Reserve Battery Capacity in Sea Area A3
An 8,500 GT product tanker operates in Sea Area A3. Its GMDSS installation includes an Inmarsat ship earth station, MF/HF DSC, VHF DSC, NAVTEX, an EPIRB, two SARTs and a reserve battery. The emergency generator supplies emergency lighting and the steering gear but does not supply the radio installation. The reserve battery is five years old. A capacity test last week, using a dummy load representing the GMDSS equipment, ended after 3 hours 25 minutes when the terminal voltage reached the manufacturer's end-point. The battery charger had a blown fuse and was bypassed with a portable charger for six weeks. The radio log shows no daily or weekly tests for the past ten days, and the MF/HF DSC watch receiver is tuned to 8414.5 kHz but the printer has no paper. The master says the ship is 'A3, so Inmarsat is the main system' and asks whether the vessel can sail for a 14-day voyage. A port State control officer is on board.
1. Determine the required reserve-source capacity for this ship and assess the 3 h 25 min test result against SOLAS Chapter IV.
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The reserve source of energy must be able to operate the GMDSS equipment required for the sea area for the period specified by SOLAS Chapter IV. The shorter one-hour allowance applies only where the emergency source of energy supplies the radio installation. Here the emergency generator supplies emergency lighting and steering gear but not the radio installation, so the reserve battery must support the radio equipment for at least six hours.
The measured 3 hours 25 minutes is therefore well short of the requirement. The deficiency is not excused by the fact that Inmarsat is carried: the reserve source must support the GMDSS installation, not just one preferred system. The history also matters. A battery that was bypassed to a portable charger for six weeks may not have been correctly charged, and a five-year-old battery that fails a capacity test should be replaced rather than merely recharged and retested. The capacity test should be repeated after correction using the specified load and end-point.
2. What immediate operational restrictions and corrective actions should be imposed, and what testing should be done before the ship sails?
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The ship should not sail on the basis of a reserve battery that has failed its capacity test. The charger circuit should be restored to its approved configuration, the battery should be replaced or proven capable of the full six-hour duty, and the capacity test should be repeated with a load representing the GMDSS equipment. The MF/HF DSC watch receiver should be restored to normal printing, and the missing daily and weekly tests should be carried out and logged.
If a replacement battery cannot be obtained before the planned departure, the master should seek flag-State direction. A dispensation, if granted at all, would need to be based on a realistic assessment of the voyage, additional reserve capacity or shore support, and a restriction that keeps the ship within a defined operating area. A promise to repair at sea is not adequate. The port State control officer should record the failed capacity test, the bypassed charger and the incomplete watchkeeping records as separate deficiencies, because they show weaknesses in different parts of the GMDSS maintenance regime.
3. What entries should appear in the radio log, and why are they part of the compliance evidence?
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The radio log should show the daily and weekly tests required for the equipment carried, battery voltage and charger status, the date and result of the capacity test, the charger defect and temporary bypass, the DSC watchkeeping arrangements, and the corrective action taken. It should also record the loss of the MF/HF printer and its restoration.
These entries matter because GMDSS compliance is not proved only by the presence of equipment. It is proved by a working reserve source, maintained watches and a maintenance history that would reveal degradation before a total failure. Missing entries for ten days weaken the ship's ability to show that the installation was continuously available. The log should be completed contemporaneously and reviewed by a responsible officer, not reconstructed after the inspection.