Test of EPIRB and its Hydrostatic Release Unit (HRU)

Learn how the hydrostatic release unit works to automatically release (by water pressure) and start (by water contact) a float-free EPRIB

”The hydrostatic release unit is an essential piece of equipment for any sailor operating at sea,” our customer Leon explains. – The HAMMAR H20E HRU has a knife inside which cuts the bolt, allowing the spring to pop up and the EPIRB to float free up to the surface. This is extremely important if you find no time to get your EPIRB, e.g. in case of a collision at sea or an immediate or sudden capsizing. 

“This is how you test the hydrostatic release unit in water,” he continues. – It says release depths 1.5 to 4 meters so when the EPIRB goes down 1.5 to 4 meters, the knife should be released, cutting the bolt and releasing the EPIRB. It is hydro static; meaning it should be released by the water pressure. Look – the bolt is cut, the EPIRB releases, goes up to the surface and sends a distress message after the ship has gone down.

See the video: This is how the EPIRB and its Hydrostatic Release Unit works

“The HAMMAR H20E hydrostatic release unit must be changed every 2 years. It has a bolt – and you must buy this original from Jotron! They are the only ones who supply this plastic bolt. Don’t ever use another type of bolt because it needs to be weak enough to be cut through by means of this spring,” Leon emphasizes.

A superuser of Jotron maritime emergency devices

Leon has extensive experience and knowledge of the company’s product portfolio: “When I bought my first Jotron device, I was some 20 years old. It was a strobe light and I thought it was really cool. 40 years later it’s still working well. Since then, I’ve had loads of emergency signaling devices from Jotron. Before the AIS-SART, I had a radar SART search and rescue transponder – and of course; EPIRBs. When you are sailing outside the GMDSS area A1 you really must be aware that your VHF coverage is not so far as you might think. So as soon as you sail over the North Sea and outside the A1 area, you need another type of emergency signaling device – and an EPIRB it’s really something good.”

Map showing A1 area for GMDSS coverage

Facts: EPIRB testing

You should test your EPIRB according to the product manual since the recommended EPIRB testing might be different from type to type and between different brands. Depending on type of EPIRB, the EPIRB battery must be change according to the product manual, or according to mandatory requirements, or according to the flag administration. Jotron recommend a thorough investigation of the EPIRB’s float-free bracket after 10 years to be sure the plastic is optimal after use in harsh maritime environments.

Facts: Float-free EPIRB Hydrostatic Release Unit (HRU)

The HAMMAR H20E hydrostatic release unit releases the float-free EPIRB when the ship sinks. A spring activated knife cuts the release rod at a water depth of 1.5 to 4 meters, allowing the EPIRB to float free. The expiry date of the HRU is 2 years after installation. This must be marked in the field when being installed on board.