Lankofirst Trials New Fiber Rope Connectors

MarineLink.com
Tuesday, May 21, 2013
Lankofirst fiber rope connector offshore trial

Lankofirst said offshore trials of its synthetic fiber rope mooring connector have shown a reduction in mooring line deployment times and improvements in health and safety compared with traditional mooring line plate links and thimbles, reports deepwater mooring rope specialist, Lankhorst Ropes Offshore Division (LROD).

The cost and complexity of deploying deepwater moorings is driving the development of new mooring line technologies and deployment methodologies. Lankhorst, in collaboration with LROD worldwide agent, Offspring International and subsea mooring connector specialist First Subsea, has developed the Lankofirst fiber rope connector specifically for deepwater fiber connections.  Smaller, lighter, stronger and more efficient than current plate links and thimbles, the Lankofirst is easier to make-up and the rope splice slimmer and lighter for the same MBL.  The Lankofirst can be used for all fiber rope mooring connections including rope-rope, rope-wire and rope-chain connectors.

The recent trial offshore Norway has shown that the Lankofirst connector can be assembled in 15 minutes, compared with at least 1 hour 15 minutes for a traditional shackle. In addition only two people are needed to assemble the connector, unlike a shackle which usually requires three people, requiring fewer people on deck during hazardous line make-up operations.

The Lankofirst fiber rope connector is made from forged steel using First Subsea's research into optimal steel grades for long-term deepwater subsea mooring connectors. The company was the first manufacturer of offshore mooring connectors to achieve American Bureau of Shipping's ABS 2009 Approval for specialist subsea mooring connectors covering the design and manufacture of large scale forgings over 500mm in diameter.

In place of a large spliced soft eye normally used with H-link and shackle connections, the Lankofirst uses a sub-connector Donut which is integrated into the rope termination during manufacture. The innovative and smaller donut splice is much easier to handle offshore.

For maximum installation flexibility, the Lankofirst is offered with clam, snap and link connections. The offshore trials used the clam design, and the snap and link are in development. The connection is made by inserting the two rope sub-connectors into the open clam, and then bolting the clam shut. This contrasts with the assembly of the shackle connection which involved inserting the shackle into the splice eye and then hammering in the large diameter retaining bolt.

In addition to developing the Lankofirst fiber rope connectors, Lankhorst Ropes and Offspring International have also identified improvements in deployment methodologies to reduce the  time, complexity and cost of installing deepwater mooring systems.

During mooring installation or hookup operations, the mooring line is preloaded to induce permanent elongation in the rope (sometimes called construction stretch or bedding-in) and increase its stiffness. Once all the mooring lines are connected they are pre-tensioned.  Traditional approaches to preloading synthetic rope mooring lines have been based on 40% MBS (Minimum Breaking Strength).

Given industry concerns about the rising cost of performing deepwater installations, and mooring ropes with MBSs rising to over 2,500T, a new methodology to both rope pre-loading and pre-tensioning has been developed to reduce the high cost and safety issues surrounding excessive pre-loading. The traditional approach to preloading is based on rope testing at fixed loads and variable length.

A better method is to use fixed length ropes that are preloaded to 30%, and subsequent storms providing the final line tensioning to 40%. This approach to mooring system deployment enables significant reduction in the size of installation vessels, and time needed to deploy moorings. It is also better suited to the practicalities of deploying stronger synthetic mooring lines needed for ultra-deepwater moorings, which will be beyond the scope of existing installation vessels.

Recently the concept of lower pre-loading has being taken a stage further by considering the case of a FPSO mooring. In this instance, pre-tensioning is proposed without the need for installation vessels, other than for deployment and hook up, relying instead on deballasting and ballasting the vessel to provide the pre-tensioning needed to install the mooring lines.

"The lower pre-loading approach is consistent with the viscoelastic nature of synthetic ropes. All we are doing is using the fiber's ability to recover its original length after the 40% storm loading to complete the final installation," said Dave Rowley, director, Offspring International Ltd.

www.lankhorstropes.com
 

  • Lankofirst fiber rope connector on mooring line winch

    Lankofirst fiber rope connector on mooring line winch

Maritime Reporter May 2015 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

New Products

Baltic Mercur II makes maiden voyage to Antwerp

This week Atlantic Ro-Ro Carriers (ARRC) celebrates the maiden voyage of the Baltic Mercur II via the port of Antwerp as part of their regular transatlantic service to the US Gulf.

Alaska, Washington to build Arctic Icebreakers

Senator Lisa Murkowski, Alaska, and Senator Maria Cantwell, Washington, have introduced a bill that would authorize the Navy to build up six icebreakers for use by the U.

DMW Marine Takes the Lead in Military Cranes

DMW Marine Group, LLC. has completed a number of projects for the U.S. Navy and foreign Navies in recent years, claiming a place as a go-to supplier for Navy departments globally.

Offshore

EIVA Welcomes New Global Director

The Danish offshore survey solution specialist EIVA a/s has appointed a new global sales director, Jakob Møller Nielsen. He comes from a similar position at SPX Flow Technology,

ASRY in Maritime Deal with Relay

UK-based engineering firm signs service agreement to provide direct services to vessels in ASRY, expanding the list of the yard’s onsite specialist contractors.

Harnessing Offshore Wind Peaks in U.S.

For the US energy industry, 2014 will be remembered as the year when crude oil prices fell below 50$/bbl, resulting in significant realignments in the sector.

Marine Equipment

ASRY in Maritime Deal with Relay

UK-based engineering firm signs service agreement to provide direct services to vessels in ASRY, expanding the list of the yard’s onsite specialist contractors.

DNV GL’s Synergi to Manage Siem Offshore Newbuilding Projects

Siem Offshore has chosen DNV GL’s Synergi Project to manage nine newbuilding projects. Synergi Project software The software is used to optimize the collaboration

USS George Washington Completes Carrier Qualifications

Carrier Air Wing (CVW) 5 and the Nimitz-class aircraft carrier USS George Washington (CVN 73) completed its carrier qualifications (CQ), May 23. CQ allows

 
 
Maritime Contracts Maritime Security Naval Architecture Navigation Offshore Oil Pipelines Pod Propulsion Ship Electronics Ship Repair Shipbuilding / Vessel Construction
rss | archive | history | articles | privacy | contributors | top maritime news | about us | copyright | maritime magazines
maritime security news | shipbuilding news | maritime industry | shipping news | maritime reporting | workboats news | ship design | maritime business

Time taken: 0.2493 sec (4 req/sec)