Bulk Carrier Practice - Entering enclosed spaces
With kind permission from the author, Capt. Jack Isbester and in association with The Nautical Institute the UK P&I Club, in the interests of its members presents the second edition of the highly acclaimed, Bulk Carrier Practice.
In the coming months the UK P&I Club will be serialising extracts of the book in order to raise awareness of issues in the Bulk Carrier trade.
Entering enclosed spaces
Many serious accidents, some resulting in death, occur on board bulk carriers because safe procedures are not followed when enclosed spaces are entered. Any enclosed unventilated space which can be sealed off from the outside atmosphere may be dangerous and enclosed spaces must be taken to include cargo holds, battery lockers, paint storerooms and masthouses as well as ballast, bunker and cargo tanks.
There have been numerous cases of seafarers entering a cargo hold which is battened down with little or no ventilation and being overcome by lack of oxygen. In November 2006, for example, a Filipino seaman died in Helsingborg from breathing carbon dioxide when he entered a hold laden with wood pellets from Vancouver. In the same incident two other members of the crew, a dock worker and two medics had to be hospitalised216. Only too often deaths have resulted. Particularly dangerous are cargoes which absorb oxygen by rusting, such as pig iron. Seafarers should never rush down into a hold to rescue a shipmate if they see that he has been overcome. A breathing apparatus should always be used and safe procedures must be followed. It cannot be repeated too often that the natural instinct to give immediate help must be resisted.
Two seamen entered a mast house containing access hatches to the holds. The hatches had not been secured and methane from the coal cargo had escaped into the mast house. One of the seamen lit a cigarette. The resulting explosion killed both men. Had no cigarette been involved they could equally well have died through asphyxiation. On another occasion five stevedores entered a hold before the hatches had been opened. The cargo was yellow corn, otherwise known as maize. Much of the corn had started to germinate during the voyage removing oxygen from the atmosphere of the hold. All the stevedores died of oxygen deficiency. Elsewhere a stevedore slipped and fell amongst a cargo of logs in a hold. He was overcome by an atmosphere deficient in oxygen and so were the three colleagues who tried to save him. All were pronounced dead on arrival in hospital201.
Many explosions have occurred in battery lockers due to the use of naked flames from matches and cigarette lighters. Seafarers who enter storerooms such as the lower forecastle store flat after stores have been left unsecured during heavy weather have suffered serious injuries as a consequence of heavy items toppling on to them. The foregoing are illustrations of just some of the dangerous situations which can be met, quite unnecessarily, if correct procedures are not adopted when entering enclosed spaces.
IMO197 has produced detailed and extensive advice and recommendations for entering enclosed spaces. Enclosed spaces and people equipped to evaluate them are defined and the possibility of meeting an unsafe atmosphere is explained. The risk must be assessed, entry authorised, appropriate precautions taken and the atmosphere tested. A space must never, never be entered without precautions when an emergency occurs. When the atmosphere is known to be unsafe additional precautions must be taken to ensure complete safety or the space should not be entered.
Bulk cargoes which are known to cause oxygen depletion (a lack of oxygen) include grain and grain products, oilseeds, copra, all forms of wood, vegetable fibres such as jute, hemp, flax, cotton and many others, fishmeal, guano, sulphidic ores and concentrates, charcoal and coal, dry ice, metal wastes, scrap metal and many more.
Officers should take great care to ensure that all involved have a very clear understanding of the instructions. Bulk carriers are manned by people from many cultures and although it is desirable that all members of a ship’s company should speak the same language this is often not the case. Full discussion of the information and instructions relating to entering enclosed spaces should be encouraged to confirm that they have been understood and to remove the possibility that a rating is accepting an order that he does not understand or thinks it wrong to question. If the officer in charge suspects that someone does not have a full understanding of what is intended, he should not allow him to be part of the team entering the enclosed space.
It is important that enclosed space entry forms are completed at the site of entry and actual readings of oxygen and other gases are clearly recorded on the form. It is not good practice for the enclosed space entry forms to be completed in the ship’s office or be pre-programmed into the computer with all the boxes ticked. These practices are unprofessional and could very easily result in a fatality.
Enclosed spaces should be thoroughly ventilated, using mechanical ventilation when the atmosphere is not explosive and it is safe to do so. The atmosphere should be tested for oxygen and toxic gases before anyone is allowed to enter the space and should be continuously monitored whilst crew members are within. Frequent communication with those inside the tank is vital. Walkie talkies or thunder ball whistles are often used for this purpose. The access to an enclosed space should be fenced off and provided with eye-catching warning notices when it has been opened but not yet proved safe for entry. Safety is just as much a part of the job as the cleaning of the tank, or the repair of a valve, or an inspection.
The tanks of larger bulk carriers are cavernous places with very big brackets, deep frames, floors and stiffeners. It can take 20 minutes to move from end to end of a large double bottom tank, and such tanks may be entered through bulkhead stools or void spaces. A human can be brain dead if deprived of oxygen for four minutes, so the chances of mounting a successful rescue operation for someone who is overcome by lack of oxygen or toxic fumes at a point in the tank remote from the entry manhole are very poor. A useful exercise for inclusion in the ship’s regular safety drills is to practice a rescue from an enclosed space, followed by the appropriate first aid and medical treatment.
Portable fans (Fig. 22.24) are required for the ventilation of enclosed spaces before they are entered. The fans should be used to blow clean air into the space, driving out the foul air through ventilators or other manhole covers at the extreme far end of the space. It is not a good idea to use a fan to suck air from a space as in these circumstances the air in the vicinity of the fan may become explosive or foul.
Available for purchase from The Nautical Institute website www.nautinst.org
The second edition is available to UK P&I Club Members at a discounted rate.
Also included in this offer is the UK P&I Club DVD Bulk Matters. A guide to identifying bulk cargo claims and measures how they may be avoided.