Alert
  • Published: 3 Jun 2024

Diver’s umbilical trapped during a pipeline flooding operation

Divers umbilical trapped during a pipeline flooding operation
Divers umbilical trapped during a pipeline flooding operation

Description of Incident

A saturation diver lost his breathing gas supply and had to go onto his emergency cylinder. The incident occurred on a moored 8-point construction barge during flooding operations near the pulling head of a newly laid pipeline. Water depth at the platform was 53 msw.

The pulling head of the newly laid line was in close proximity to another pipeline approximately 1.5m off seabed. Local arrangements consisted of a quarter turn valve and diffuser at the pulling head. Shortly after initiating the flooding, Diver 1 reported ”All Stop” as the pipeline shifted horizontally by approximately 1.5m. Diver 1 umbilical became trapped between two pipelines resulting in a lost video signal, a restriction of breathing gas and only 1 m of umbilical available for manoeuvring.

As Diver 2 approached to help, Diver 1 lost gas and went on his emergency gas cylinder. Diver 2 then provided pneumo gas to Diver 1 who turned off his “Bail-Out” to conserve emergency gas. Both divers worked in tandem to reconnect the pipe, lift it, and clear the umbilical. Once freed, breathing gas was restored to Diver 1 with 210 bar remaining in his “Bail Out Bottle”. Both divers were able to return to the bell.

Visibility was 1 to 2m with a significant but not excessive tidal current of 0.75 -1 kt.

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