Another manager has sent us a report of a hazardous incident that resulted from an improper change to the equipment on a tanker . It was found that a drain pipe from the accommodation air conditioning unit had been plumbed in to the drain for the inert gas system. (The inert gas system provides a protective blanket of inert gas, mainly nitrogen, to the cargo tanks.) The A/C drain had originally been connected to the bilge holding tank. However, whilst the ship was under the previous management of another company, it had been modified to discharge into the inert gas drain line.
As a result of the connection between the two systems, there was a risk that inert gas could have been blown into the accommodation via the air conditioning unit.
Whilst this report may at first sight seem highly specific, it does highlight that all changes to equipment, systems and procedures need to be carried out in the discipline of a robust change management procedure that is strictly applied. The procedure will include technical consideration of every proposed change, and proper authorisation. The change management procedure is a key part of the Safety Management System.