How is propane carried and used as fuel, and which code governs it?
Short answer
| Feature | IGF Code chapter | What it does |
|---|---|---|
| Arrangement | 5 | tank, fuel-preparation room and piping segregated from accommodation and ignition sources |
| Type C pressure tank | 6 | pressurised liquid, relief valves, secondary containment |
| Double-walled or ducted piping, master gas valve, double-block-and-bleed | 9 | an inner-pipe leak is contained and detected |
| Gas detection sited low, alarms, ESD | 15 | shuts the master gas valve and trips the consumers |
- Framework: the IGF Code (MSC.391(95)), mandatory under SOLAS II-1 part G from 1 January 2017: goal-based, double-barrier, no single failure releases gas to ignition.
- Propane hazard: LPG vapour is heavier than air (relative density about 1.5) and pools low; stored as a pressurised liquid, not cryogenic.
- Arrangement and containment (chapters 5 and 6): tank, fuel room and piping segregated from ignition sources; a type C pressure tank with relief valves and secondary containment.
- Fuel supply (chapter 9): double-walled or ducted piping through gas-safe spaces, ventilated and gas-detected, master gas valve and double-block-and-bleed.
- Control (chapter 15): gas detection sited for low-lying LPG, alarms and emergency shutdown (ESD); Ex-certified equipment, purging before maintenance, IGF-trained engineers.
- Caveat: written around LNG; LPG as fuel uses the alternative-design route and the IMO interim guidelines; an LPG carrier burning its cargo also meets the IGC Code.
- As Chief Engineer: right hardware; the missing anchor is the IGF Code and the heavier-than-air point.
Full answer
The full answer explains each point step by step, with the regulations and figures behind it and the discussion from other candidates. It is in the MEO Class I section of the Marine One forum, open to members enrolled for the MEO Class I exam.