A member has reported an incident during a ‘routine’ operation on a diving support vessel (DSV) where a diving bell had been surfaced from 140msw for maintenance. The bell had been returned to atmospheric pressure and the surface stand-by diver had been tasked with opening the door of the surfaced bell and inserting an air hose to be used to flush out the residual diving gas (4% O2 in He) to ensure a breathable atmosphere in the bell prior to personnel entering it.
Having opened the bell door the stand-by diver stood up and started to climb into the bell. He immediately started to suffer the effects of oxygen starvation, became confused and fell out of the bell. Due to the hypoxic effect of the bell atmosphere the stand-by diver lost consciousness for a short period of time on deck in the bell hanger area.
He recovered quickly with no apparen’t ill effects and had regained consciousness without the need for resuscitation before the medic arrived on the scene.
The member noted that entry into recently surfaced diving bells and chambers was a potentially hazardous activity despite the fact it is considered to be a ‘routine’ task.
The member issued instructions that personnel on all diving worksites should be made aware of this potentially serious incident and should take steps to ensure that low oxygen hazards are identified and suitably addressed (by access control, flushing and atmospheric monitoring) before any person was permitted to enter either a bell or a chamber that has recently been surfaced.
Members are reminded of the importance of robust confined space entry procedures.
IMCA Safety Flashes summarise key safety matters and incidents, allowing lessons to be more easily learnt for the benefit of all. The effectiveness of the IMCA Safety Flash system depends on Members sharing information and so avoiding repeat incidents. Please consider adding [email protected] to your internal distribution list for safety alerts or manually submitting information on incidents you consider may be relevant. All information is anonymised or sanitised, as appropriate.
IMCA’s store terms and conditions (https://www.imca-int.com/legal-notices/terms/) apply to all downloads from IMCA’s website, including this document.
IMCA makes every effort to ensure the accuracy and reliability of the data contained in the documents it publishes, but IMCA shall not be liable for any guidance and/or recommendation and/or statement herein contained. The information contained in this document does not fulfil or replace any individual’s or Member's legal, regulatory or other duties or obligations in respect of their operations. Individuals and Members remain solely responsible for the safe, lawful and proper conduct of their operations.