NATARAJACare of the cargo — sweat, segregation & hatches
Learning outcomes & permitted supports
- Make the ventilation decision from dew points alone — and name which sweat you are preventing
- State what each segregation term demands in steel and metres, and apply it to a stowage
- Walk a hatch-cover weather-tightness inspection as a system: seal, drains, compression, alignment, proof
- Explain ship sweat vs cargo sweat by voyage direction, in one breath
Supports in this lab: No instruments needed. Dew points computed by the engine's Magnus implementation (golden 840/840); segregation trainer is a stated training simplification — the IMDG Code governs aboard.
Ventilation & sweat — the dew point decides, nothing else
Outside air 30°C at 80% RH → dew point 26.2°C. Hold air 22°C at 70% RH → dew point 16.3°C.
DO NOT VENTILATE — outside dew point is at or above the hold's: you would carry moisture in, to condense on the coolest steel (ship sweat).
The two sweats, one rule: on a warm→cold passage the HOLD air is the moist one — it finds the ship's cooling steel: ship sweat (ventilate when the outside dew point allows). On a cold→warm passage the OUTSIDE air is the moist one — admit it and it finds the still-cold cargo: cargo sweat (keep the hold shut). Compare dew points, not temperatures: warm air can be drier than cold air.
| Dew point outside / hold | 26.2 / 16.3 °C |
|---|---|
| Decision | hold shut |
Segregation — what the words demand in steel and metres
Pick two classes; the trainer states the segregation term and what it physically requires. Training simplification — aboard, the IMDG Code's own tables and the ship's Document of Compliance govern, schedule by schedule.
| Requirement | Separated from |
|---|---|
| Which means | Different compartments or holds; on deck, at least 6 m apart. A steel deck between them counts vertically. |
Hatch covers — weather-tightness is a system, inspect it as one
Tap each item; the checklist remembers what you have walked.
Inspected 0 of 5.