Gammon Construction Limited

A new method devised by the Gammon Plant Department — the Abrasive Waterjet Cutting System (AWCS) for Underwater Pile Decommissioning — has received the Champion award in the IMechE Mechanical Innovation Award 2021–2022 competition.

The AWCS is a novel in-pipe trimming method for submerged clutch pipe piles used in the excavation works of underwater tunnel projects with trimming level below seabed. Traditionally, this would have been done by undersea divers using flame cutters or diamond wire saws after dredging. The AWCS not only dramatically speeds up the trimming process through neglecting dredging, but also achieves smoother cutting edges as well as savings in material costs and fewer dredging plant operations. Worker safety is also significantly increased.

Gammon applied this method in a sub-sea tunnel project, where more than 100 clutch pipe piles were trimmed, a record for sub-sea underground in-pile cutting in South-East Asia.

In addition to winning the IMechE award, Gammon has been granted two patents for the AWCS which was developed through a One Team approach, involving its Construction Services Department and operations teams from the Civil and Foundations divisions. Their support ensured sufficient resources were put into the research and development of the AWCS from early stage feasibility study and experiments to full-scale site trial verification for its final release.

The IMechE – Hong Kong Branch Mechanical Innovation Award competition (formerly known as Best Project Award) has been held annually since 2014 to recognise project works that make substantial contributions to the advancement of mechanical engineering in Hong Kong. Gammon had been the winner of The 4th Year Best Project Award in 2017-2018 : “DfMA in construction - Steelwork projects for West Kowloon Cultural District”

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Gammon wins top IMechE award for new pile trimming method