Abstract: Material lining the inside surface of a section of pipe is removed by a hydrodemolition nozzle assembly mounted on a working end of an elongated boom. The opposed end of the boom is supported outside the pipe on a movable support for inserting and retracting the boom from the inside of the pipe. The nozzles remove the liner while the working end of the boom is supported by a wheel resting on the liner that has not yet been removed and that rolls along the inside liner as the pipe is made to revolve around the boom. The nozzles are oriented to eject the liner and water downstream and away from the boom.

Abstract: A shield system for a hydrodemolition apparatus has a loop whose ends are secured to opposite sides of a reciprocating nozzle carrier. The loop may be supported by a supporting structure surrounding the frame along which the nozzle carrier reciprocates. The loop overlays portions of one or more gaps through which one or more nozzles extend to work an underlying surface. The nozzles have access to the underlying surface through the gaps under the nozzle carrier, but the balance of the gaps are covered by the loop which is drawn or pushed by the nozzle carrier during reciprocation.

Abstract: A shield system for a hydrodemolition apparatus has a loop whose ends are secured to opposite sides of a reciprocating nozzle carrier. The loop may be supported by a supporting structure surrounding the frame along which the nozzle carrier reciprocates. The loop overlays portions of one or more gaps through which one or more nozzles extend to work an underlying surface. The nozzles have access to the underlying surface through the gaps under the nozzle carrier, but the balance of the gaps are covered by the loop which is drawn or pushed by the nozzle carrier during reciprocation.

Abstract: Material lining the inside surface of a section of pipe is removed by a hydrodemolition nozzle assembly mounted on a working end of an elongated boom. The opposed end of the boom is supported outside the pipe on a movable support for inserting and retracting the boom from the inside of the pipe. The nozzles remove the liner while the working end of the boom is supported by a wheel resting on the liner that has not yet been removed and that rolls along the inside liner as the pipe is made to revolve around the boom. The nozzles are oriented to eject the liner and water downstream and away from the boom.

Abstract: A steeply inclined surface is hydrodemolished by providing a staging platform and a rig that includes a base frame defining a planar footprint within the frame. The rig is suspended from the platform by a cable such that frame is coplanar with the surface and the incline of the surface causes the rig to lean against it. Rails are provided on the surface to restrain spurious lateral movement of the rig. The rig is positioned on the surface and nozzles mounted on a trolley within a travelling carriage on the frame travel in two dimensions to hydrodemolish the surface within the footprint. The rig is moved vertically along the rails and laterally along the platform to reposition the rig to work a new section of the surface in conjunction with other rails that are also mounted on the surface.

Abstract: Apparatus for removing material lining the inside surface of a cylindrical structure, the apparatus comprising: a support for supporting the structure in a horizontal orientation; an elongate horizontal boom for being inserted into the structure; a nozzle assembly connected to the boom member, the nozzle assembly comprising one or more nozzles wherein each nozzle is suitably spaced from the lining to deliver a jet of fluid under pressure to the lining; a conduit in fluid communication with the nozzle assembly suitable for delivering a flow of fluid to each nozzle under sufficient pressure to cut the lining material adjacent the nozzle; and a rotation mechanism cooperating with the support to passively enable the structure to being rotated while supported by the support or to actively impart rotation to the structure while supported by the support, wherein the rotation of the structure is about a central longitudinal axis of the structure.