The International Society for Trenchless Technology

A percussive hammer attached to an open end casing is driven through the ground. The spoil within the casing is removed to leave an open casing.

Downhole tools used to enlarge the bore sufficiently to facilitate installation of the product.

A joint which is formed within the thickness of a pipe wall.

Excavated shaft at the end of a jacked section from which the jacking shield is recovered.

All measures for restoring or upgrading the performance of existing utility systems including renovation, replacement or repair to overcome problems related to any aspect of performance.

Method of backfilling, compaction and re-surfacing of any excavation to restore the surface and underlying structure to enable it to perform its original function.

Methods of rehabilitation that incorporates all or part of the original fabric of a host pipe to improve the performance of the pipe

Trenchless construction procedures to restore or improve the structural integrity and / or performance of the utility.

Construction of a new pipe or underground utility located on or off the line of the existing systems, which serves the same function as the old system.

Preparatory operation in which an expansion device is inserted into a distorted pipe to return it to a circular cross section. Rerounding is usually carried out prior to the insertion of a permanent liner or supporting band.

Localised repair of pipes, usually sewers, by injection into cracks, defects or cavities a resin formulation which subsequently cures to prevent leakage and further deterioration.

Remote control device with closed circuit television (CCTV) monitoring, used mainly in localised repair work, such as cutting away obstructions, re-opening lateral connections, grinding and re-filling defective areas and injecting resin into cracks and cavities.