What are the MARPOL discharge criteria for a Framo-pumped cargo, and how is a tank stripped step by step?
Short answer
| Annex I regulation 34 criterion | Limit |
|---|---|
| Location | not in a special area, more than 50 nautical miles from the nearest land |
| Ship | proceeding en route |
| Instantaneous rate | not exceeding 30 litres per nautical mile |
| Total quantity | not exceeding 1/30,000 of the cargo (1/15,000 for tankers delivered before 31 December 1979) |
| Equipment | ODMCS and the slop tank arrangement operating |
- Framo pump: a hydraulically driven deepwell centrifugal pump at the bottom of each cargo tank, powered from the engine-room hydraulic power pack; suction at the lowest point.
- Stripping: as the pump loses suction, run it in stripping mode (reduced hydraulic flow); use the stripping line and eductor for the tank bottom and line low points; residue to shore or the slop tank.
- Oil tanker, Annex I regulation 34: not in a special area, more than 50 nautical miles from land, en route, not over 30 litres per nautical mile, total not over 1/30,000 of the cargo, ODMCS operating.
- Chemical tanker, Annex II: strip to the required residue, prewash for the higher-hazard categories, discharge at the prescribed distance, depth and speed.
- Link: good stripping minimises residue; recorded in the Oil Record Book Part II or the Cargo Record Book.
- As Chief Engineer: the hydraulic power pack and the ODMCS are mine; nothing goes overboard outside the criteria.
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.