What is an enclosed space?
An enclosed space is a space that contains a limited number of openings, entries or exits.
At these spaces the ventilations are unfavorable.
Examples of enclosed spaces include double bottoms, fuel tanks, and empty spaces between bulkheads.
The officer of the watch only gives the authorization of entry after making sure that it is safe.
Before entering on an enclosed space, the officer of the watch needs to make a preliminary inspection to determine the probability of a deficiency of oxygen levels or if there are inflammable or toxic atmospheres.
Only trained personnel should entry these spaces. They must have with them portable VHF so they can communicate with the outside crews.
There must be means to rescue the people who go inside these spaces and a stand-by rescue team.
The atmosphere must be tested before anyone going inside the enclosed space and in regular periods of time during the operations.
Oxygen levels and the reaction they provoke on humans:
- 23.5%- Disorientation, breathing and vision problems;
- 19.5%- Lowest acceptable oxygen levels;
- 15% to 19%- Lower coordination, lower capability of working energetically;
- 12% to 14%- Heavier breathing;
- 10% to 12%- Increased breathing rate and blue lips;
- 8% to 10%- Disorientation, fainting, nausea, loss of conscience;
- 6% to 8%- Permanence for more than 8 minutes is fatal; 6/8 minutes: 50% chances of being fatal; 4/5 minutes: possible recovery.
- 4% to 6%- Coma in 40 seconds; death in 3 minutes.
Precautions after entering the enclosed space:
- Regular atmosphere tests;
- Continuous ventilation;
- When there is any doubt if It’s safe to entry, this should be done only if anyone’s life is at risk or the safety of the ship and crew is on the line;
- Use proper clothes and breathing apparatus.
There must always be a rescue team ready to entry the enclosed space, and must have the following equipment:
- 2 autonomous breathing apparatus;
- 2 bottles of compressed air;
- 2 flashlights;
- Safety harness;
- Safety Lifeline;
- First aid kit;
- Elevation tripod.