Operational Guide · Registers & Logbooks

# Reefer Container Monitoring

Temperature-controlled cargo is unforgiving: a gap in temperature recording can mean the total loss of the commercial value of the contents.

reefer refrigerated containers cold chain monitoring

## Operational Explanation

Refrigerated containers (reefers) carry perishable or pharmaceutical goods that require a constant temperature (set point) to be maintained for the entire duration of the voyage: any prolonged interruption of the electrical supply or of the cooling unit's operation can irremediably compromise the commercial value of the cargo.

Monitoring relies on two complementary approaches: stand-alone data loggers installed inside the container, which record temperature at regular intervals but require physical retrieval of the device for data analysis, and telematics systems integrated into the cooling unit, which transmit data in real time via cellular or satellite network and allow remote temperature adjustment.

The industry trend is towards continuous, structured electronic records with no gaps, replacing traditional periodic manual checks: this reduces the risk of gaps in temperature traceability, which is particularly critical for the pharmaceutical cold chain.

## Regulatory Reference

Requirements applicable through SOLAS for the electrical supply and safety of the ship's reefer installations; container construction standards under ISO 1496-2; for pharmaceutical transport, reference to the WHO Good Distribution Practices (GDP) for temperature-sensitive products, in addition to the shipper's contractual specifications (set point, tolerances, ventilation).

## Scope of Application

Every container ship or multipurpose ship with reefer plugs on board, for the carriage of perishable goods, pharmaceuticals or other temperature-controlled cargo in refrigerated containers.

## Procedure / How to Complete It

1. Verify at the time of loading that every reefer container is correctly connected to the ship's electrical supply and set to the set point requested by the shipper.
2. Carry out daily temperature and alarm checks on every reefer container on board, verifying that they are operating at the specified set point.
3. Investigate and record every temperature alarm immediately, documenting the cause, duration and corrective action applied.
4. For containers with telematics systems, monitor the data transmitted in real time and intervene remotely where possible before any damage to the cargo occurs.
5. Retain the retrieved temperature logs (data logger or telematics) as supporting documentation in case of a dispute over the quality of the cargo at destination.

## Practical Example

Example management case: a reefer container carrying temperature-sensitive pharmaceuticals generates an alarm for deviation from the set point during the voyage; the crew immediately verifies the cause (a temporary unit malfunction), restores operation within a limited time and documents the entire event with the logger data, allowing the shipper to assess the integrity of the cargo at destination.

## Real Cases

Commercial disputes over perishable goods arriving at destination out of specification are often caused not so much by an actual reefer unit malfunction, but by an incomplete or gap-ridden temperature record, which prevented the real duration and extent of the deviation suffered by the cargo from being demonstrated.

## Common Mistakes Mistake Library

Mistake | Consequence | How to avoid it
--- | --- | ---
Daily temperature checks recorded generically, without a time stamp | Inability to demonstrate the real extent of a deviation in case of a dispute | Record checks and alarms with a precise time and details of the cause
Temperature alarm detected but not promptly investigated | A prolonged deviation not corrected in time | Investigate and correct every temperature alarm immediately upon detection
Data logger log not retrieved or not retained after discharge | No documentary evidence in the event of a commercial dispute | Always retrieve and archive the temperature logs before returning the container

## PSC Observations

Reefer monitoring is not typically subject to direct PSC verification, but the reliability of the ship's electrical supply for the reefer plugs may be checked as part of the general checks on the ship's electrical system.

## Operational Tips

- Record every temperature check with a precise time, not generically: it is the evidence needed in case of a dispute.
- Investigate and correct every temperature alarm as soon as it is detected, without waiting for the next daily check.
- Always retrieve and archive the data logger logs before returning the container to the shipper.

## Checklist

- Reefer containers connected and set to the required set point at the time of loading
- Daily temperature and alarm checks carried out and recorded with a time stamp
- Every alarm investigated and corrected promptly, with the cause documented
- Telematics systems monitored in real time where available
- Temperature logs retrieved and archived before discharge

## FAQ

What is the difference between a data logger and a telematics system for reefer monitoring?
The data logger is a stand-alone device that records temperature at regular intervals but requires physical retrieval for analysis; the telematics system transmits data in real time via cellular or satellite network and allows remote temperature adjustment.
What should be done when a reefer container generates a temperature alarm?
Immediately investigate the cause, act to restore the correct set point as quickly as possible, and document the entire event (duration, cause, corrective action) for any subsequent verification.
Why retain the temperature logs even after the container is discharged?
Because they constitute the main documentary evidence in the event of a commercial dispute over the quality of the cargo at destination, demonstrating whether and for how long any deviation from the set point occurred.
🎬 Additional photos, videos and interactive diagrams for this topic will be available in a future version of the platform.

## Related Topics

Loading/Discharging Plan Managing Cargo Claims

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