If you can read the label on your liferaft hydrostatic release unit without standing on your head then it may be incorrectly installed, suggests a warning from Marine Safety Forum. Worth noting that the problem was identified onboard a vessel during an internal inspection only two days after a flag state safety equipment survey.
The discovery concerned Thanner 4 Year Hydrostatic Release Units which comprise a hydrostatic bolt within a frame. When the release operates, the bracket comes free of the bolt, allowing the raft to float free. At this point the painter should remain attached to the ship via a small wire weak link; the same would apply if the raft had been released manually. If the release unit has been fitted upside down, as has been found recently as shown below left, the weak link is not connected to the ship. Therefore, upon release, the raft would be allowed to float free without inflating, which could result in an evacuating crew having a very bad day.
Says the alert: “Further confusion may arise from the labelling on the units. Normally on our vessels the label is upside down when the units are correctly fitted, for example, if the label reads the right way up, the unit is the wrong way up. However, all vessels must be aware that this may be dependent upon how the unit was labelled at the manufacture, and therefore cannot be a trusted indication of being fitted correctly”.
If you have this type of HRU check that they are correctly rigged. Instructions are supplied with the units and should be inserted in the ship’s SOLAS manual; copies of the instructions should also be posted near the life rafts.