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How Does a Hydrostatic Release Unit Work?
Hydrostatic Release Units: Automatic Liferaft & EPIRB Safety for SOLAS Vessels
A Hydrostatic Release Unit (HRU) is a critical safety mechanism designed to automatically release life rafts or EPIRBs (emergency position-indicating radio beacons) when a vessel is sinking. This device operates using water pressure and is essential for SOLAS-regulated vessels.
When a ship sinks, the HRU is triggered at a depth between 1.5 and 4 metres, in compliance with SOLAS regulations. The water pressure activates a spring-loaded blade that cuts the rope or straps securing the liferaft, allowing it to float to the surface and automatically inflate. The liferaft is designed with a weak link that breaks under the force of buoyancy, ensuring it detaches from the sinking vessel.
HRUs are typically disposable and require no maintenance, but regular checks for expiry dates and proper attachment are recommended. Choosing the right HRU depends on the size of the liferaft and the type of vessel. While it’s optional for small boats, it is mandatory for all liferafts on SOLAS-regulated vessels to have an HRU to ensure automatic deployment in an emergency.
How Does a Hydrostatic Release Unit Work?
An HRU (Hydrostatic Release Unit) operates by using water pressure to automatically deploy safety equipment like liferafts or EPIRBs (Emergency Position-Indicating Radio Beacons) when a vessel sinks. As the vessel submerges, increasing water pressure acts on a diaphragm within the HRU's sealed casing. This pressure pushes the diaphragm inward, causing a pin, held under tension by a spring-loaded blade, to disengage. Once the pin is released, the blade springs forward and cuts through the strong rope or safety straps that secure the liferaft.
As the liferaft floats upward, the painter line becomes tight, firm or stretched—triggering the liferaft to inflate.
The additional buoyancy from the inflated liferaft increases tension on the painter line, causing a breakaway point, fully releasing the liferaft from the ship, allowing it to reach the surface. This process ensures that the safety equipment is deployed exactly when needed during an emergency at sea.
Are There Different Types of HRUs?
There are different types of Hydrostatic Release Units (HRUs), each designed to suit a wide range safety requirements for life rafts, EPIRBs, and other essential maritime safety equipment. The choice of HRU depends on the specific application, vessel size, and regulatory standards like SOLAS. Some HRUs are single-use and disposable, while others are reusable with regular maintenance. Understanding the different types of HRUs ensures that your safety equipment is correctly deployed in an emergency, offering reliable automatic release when needed most.
What Are the Best Hydrostatic Release Units (HRUs) on the Market for Liferaft & EPIRB Safety?
We offer a wide selection of high-quality Hydrostatic Release Units (HRUs) tailored to meet your liferaft and EPIRB release solutions needs. Their range includes trusted models like the long-lasting T-ISS Seamate, HAMMAR H20, and Jotron, all engineered to perform reliably even under extreme conditions. These HRUs are fully compliant with SOLAS, MED, MCA, USCG, and Bureau Veritas standards, ensuring that your safety equipment adheres to the most stringent and evolving maritime regulations. Whether you need EPIRB HRUs or Green Small Raft HRUs, I.C. Brindle & Co Ltd provides innovative designs, including automatic EPIRB releases, for safe and straightforward operation.
Seamate Ve-1HRU (3-year Expiry Life!)
The T-ISS SeaMate Ve-1 stands out as a versatile, cost-effective Hydrostatic Release Unit (HRU) designed for reliable performance in extreme conditions, from intense heat to polar environments. This HRU automatically releases life rafts and EPIRBs at a certain water level (usually a depth between 1,5 and 4 metres), when a vessel sinks, ensuring critical safety measures are activated promptly.
One of the key benefits of the SeaMate Ve-1 is its 3-year expiry life, which is longer than the usual 2 years of other HRUs. This means it lasts longer, saves money, and is better for the environment. It’s also compatible with remote release systems, allowing life rafts to be deployed from a distance if necessary.
The SeaMate Ve-1 has been tested and approved by major safety authorities like the US Coast Guard and the UK MCA. It also comes with an EPIRB model that includes all the parts needed for secure attachment, making it a great choice for both small boats and large vessels that need to meet strict safety standards. It also carries the Red Ensign UK conformity mark for marine equipment, indicating its approval for use on UK vessels and adherence to the stringent safety regulations set by the UK MCA.
This HRU is available in an EPIRB model, complete with the necessary bolt and nut for secure attachment, making it a reliable solution whether you’re outfitting a small boat or a SOLAS-regulated vessel. The SeaMate Ve-1 is tough, adaptable, and meets strict maritime safety standards for different conditions.
Hammar H20 HRU - HR-0100
The Hammar H20 is a reliable, SOLAS approved Hydrostatic Release Unit (HRU) designed to work in all kinds of extreme weather, from extreme heat to freezing cold. If a ship sinks, the Hammar H20 automatically releases life rafts and EPIRBs when the water pressure reaches a certain level.
The Hammar H20 is the best-selling HRU in the world, with over 25 years of successful use. It’s made from glass-fibre reinforced nylon, which doesn’t rust and doesn’t need annual maintenance or spare parts. You only need to replace it every two years, and the old unit is 97% recyclable, making it cost-effective and eco-friendly.
This HRU is easy to install and use, which helps keep storage costs low and reduces downtime. It can also be used with Hammar’s Remote Release Systems, allowing you to deploy life rafts from the bridge or other key locations on the ship, saving valuable time in emergencies.
Hammar H20 HRU EPIRB - HE-0100
For those needing an EPIRB version, the Hammar H20 EPIRB ensures the beacon activates automatically and starts sending signals when the vessel sinks. This makes rescue operations quicker and more effective. The Hammar H20 is reliable, durable, and easy to use, making it an excellent choice for maritime safety.
The Hammar H20 HRU is also available for EPIRBs, offering reliable auto-activation for emergency situations. When a vessel sinks, the Hammar H20 automatically releases the EPIRB when the water pressure reaches the right level, usually between 1.5 and 4 metres. Once the EPIRB reaches the surface, it starts sending out a signal to a satellite, helping rescue teams locate the vessel quickly.
Hammar H20 for Small Rafts - HR-0200
The Hammar H20 Small Raft model (HR-0200) is made for liferafts that hold fewer than 6 people and recreational rafts for up to 12 people, which are not covered by SOLAS regulations. For liferafts smaller than 4 people, contact us or the liferaft manufacturer for the right HRU.
This HRU has a white rope, a release mechanism, and a Red Weak Link with a green thimble. When the ship sinks, the water pressure will cut the rope with a sharp knife within about 4 meters. This lets the liferaft float free and start inflating as the ship sinks further. The Red Weak Link then breaks, allowing people to board the liferaft.
The Hammar H20 Small Raft HRU does not need annual servicing or spare parts but should be replaced every two years. It is approved by the USCG (approval number 160.062/14/10), ensuring it is reliable and meets safety standards.
Jotron Hydrostatic Release Unit for EPIRBs - 86218
The Jotron Hydrostatic Release Unit is designed for use with Jotron EPIRBs, such as the Tron 40AIS. It simplifies procurement by being compatible with a range of Jotron EPIRBs.
The Hammar H20 HRU automatically activates EPIRBs during emergencies. Trusted by many EPIRB manufacturers, this hydrostatic release unit EPIRB uses water pressure to release a securing bolt with a spring-loaded blade, allowing the EPIRB to float and send distress signals. Features include easy installation, rust-resistant construction, and no need for annual servicing. The HRU is 97% recyclable and approved by global safety standards.
See Our Hydrostastic Release Unit Range
Selecting the right Hydrostatic Release Unit (HRU) is vital for ensuring the safety and compliance of your vessel. Whether you choose the durable T-ISS SeaMate Ve-1 or the globally trusted Hammar H20, each HRU offers reliable automatic deployment of liferafts and EPIRBs, designed to meet your specific safety requirements and comply with current regulations.
Regular checks and proper maintenance are essential to keep these critical devices functioning effectively. To explore our full range of HRUs and find the perfect solution for your vessel, visit I.C. Brindle & Co Ltd. Our comprehensive selection ensures that you have access to the highest quality safety equipment, meeting all regulatory standards and providing peace of mind on the water.
