Log cargoes are prone to decomposition whilst en route. The process of decomposition results in a depletion of oxygen in the surrounding area. When this occurs in a ship's hold a dangerously low O2 atmosphere is created in the hold. This is the hidden danger of carrying log cargoes.
This is precisely what befell two Korean seamen on board a vessel moored at Port Marsden, Wellington New Zealand last May. The vessel was ill prepared to carry logs as it was found after investigation that the crew were unaware of the dangers of carrying logs, had no rescue training and lacked basic emergency skills.
The chief officer lost consciousness while he was climbing into the ship's hold and fell from the ladder onto the logs below. The crew member who tried to save him also passed out, fell and died within minutes.
It was later discovered that the sailors were killed by a lack of oxygen and the presence of toxic gases caused by the organic decomposition of logs. The oxygen levels in the hold were between 1% ~ 3% low enough to cause unconsciousness in seconds.
There are many published recommendations and warnings regarding the carriage of log cargoes and the Club would wish to reinforce to Members that such advice should always be sought before carrying such cargoes.
This notice is in addition to the previously issued Bulletin 630 (“Carriage of logs – Fatality” issued 03/09) Mention should be made to the inexperience and lack of training of the crew which contributed to this accident but the main purpose of this Bulletin is to highlight the hidden dangers of log cargoes and to reinforce the fact that many cargoes that may seem benign may in fact have dangerous qualities when transported by sea.
Source of Information:
Loss Prevention Dept.
UK P&I Club