Use of breathing apparatus
Governing: STCW Table A-VI/1-2 ("use of breathing apparatus for fire fighting"); REG Yacht Code Table 15A.1. Builds on: L3.3.
Breathing apparatus lets a firefighter enter smoke. It also lets a careless one walk further into danger than they can get out of. The discipline around BA matters as much as the kit.
How SCBA works
Yacht fireman's outfits carry self-contained breathing apparatus, open-circuit compressed air:
| Component | Job |
|---|---|
| Cylinder | Stores compressed breathing air |
| Cylinder valve | Opens the supply |
| Pressure reducer | Drops high cylinder pressure to a medium pressure |
| Demand valve | Delivers air to the mask as you breathe, usually at slight positive pressure |
| Face mask | Seals around the face; visor, speech diaphragm |
| Pressure gauge | Shows remaining cylinder pressure, and so remaining air |
| Low-pressure warning | A whistle that sounds when pressure falls to a set level |
| Harness | Carries the set |
Air consumption rises steeply with effort, heat and stress. The duration printed on a set is for a calm person; in a fire you will use it much faster. This course does not give durations or pressures; they depend on the set and are taught on the practical course.
Checks before use
- Visual: harness, straps, mask, hoses, cylinder in date.
- Cylinder contents: open the valve and read the gauge. It should be full.
- High-pressure leak test: close the valve and watch the gauge; it should hold.
- Warning whistle test: vent slowly and confirm the whistle sounds at the set point.
- Face seal: don the mask and check it seals, with no hair or spectacle arms under it.
- Buddy check: each wearer checks the other.
Discipline in use
- Never alone. Wearers enter, work and leave as a team of at least two.
- Entry control. Someone outside records names, time of entry, and cylinder pressures, and works out when each team must be out.
- Plan your exit. The team turns back based on the lowest gauge, with enough air to get out along the route in, which may be slower than coming in.
- Stay connected. Lifeline or guideline, and physical contact with your partner in zero visibility.
- Search systematically. Keep a hand on the bulkhead, work one side, and do not pass doors unchecked.
- Communicate. Radio to entry control at set intervals and at every change.
- Withdraw on the first whistle, on the planned time, on the order, or if anything goes wrong.
WARNING — The first whistle means the team If either partner's whistle sounds, both withdraw together. Nobody walks out alone.
After use
- Report cylinder pressure on exit.
- Replace or recharge the cylinder; REG Yacht Code Table 15A.1 requires onboard recharging or two spare cylinders per set.
- Clean and disinfect the mask; check the set before restowing it.
Lithium-ion smoke
MGN 681 advises SCBA whenever anyone may be exposed to smoke from a Li-ion battery fire, because it can contain hydrogen fluoride, which penetrates clothing and causes chemical burns. Decontamination of wearers and kit afterwards is part of the procedure.
CAUTION — EEBDs are not BA Emergency escape breathing devices give a short supply of air for escape. They are not for firefighting, search or rescue.
TIP — Know your breathing rate On every drill, note your start and finish pressures and the time. You will learn how quickly you use air under effort.