SAFETY ALERT 23

Entry Into Enclosed Spaces

Spaces potentially unsafe for entry - (Update August 2011)

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This Safety Alert provides an update on the number of incidents where dangerous / hazardous atmospheres were identified by MCA surveyors in places which would not normally be considered dangerous after being cleared safe to enter by ship staff.

Case 1 - RORO Ferry Car Deck

During the survey of a RORO ferry on vehicle deck where a number of vehicles (including motor bikes) with engines running were waiting to off load , dangerous concentrations of Carbon Monoxide (CO) were recorded on the MCA surveyor’s personal meter, due to the exhaust emissions of vehicles waiting to unload and inadequate ventilation. It was a normal practice to keep the stern and bow doors open ensuring cross ventilation, but on this occasion only the stern door was opened resulting in a dangerous build up of CO.

Case 2 - Sewage Treatment Plant

During the survey of a Sewage Treatment plant (STP) compartment on board a training ship, dangerous levels of CO and reduced oxygen levels were recorded on the surveyor’s personal meter, despite the STP compartment having been declared ready for entry by the ships’ staff and no evidence of adverse ventilation was observed.

Case 3 - Spaces adjacent to exhaust from heater

A catamaran had been in a dry dock; and had been so for about a week, and all voids had been opened to the fresh air , ventilated and so declared ready for survey . Most of the void spaces were found fit for entry except one, located next to a diesel fired hot air heater fitted on the open deck. It was believed that exhaust from the heater was defective, which led to dangerous CO permeating down the void space possibly through a leaking hatch seal or when the hatch was opened. A similar incident was recorded on another vessel, where high concentrations of CO were detected in ship’s laundry space above the steering compartment where the emergency fire pump exhaust pipe passed and believed to be leaking into the laundry space.

Case 4 - Emergency fire pump space

During a PSC inspection, depleted oxygen levels were found in the compartment containing the emergency fire pump which was located about 13 metres below the open deck and accessed by vertical ladder. Although ship staff declared the compartment fit for entry and ventilation fans were observed as fully operational, subsequent investigations revealed that the fresh air inlet door / hatch was found to be closed; thereby preventing fresh air being drawn into the space.

Further information :

Code of Safe Working Practices for Merchant Seamen Chapter 17

Merchant Shipping (Entry into Dangerous Spaces) Regulations 1988 SI 1998/1638

Your Safety at Sea - Entry Into Enclosed Spaces leaflet Ref. MCA/198

Safety Alert Article 1 - Bulletin 354 - 03/04 - Entry into Enclosed Spaces - A Reminder of  the Dangers - USA

Safety Alert 21 - Entry into enclosed spaces - Spaces potentially unsafe for entry

MGN 423 (M) - Entry into dangerouns spaces

Maritime and Coastguard Agency

Survey Operations Branch

August 2011