Feb 142013

dp2Single fault failures should not be possible in safety critical systems. However, a recent incident in which dynamic positioning failed while divers were underwater show that they can and do happen in ways that, with 20/20 hindsight, are not surprising.

A serious incident occurred in which a diving support vessel’s dynamic positioning (DP) system, designated as IMO class 2, failed resulting in the vessel drifting off position while divers were deployed subsea. Investigations have shown that a probable cause of the DP failure was a single fault which caused blocking of the DP system’s internal data communications. Continue reading »

Dive Fatality – Don’t Use Bailout For Brush

 Accident, Accident report, diving, Safety Alerts  Comments Off on Dive Fatality – Don’t Use Bailout For Brush
Feb 022013
Bailout bottle - do not use for cleaning a hull

Bailout bottle – do not use for cleaning a hull. Photo: www.scubadiving.com

Using a bail-out bottle to power hull cleaning equipment is a bad idea, in this case it resulted in tragedy. According to a safety alert issued by the International Association of Oil and Gas Producers a diver died when his main air supply failed while he was powering a ‘brush cart’ with his bailout bottle.

Says OGP:  “A routine surface supplied diving operation was undertaken to clean marine growth from a vessel hull. This involved using a hull cleaning device with rotating brushes, termed a brush cart, and this also required a diver to guide and operate it.

“The brush cart contained diver operated tooling that was actuated by an air driven piston. Standard company practice was to use the suit inflation take off from the diving mask for this purpose.

Prior to this dive the diving mask was changed to a model that did not contain a suit inflation take off capability.

A decision was made to connect the diver’s emergency gas supply line (Bailout) directly to the brush cart tooling. This resulted in the diver having no personal emergency gas supply.

During the dive the diver’s gas supply line (umbilical) was caught in the wheels of the brushcart and the diver experienced a reduction in breathing gas. The diver, having no emergency gas supply, removed his mask, immediately losing communication to the surface team and was observed in distress at the surface.

The surface team was composed of a radio operator (a diver) and a tender for the diver (non diver) and a diving supervisor who was not on the site at this time. Continue reading »

Safety Alert – Make Sure Third Parties Screw Good

 diving, Safety Alerts  Comments Off on Safety Alert – Make Sure Third Parties Screw Good
Sep 042009

Imperialist burden - imperial thread on gas cylindre

Mismatched threads led to a dangerous smack in the mouth and serious injuries for a diver working for an IMCA member company after a subcontractor’s subcontractor mismatched imperial and metric threads on an emergency gas cylindre and pillar valve after hydrostatic testing.

Luckily the diver made a full recovery and investigation and auditing are underway to forestall similar incidents.

Continue reading »

Safety Alert – Bail-Out Bottles

 diving, offshore, Safety Alerts  Comments Off on Safety Alert – Bail-Out Bottles
Jul 112009
  • Surface air dive to -34fsw
  • Bail-Out bottle contained mixed gas
  • Diver bumps control valve allowing gas to hat
  • Supervisor immediately switches to HP back up air
  • Abort dive – diver to surface – no harm
What Went Wrong?:
  • Content not analyzed – only checked for pressure
Corrective actions and Recommendations:
  • Bail-Out contained 14% HeO2– emptied-charged with air
  • Bail-Out bottles will be analyzed for content at the start of project
  • Bail-Out bottles that are used for mixed gas will be:
    • Supplied by the dive contractor (no personal bottles)
    • All bottles will be color coded
    • All bottles will be labeled with % of mix
  • Pre-Dive Checklist will include a Bail-Out Drill



SAFETY ALERT NO. 213, Oil and Gas Producers