Abstract: A method for testing timbers, such as railway sleepers, for disconformities or decay by inducing vibrations in the timber, for example with an impactor monitored by an accelerometer mounted on it and connected to a microprocessor and a display unit to give an indication of constant impact, detecting said vibrations by one or more transducers, amplifying and digitizing the transducer output and microprocessor-processing the digitized output to give an indication of disconformity or decay. One embodiment utilizes the comparison of the first half-cycle surface vibrations and shear vibrations. Another embodiment compares frequency domain information with a memory stored standard. The apparatus, comprising transducers, impactor, microprocessor and indicator is readily portable.

Abstract: A method for lining a pipe such as a sewer pipe by applying to the interior of the pipe a layer of a settable composition including a mixture of one or more organic resins with one or more inorganic filling materials, thereafter covering the surface of the said layer with sheet material and thereafter compacting the said layer onto the pipe by exerting pressure thereon through the sheet material, the sheet material being in the form of a tube of polyethylene film or other polymeric film and in that the tube is removed after the pipe lining composition has at least partly set by pulling one end thereof through the interior length of the lined pipe.