Hydrostatic (Non!) Release Unit

Report Text:

Whilst travelling as a passenger on a vessel, I noted that the hydrostatic release unit (HRU) on a life-raft valise had been incorrectly fitted. In the event of the vessel sinking (albeit unlikely) the liferaft would probably have been pulled down with the ship. I sent a message to the company. They promptly thanked me for having advised them and advised that the non-conformance had been rectified. They also advised that the valise contained a Means of Rescue rather than a liferaft. I attach a photograph of the incorrectly fitted HRU.

CHIRP Comment:

The HRU had indeed been incorrectly rigged.  As shown in the photograph, the painter had been lead through the shackle connected to the webbing securing the valise. Therefore, if the HRU had been activated, the painter would have remained connected to the webbing strap and thus to the ship.

In contrast to the previous report, the reporter was given prompt confirmation that the issue had been addressed.

There is a general lesson that the HRU was visible to the ship’s staff but nobody had previously noticed that it was rigged incorrectly. It is useful for members of the ship’s safety team to carry out walk-around checks of the vessel so that such aberrations are spotted and corrected.

Marine Guidance Note (MGN) No. 362 issued by the Maritime and Coastguard Agency, regarding the servicing of liferafts etc., highlights that there have been incidences of incorrectly installed HRUs resulting in compromise of  the float-free arrangements of liferafts.

Diagrams showing the correct installation of various types of HRU can be found in MGN No. 343 on Hydrostatic Release Units – Stowage and Float Free Arrangements for Inflatable Liferafts.

Here is also a useful illustration from the safety training manual of a fishing company