Seawater pump houses: installing trash screens
Divers set 11–16 m wide screen frames against the seawall at three seawater pump houses, drilling and welding underwater to close every gap.
- Year
- 2010
- Client
- Penta-Ocean Construction; Chun Wo Construction
- Location
- Cha Kwo Ling, Tai Wan Shan and Wan Chai East
- Status
- Completed
- Category
- Hydraulic
A seawater pump house needs a screen in front of its intake to keep rubbish out of the pumps. At Cha Kwo Ling, Tai Wan Shan in Hung Hom and Wan Chai East, the frames had to fit the face of an old blockwork seawall from +4.5 down to −4.4 PD.
- Rig five chain-block points on shore.
- Lower the frame by crane, with divers directing it into position.
- Clean the marine growth off the seawall.
- Drill the bases underwater with a CP9 drill and fix them with M12 expansion bolts; drill the top fixings from shore.
- Measure the remaining gaps. Weld 3 mm steel plate underwater over the larger ones and close the small ones with marine putty.
At Wan Chai the temporary screen rails were fitted, marked with chalk, taken ashore to be trimmed, then re-set and drilled.
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