Emergency batteries as well as GMDSS batteries onboard serve an important function. During a black out, emergency generator need some power source to start automatically.
Emergency batteries acts as the source for thi required power to the emergency generator. If the emergency batteries are week, emergency generator may not start in auto mode.
We would then need to start the emergency generator manually from emergency generator room. This can take away vital time which may result in disastrous situations.
There are many ships where on load testing the emergency generator require black out of ESB.
If so, We should carry out this load test atleast every 3 months. The procedure to load test the emergency generator will be to disconnect ESB from main switchboard and then observing if emergency generator starts automatically.
If it doesn’t start, among other things we should also check the condition of batteries.
There are battery tests that the seafarer responsible for batteries must know. Regular testing of the emergency generator should also include tests to ensure if batteries can supply power to start emergency generator.
This goes for GMDSS batteries too. As per SOLAS GMDSS batteries should provide power to operate GMDSS for
- 1 hour in case GMDSS has the power from emergency generators
- 6 hours in case GMDSS does not have the power from emergency generators.
Now how do we test the GMDSS batteries to be sure that these won’t die down before the required time. Some of us confuse this test with the On load/Off load daily test of the batteries.
They argue that we need to switch off the AC power to GMDSS and operate the GMDSS for 1 hour (or 6 hours) . But this is not correct.
Yard provides the specifications of the required batteries during delivery of the vessel. If we have renewed the batteries with same specifications, we can be sure that the batteries would last for the required period.
Of course this would not be the case if the capacity of the batteries has reduced during the life of the batteries. To be sure that the capacity of the GMDSS batteries is OK, a capacity test is performed every year.
This is important test which ensures that in emergency your GMDSS batteries would last up to the required time.
Wishing you all fair winds following seas
About Capt Rajeev Jassal
Capt. Rajeev Jassal has sailed for over 19 years mainly on crude oil, product and chemical tankers. He holds MBA in shipping & Logistics degree from London. He has done extensive research on quantitatively measuring Safety culture onboard and safety climate ashore which he believes is the most important element for safer shipping.