A five year term contract offered ample opportunity to fine hone working practises on this potentially hazardous project. The port remained operational except in the localised areas handed over to our main contractor, but that did not stop interface problems with shipping and day to day port operations.

Low headroom beneath the jetty was negated by the use of work boats with additional ballast to enable them to sit lower in the water and offer increased working height for the breakout, preparation and sprayed concrete reinstatement crews. 

The main issue with this was the wake from shipping could potentially overwhelm the work boats. Instructions were issued by the Port Authority to shipping in the hope of mitigating the effects from bow waves, but not all crews adhered to the directive, which meant that the work boats ended up on the sea bed occasionally, which obviously represented a major safety issue. 

This was ultimately resolved by stricter controls imposed by the Port Authority, a more prescribed works programme to sequence the works, and a higher level of active awareness and observation by our crews.

Marine environments always pose the same issues, tidal erosion, aggressive chloride attack on mild steel reinforcing mesh, and the subsequent spalling of concrete, freeze/thaw and exposure to unpredictable weather conditions due to their geographical locations. 

To prevent excessive oxidisation of the exposed steelwork following the hydro-demolition and shot-blasting process, the works programme required all exposed repair areas to be reinstated within a 24.00hr period, using a proprietary R4 high performance fast set dry spray concrete.