Abstract: Draft tube embedments of a hydroelectric turbine are removed for replacement and/or upgrading. Several shafts for saw wire access, forming a horizontal polygonal shape are drilled outside the draft ring and a circular slot cut below the bottom ring to meet the shafts. Shafts and slot encompass the embedments. Additional shafts are drilled for hoist slings. Generally radial cuts are made using diamond saw wires attached to saw wire machines from selected saw wire access shafts to the draft tube through the embedments. Back cuts are made between adjacent saw wire access shafts, again by diamond saw wires attached to saw wire machines, cutting the polygon into sections. Hoisting slings are passed down the hoisting sling shafts around the sections. The sections are then cut free by further back cuts and then hoisted from the draft tube. The method is quicker than conventional methods.

Abstract: This invention relates to a method of cutting and removing a nuclear reactor which includes the pressure-feeding of a grouting material into a pressure vessel and to peripheral members outside the pressure vessel so as to integrate and solidify them, and the cutting of the structure starting with the outer periphery of the pressure vessel. When the cutting operation is carried out, the present invention preferably uses a wire saw having diamond grains on the surface thereof, and further performs double cutting by the use of a preceding cutting edge and a cutting groove width adjustment cutting edge when the cutting operation is made. In this way, the pressure vessel of the nuclear reactor can be dismantled and removed safely and efficiently.

Abstract: The invention relates to a method of cutting an interior surface in reinforced concrete. Holes are drilled to define the shape of the concrete (usually a rectangular block) to be removed, these can be drilled to any suitable depth, which was not possible under prior art methods. Slots are cut between the holes except at one side using an endless wire saw. An interior cut is made using the endless wire saw from the periphery to the uncut side. The wire saw is secured in the cutting operations at the interior end of the holes by swivel pulleys secured at the exterior end of the holes to the concrete surface. The invention also relates to a swivel pulley assembly especially adapted for application in the method. The invention further relates to a method of cutting a substrate by allowing the wire saw to cut between two pulleys interior of the substrate, from a nonlinear path between the pulleys to a line connecting the pulleys.