Industries

Gunnebo Industries’ Mooring Bolt – T-bolt No 8252 is made from high-tensile steel with excellent tensile strength and further reinforced through quenching and tempering, enabling it to withstand the strong forces of currents and waves.

The surface is hot-dip galvanized to prevent corrosion, ensuring long-term, reliable use. The standard model is a T-bolt, but custom orders for eye bolts are also available.

The newest model Mooring Bolt – T-bolt No 8257 has a permanent depth indicator incorporated making ROV installations en assembly easier and safer.

Mooring Bolt – T-bolt No 8257

Products Used:

Mooring Bolt - T-bolt No 8252

Mooring Bolt - T-bolt No 8257

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Gunnebo Industries’ Mooring Bolt with Swivel is a new-generation design that combines a swivel mechanism capable of 360° horizontal rotation with a shackle that moves 180° vertically.

This allows the bolt to automatically align with the load direction, ensuring consistently stable mooring.

In addition, a collar is placed beneath the swivel mechanism to secure it into the seabed rock, preventing the swivel from being crushed or seizing up, and enabling long-term, reliable use.

Products Used:

Mooring bolt with swivel

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In aquaculture, multiple cages are typically arranged in rectangular formations of 2×3 or 2×4 (or other combinations) and aligned against waves and currents. This setup ensures efficient oxygen supply, supports fish growth, and helps reduce costs.

At the core of this cage system is the Connection Plate, which links the cages together at key points—shown as red dots in the diagram. However, since it is positioned near the sea surface, the plate is highly exposed to corrosion, which is further accelerated by marine algae.

Gunnebo Industries’ Connection Plate is hot-dip galvanized to protect the inner metal from corrosion. In addition, it incorporates zinc-coated bolts known as sacrificial anodes, which are designed to corrode before the plate itself. This dual protection system ensures the plate remains stable and reliable for long-term use in demanding marine environments.

Products Used:

TXCP connection plate (Seastar)

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The Connection Plate is typically attached to a buoy to indicate its position. Since the buoy moves up and down constantly with the waves, the plate is subjected to repeated loading. Inexpensive products may not resist fatigue loading and show signs of wear and deformation.

Gunnebo Industries’ Connection Plate is designed to withstand the heavy impact loads caused by waves and storms, exceeding the strict requirements of Norwegian mooring equipment standards.

Furthermore, only products that pass rigorous in-house cycle testing are supplied, ensuring reliable safety at aquaculture sites.The lifting lugs on the connection plate are fatigue tested.

 Gunnebo’s connection plates come in two shapes: Round and a sea-star shaped plate.

Products Used:

TXCP connection plate (Seastar)

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When the seabed consists of sand rather than rock, anchors are installed instead of mooring bolts to secure fish cages. To verify that the anchor has been properly set, tension can be measured using Crosby Straightpoint’s Radiolink Plus. Its powerful wireless connection enables safe and accurate monitoring from a distance.

Selecting the right load cell for the environment is also essential. For applications above water, the Radiolink Plus is recommended, while for subsea use, the Subsea Link is the ideal choice. Built with a stainless-steel IP68-rated body, the Subsea Link withstands seawater, temperature fluctuations, and water pressure at depths of up to 2,000 m (6,562 ft), while providing precise tension measurement.

Products Used:

Crosby Straightpoint Radiolink Plus (RLP)

Crosby Straightpoint SubseaLink

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Damage to mooring equipment can result not only in significant losses from cage drift and escaped farmed fish, but also in brand reputation damage, legal risks, and dangers to workers and nearby vessels.

Crosby Straightpoint Cabled Load Shackle has a capacity of up to 3,000t and is rated to IP67 / NEMA6 environmental protection, making it suitable for use even in harsh marine conditions. It enables real-time monitoring of loads on mooring equipment, allowing early detection of abnormalities. By basing inspections and replacements on actual load data, it helps prevent accidents, reduce costs, and extend the service life of assets.

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Mooring chains use their own weight to provide slack in the mooring line, softening the impact of waves and currents. They are more durable than ropes, making them suitable for use near the water’s surface where contact with other components or vessels is likely, and helping extend the overall system life.

Gunnebo Industries’ Mooring Chain ensures a uniform coating thickness through a unique process in which each link is passed individually through a hot-dip galvanizing bath. Load testing is carried out before heat treatment to minimize residual stress and prevent breakage caused by stress corrosion cracking.

During use, the surface changes from shiny silver to gray. This indicates the formation of a protective zinc patina layer, which blocks water penetration and further enhances corrosion resistance.

With superior durability and corrosion protection, it is the ideal chain for mooring systems.

Products Used:

Gunnebo Industries Long Link Chain LLZ, Grade 6

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The Bridle for Aquaculture consists of a master link, a connecting link, and chain, all hot-dip galvanized for corrosion protection. Gunnebo Industries has obtained Norwegian NS certification and undergoes audits every two years.

Traditional designs had complex welding processes that limited production efficiency. To overcome this, Gunnebo introduced the press-on shackle (countersunk shackle), featuring a special bolt that must be deformed to lock in place. This robust design improves assembly efficiency and ensures a stable supply.

Since its launch in 2015, the new bridle has been used in marine environments for long periods without any quality issues, earning strong recognition at aquaculture sites. It can also be fitted to buoys, making it especially effective where chain length varies.

Products Used:

Bridle for Aquaculture

Galvanized Master Link

Aquaculture sling with oversize link

Countersunk Dee Shackle No A0830

Gunnebo Industries Long Link Chain LLZ, Grade 6

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Gunnebo Industries’ Mooring Shackle is used to secure cages via mooring ropes or to connect multiple lines through a connection plate.

Compared to standard lifting shackles, the bow section is designed 25% thicker, enhancing strength and service life. The wider bow also makes it suitable for larger thimbles, ropes, and chains.

Both the body and the bolt are hot-dip galvanized, with an additional coating applied to the bolt for superior corrosion resistance. The hexagonal sunken bolt fits securely into the bow groove to prevent rotation, allowing easy and reliable tightening with just a spanner.

In addition, a Grade 8 full nut is used instead of a half nut to prevent loosening. Performance in low-temperature impact and fatigue tests has exceeded industry standards and far outperformed lower-cost alternatives.

This shackle combines durability, wear resistance, and corrosion resistance, making it an ideal choice for mooring systems.

Products Used:

Mooring Shackle No 852

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The Master Link is the central ring that gathers bridle chains or ropes and connects them to the connection plate or other mooring lines. As a critical junction that distributes forces, it requires high fatigue strength, durability, and corrosion resistance.

Gunnebo Industries’ Galvanized Master Link has demonstrated performance far exceeding Norwegian NS standards in fatigue testing, and it also passed both EN and NS standards in strength testing. In addition, it successfully passed stress corrosion cracking tests without any issues, proving its reliability for safe use even in harsh marine environments.

Master link : According to EN 1677 (and NS9415)- the weld should bend 0,8 x diameter without any signs of cracks ; however, NS9419 requires a 1,5 x diameter bend without cracks.

• Gunnebo links meet the requirements of NS 9419 , meeting higher standards then required by NS9415

Products Used:

Galvanized Master Link

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Mooring ropes connect seabed anchor bolts or anchors to surface buoys and cages, while also absorbing and dispersing the impact of waves and currents.

The Thimble protects the rope’s eye splice, preventing abrasion, extending rope life, and reinforcing the splice with metal for added safety.

Kito Crosby Thimbles are available in open and closed types, as well as tube type and semi-tube type, which fully or partially encase the rope eye in metal. All products are hot-dip galvanized, providing excellent resistance to both wear and corrosion.

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Thimbles

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