Blasting is then carried out using waterproof emulsified dynamite, with between 4 to 8 kg placed per hole/meter. When drilling and blasting close to jetties and walls, the contractor performed controlled blasting with reduced explosive and segment explosion. Seismographic procedures were also undertaken on the jetties.

Underwater drilling must also be done inside the harbour near existing underwater structures that must not be damaged. Often there is a variety of surfaces which require different drilling pressures and, accordingly, compressors must be sufficiently versatile to accommodate the changing demands in occasionally harsh weather conditions, with swells of up to 4m and fast running currents. It is also necessary to contend with 15m of bending casings below the water surface.

New Harbour Engineering Company chose nine barge mounted compressors from Stockholm headquartered Atlas Copco to meet the continuous high pressure air requirement for the underwater drilling tools. The portable diesel compressors provide high pressure compressed air at up to 20 bar. All nine compressors are mounted on two barges to ensure ease of manoeuvrability around the harbour to drill site locations.