QUESTION 6.6.2

ODME integrity, operation and discharge records

Oil, ChemicalPumproom, Main Deck, Cargo Control Room

What is being checked

The inspector is checking whether the ODME is intact, maintained and competently operated so cargo-area discharges remain within MARPOL Annex I, with reliable sensor inputs, automatic control and retrievable records.

Ready onboard

0/8 complete

PROCEDUREThe procedure defines authorised modes, compatible mixtures, test and calibration, discharge controls, failure response and records.CONDITIONMonitor, analyser, sampling system, flow and speed inputs, position input, recorder, valves and automatic control are operational.INTEGRITYNo unapproved modification, bypass or unexplained connection is present.TESTINGMaintenance, test runs and calibration functions follow the manufacturer manual and company schedule.DATAStored or printed ODME data are legible, retrievable and retained for the required period.RECONCILIATIONODME records agree with ORB Part II, slop-tank history, cargo records and bridge positions.MODESManual mode or manual data inputs are controlled and never used for discharge without required shore authorisation.FAILUREOut-of-service periods, repairs and any permitted alternative arrangements are reported and recorded.

Practice questions

Answer aloud, then open the preparation point.

1Demonstrate an ODME test run and explain each data input used to calculate discharge rate.

Follow the maker's test function and identify oil concentration, flow, ship speed, position and control output without initiating an actual discharge.

2When may manual mode or a manual data input be used?

Only under the exact approved procedure and required shore authorisation; it must not become a routine means of overboard discharge.

3How do you confirm the mixture is compatible with the fitted oil-content sensor?

Check the approved sensor capability, cargo history and manufacturer limitations before selecting the discharge route.

4Trace the latest slop discharge from tank to ODME record and ORB Part II.

Reconcile tank, quantity, start and stop times, positions, concentration, instantaneous discharge rate, total quantity and signed statutory entry.

5What is the response if the ODME fails before or during a planned discharge?

Stop or prevent overboard discharge, secure the route, notify the Master and company, record the outage and use only an approved alternative disposal arrangement.

Where an observation may arise

PROCEDURE

Operating modes, compatible mixtures or failure actions are not adequately controlled.

CONDITION

A sensor, sampling component, input, recorder, valve or automatic-control function is defective.

INTEGRITY

The system appears modified, bypassed or fitted with an unapproved connection.

MANUAL MODE

Overboard discharge occurred with manual mode or manual inputs without required authorisation.

DATA

Printed data are illegible or stored records cannot be retrieved.

RECONCILIATION

ODME data conflict with ORB Part II, cargo records, slop quantities or bridge positions.

FAILURE RECORD

An outage or return to service was not recorded and reported as required.

Master's practical note

Treat the ODME record as an independent operational timeline. Compare it with slop-tank quantities, valve line-up, bridge position and ORB Part II; a technically working monitor can still expose a weak record chain.

Equipment boundary and references

Equipment boundary: Sensor compatibility, calibration and control logic are equipment-specific. Use the approved ODME manual and do not initiate an actual discharge solely for inspection demonstration.

References

OCIMF SIRE 2.0 Question Library Part 1, Version 1.0, Question 6.6.2
MARPOL Annex I
IMO Resolution MEPC.108(49), as amended
Manufacturer's ODME operation and maintenance manual

Last reviewed: 2026-09-08