New IMCA Diving guidance on lost bell emergencies

IMCA has published new guidance on lost bell emergencies. Guidance on prevention and mitigation of lost bell emergencies (IMCA D077) draw together our key advice on the subject into a single up-to-date guidance document.

A potential significant risk when using closed diving bells is that the diving bell and its divers cannot be recovered, either because the main lift wire, secondary lift wire(s) and main umbilical are severed, or because the bell is trapped. Such an incident is referred to as a ‘lost bell’ if supplies of breathing gas or heating from the surface are lost.

It is recognised that a lost diving bell incident is a rare occurrence, but one which is life-threatening for the divers. Previous lost bell incidents have proved fatal.

IMCA D077 collates material previously contained in several AODC and IMCA documents to provide updated guidance on the prevention and mitigation of lost bell diving incidents, superseding previously published guidance contained in the following documents which have now been withdrawn:

• Emergency Isolation of Gas Circuits in The Event of a Ruptured Bell Umbilical (AODC 009).
• Bell Emergency Location Equipment Trials (AODC 012).
• Emergency Procedures – Provisions to be Included for Diving Bell Recovery (AODC 019).
• Bell Ballast Release Systems and Buoyant Ascent in Offshore Diving Operations (AODC 061).

Bryan McGlinchy, Former Diving Manager, IMCA said: “The publication of IMCA D077 pulls together the Association’s key advice on lost bell emergencies into a single document, making appropriate guidance on this important and complex topic even more accessible for IMCA Members and other stakeholders.

“Following the up-to-date guidance should prevent lost bell emergencies from happening. Even so, divers and those managing diving operations should not be complacent. The information and guidance set out in IMCA D077 will help them prepare for, and deal effectively with, a lost bell emergency.”