A ‘largo’ pontoon was beached at an isolated location for repairs. At one point the person in charge of the pontoon entered a compartment approximately 5 metres deep; there were no checks on the air quality of that compartment before entry. Within a very short time after entering this tank he became unconscious and fell, face down, onto the plates below. One of the two co-workers that had remained outside attempted a rescue and was also rendered unconscious after entering the tank. A third worker then entered the tank and also succumbed.
Seeing the commotion and wanting to help, a man on the beach also entered the space to carry out a rescue and he too became unconscious. In short succession two others entered the tank but also succumbed. After more than an hour a successful rescue attempt was made and all bodies were removed. Resuscitation was attempted at length but of the six who entered the compartment, there was only one survivor.
- A false sense of security may have been acquired by the person in charge as he had entered other tanks earlier without negative consequences.
- Never enter a confined space without first testing the atmosphere from top to bottom.
- Always wear a portable four-gas detector while in a confined space, even once it has passed the initial testing prior to entry.
- Confined space training and practice is essential in order to prevent tragedies such as the above.