with reliable certainty, before the piston, in the feeding apparatus of the invention there has been provided in the lower part of the storage silo or equivalent, a rotatably disposed vane.