During an exercise with a man overboard boat (MOB boat) one of the crewmembers happened to pull the handle for releasing the hook (A in the picture). The boat fell 14 metres down to the surface of the water, hitting the davit on the way down and tipping out three of the crew into the water. All three were slightly injured.
A spring-loaded mechanism should prevent the release handle from being activated before the boat is launched (behind the cover marked as D in the picture). The pin in the hydrostat had corroded, however, and was stuck in the activated position. As the box with the pin inside cannot be opened, maintenance was not possible.
The Swedish Transport Agency recommends that all existing installations be looked over. The system is manufactured by Schat-Harding. Refer to more detailed information at the Swedish Transport Agency’s Safety Alert.
SFu ref 060502-TSS09-5348