Home / Artikel
The Hydrostatic Release Unit (HRU) Chiyang is an automatic maritime safety device designed to assist in the release of liferafts or EPIRBs when a vessel experiences an emergency, including when the ship sinks. This device operates by utilizing the hydrostatic pressure of seawater, allowing the liferaft to detach from its mounting and float to the surface automatically.
In vessel operations, safety devices such as the HRU play a critical role because evacuation processes cannot always be carried out manually. In conditions involving vessel listing, fire, flooding, severe weather, or rapid sinking, crew members may not have sufficient time to release the liferaft. Therefore, the use of the Chiyang Hydrostatic Release Unit serves as an essential solution to support maritime safety preparedness.
The Hydrostatic Release Unit or Chiyang HRU is an automatic release device installed on liferafts, liferaft racks, or safety equipment such as the Emergency Position Indicating Radio Beacon (EPIRB). The HRU operates based on changes in water pressure when the vessel sinks to a certain depth.
When water pressure reaches the activation level, the internal mechanism within the HRU engages to cut or release the liferaft's securing line. Once the liferaft detaches from its storage location, it can float to the water surface and inflate automatically through the gas inflation system available on the liferaft unit.
With this automatic mechanism, the Chiyang HRU helps ensure that safety equipment remains usable even if the crew does not have time to perform manual release.
The primary function of the Chiyang Hydrostatic Release Unit is to release the liferaft automatically when the vessel sinks. This device is an important part of the vessel's safety system as it can increase the likelihood that rescue equipment will be available during emergencies.
Several key functions of the Chiyang HRU include:
Automatically opening the liferaft securing system when the vessel sinks to a specific activation depth.
Assisting the liferaft in detaching from its cradle, rack, or storage mount.
Enabling the liferaft to float toward the water surface.
Supporting automatic liferaft inflation after the painter line is pulled according to the liferaft mechanism.
Assisting in the automatic release of EPIRBs so that distress signals can be transmitted when the vessel sinks.
Reducing reliance on manual release in fast-moving and high-risk emergency situations.
Supporting compliance with maritime safety equipment requirements on cargo ships, passenger vessels, workboats, fishing vessels, and various other types of fleets.
The Chiyang HRU operates using the principle of hydrostatic pressure or water pressure. When the vessel sinks, the water pressure around the device increases as the ship's depth below the sea surface increases.
At a depth of approximately 1.5 to 4.0 meters, water pressure activates the internal mechanism within the Hydrostatic Release Unit. This mechanism then moves an internal blade to cut the securing line holding the liferaft in place.
Once the securing line is cut, the liferaft becomes free from its cradle or storage rack and is pushed to float to the surface. Under normal conditions, the liferaft painter line remains secured to the vessel for a short period. When the liferaft floats and the painter line is pulled, the liferaft inflation system activates, causing the liferaft to inflate automatically.
Subsequently, when the pulling load reaches a certain limit, the weak link section breaks. This mechanism allows the inflated liferaft to detach from the sinking vessel and remain on the surface for use by crew members or passengers.
In simple terms, the working stages of the Chiyang HRU are as follows:
The vessel experiences sinking or water immersion conditions.
Water pressure increases when the HRU reaches the activation depth.
The Chiyang HRU activates at a depth of approximately 1.5 to 4.0 meters.
The internal blade cuts the liferaft securing line.
The liferaft detaches from its mount and floats to the surface.
The painter line is pulled, triggering liferaft inflation.
The weak link breaks at a certain load, allowing the liferaft to detach from the sinking vessel.
The HRU-1R Chiyang is designed as an automatic safety device for releasing liferafts and related safety equipment. Its specifications support a safe and controlled release system in accordance with maritime safety requirements.
The following are the main specifications of the Hydrostatic Release Unit HRU-1R Chiyang:
Release depth: 1.5 to 4.0 meters below the water surface.
Operating system: uses hydrostatic water pressure to activate the internal cutting mechanism.
Breaking strength of white sling line: minimum 15 kN.
Breaking strength of weak link: 2.2 ± 0.4 kN.
Weak link function: allows the inflated liferaft to detach from the vessel at a certain pulling load.
Applications: used on liferafts, EPIRBs, and maritime safety equipment requiring an automatic release system.
Safety standards: approved and compliant with SOLAS (Safety of Life at Sea) regulations.
Maritime safety is a primary aspect in the operation of every vessel. In addition to providing liferafts, life jackets, life buoys, EPIRBs, fire extinguishers, and other safety equipment, vessels must also ensure that these devices can be used effectively when emergencies occur.
A properly stored liferaft still carries the risk of being unusable if the vessel sinks too quickly and the crew does not have time to release it. In such conditions, the Chiyang HRU serves as an automatic backup system that can operate without human intervention.
HRU installation also helps vessel operators maintain better safety standards, particularly for vessels operating in open seas, inter-island waters, port areas, offshore regions, or shipping routes with high weather risks.
However, it is important to ensure that the HRU is installed correctly and inspected regularly. Devices that have exceeded their service life, experienced physical damage, been exposed to corrosion, or are incompatible with the liferaft configuration may reduce the effectiveness of the safety system.
The Chiyang Hydrostatic Release Unit can be a suitable choice to support vessel safety equipment readiness. Some advantages of using the Chiyang HRU include:
Operates automatically when the vessel sinks to the activation depth.
Helps release the liferaft without relying entirely on manual crew action.
Uses a simple and effective water pressure mechanism.
Features an internal blade system to cut the liferaft securing line.
Equipped with a white sling line with a minimum breaking strength of 15 kN.
Uses a weak link with a breaking strength of 2.2 ± 0.4 kN in accordance with safety regulations.
Complies with SOLAS regulations to support maritime safety standards.
Suitable for cargo ships, passenger vessels, workboats, offshore vessels, and various other maritime fleets.
To ensure the Hydrostatic Release Unit functions optimally when needed, vessel owners and safety officers must conduct regular inspections. The HRU is not merely a liferaft accessory but a critical component in the vessel's emergency safety system.
Several points to consider in maintaining the Chiyang HRU include:
Ensure HRU installation follows the installation instructions and liferaft configuration.
Regularly inspect the physical condition of the unit body, lines, slings, and weak link.
Ensure there are no cracks, excessive corrosion, deformation, or damage to securing components.
Pay attention to the HRU's expiration date or service period before use.
Replace the HRU according to the replacement schedule recommended by the manufacturer and vessel safety regulations.
Ensure the liferaft can be released manually if necessary.
Conduct regular inspections of the liferaft and its mounting system as part of vessel safety checks.
Use products and components that comply with the vessel's maritime safety equipment specifications.
If you need a Chiyang Hydrostatic Release Unit HRU for liferaft, EPIRB, or other vessel safety equipment needs, ALNINDO is ready to help provide maritime safety products for your vessel's operational requirements.
For orders and special pricing information, contact WhatsApp at 081586838888. You can also visit ALNINDO's official website at alnindo.com and alnindo.id.
ALNINDO office address:
Perkantoran, Jl. Taman Palem Mutiara No. 1 Blok A18, RT.7/RW.14, Cengkareng Timur, Kecamatan Cengkareng, Kota Jakarta Barat, Daerah Khusus Ibukota Jakarta 11730.
What is a Hydrostatic Release Unit or HRU?
A Hydrostatic Release Unit is an automatic safety device that uses water pressure to release liferafts or EPIRBs when the vessel sinks to a certain depth.
What is the main function of the Chiyang HRU?
The primary function of the Chiyang HRU is to automatically cut the liferaft securing line so that the liferaft can detach from its mount, float to the surface, and inflate according to the liferaft inflation system.
At what depth does the HRU-1R Chiyang operate?
The HRU-1R Chiyang is designed to activate at a depth of approximately 1.5 to 4.0 meters below the water surface.
How does the Chiyang HRU work?
The Chiyang HRU utilizes water pressure when the vessel sinks. When pressure reaches the activation level, the internal mechanism moves a blade to cut the liferaft securing line. The liferaft then detaches and floats to the surface.
What is the purpose of the weak link in the HRU system?
The weak link serves as a controlled breaking point. After the liferaft inflates and the vessel continues to sink, the weak link breaks at a certain load, allowing the liferaft to detach from the vessel and remain floating on the surface.
What is the breaking strength of the HRU-1R Chiyang weak link?
The weak link of the HRU-1R Chiyang has a breaking strength of approximately 2.2 ± 0.4 kN.
What is the breaking strength of the white sling line on the Chiyang HRU?
The white sling line on the Chiyang HRU has a minimum breaking strength of 15 kN.
Does the Chiyang HRU meet SOLAS standards?
The Chiyang HRU has been approved and complies with SOLAS (Safety of Life at Sea) regulations, making it suitable for supporting maritime safety requirements.
Does the Chiyang HRU need to be replaced periodically?
Yes. The HRU must be inspected and replaced according to its service life, manufacturer recommendations, and vessel safety inspection regulations. Periodic replacement is important to maintain device readiness during emergencies.
How do I order the Chiyang Hydrostatic Release Unit HRU?
To order the Chiyang HRU and obtain special pricing information, contact WhatsApp at 081586838888 or visit alnindo.com and alnindo.id.
