AAG submarine cable: burying an in-service cable 5 m deep at −33 m
Divers airlifted a trench beneath a live Asia-America Gateway cable at −33 mPD, letting it sink 5 m into the seabed to −38 mPD.
- Year
- 2009 – 2010
- Location
- KP51, AAG cable route, Hong Kong waters
- Status
- Completed
- Category
- Underwater & marine
At kilometre point 51 on the AAG cable route the cable lay exposed on the seabed at about −33 mPD. It could not be lifted or cut, so the seabed was taken away from under it instead.
A 300 mm airlift with a water-jet nozzle was hung from a float and worked by divers along the cable. As the trench deepened, the cable sank under its own weight until it reached 5 m of cover, with the trench bottom at −38 mPD. A tension meter on the cable kept the load within limits throughout.
The spread on the diving barge: two 600 cfm compressors, two water-jet systems, a diving control room, a decompression chamber and generators, with GPS on the barge and a marker float.
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