A trawler recently changed hands and a high level alarm conforming to the attached schematic was ordered to be fitted before the vessel sailed.
The new owner agreed and put the job in hand, but unfortunately the vessel sprang a leak whilst alongside the quay and flooded the engine room causing considerable damage before the installation was completed. The leak was caused by localised corrosion where pig iron ballast was in contact with the hull.
The strobe would have been noticed by harbour security that night had the yard electrician completed his job a little faster!
Flooding that goes undetected regularly leads to loss of the vessel with serious risk to life. The schematic below is referred to in the report and intended as a secondary alarm, directly wiring the ship’s batteries to a strobe on the wheelhouse deck-head via a float switch.
Simple and cheap for any size of vessel; below shaft level, high enough to test easily and less likely to generate annoying false alarms, but allowing adequate time to sort out most problems and always on; even in port.
It is a common sense solution, but also the law; the 15-24m Code states that ships must have either an independent secondary alarm or a “fail safe” primary system.