Purpose-Designed Hoists for Underwater Operation

Posted by Eric Haun
Friday, August 08, 2014
Typical poor visual conditions for aquanaut utilizing a JDN subsea hoist.

Lifting and handling products manufactured by the J D Neuhaus company are engineered for performance, reliability and longevity when operating in extreme environments of dirt, dust, high humidity, and even potentially explosive atmospheres. Some of the toughest and more unusual conditions are currently experienced by today’s underwater aquanauts. Divers are very often working alone, in conditions of variable depth water pressures and temperatures, combined with poor visibility while also battling with ocean currents. With all these problems to contend with, any tools they use need to be rugged, reliable, easy to operate and comply with the highest performance standards.

The last few decades has seen unparalleled development in the field of oil and gas exploration, particularly offshore. JDN hoists have played their part in this market, offering hoists with lift capacities from 550lbs up to 100 metric tons, with specialized units of 200 metric tons lift capacity having been supplied for BOP handling. The development of subsea hoists means that underwater as well as on-deck lifting operations for a wide range of operational, maintenance and repair functions can be undertaken on jack-up rigs, semi-submersible platforms, drill ships and FPSO vessels. Even undertaking underwater pipeline and wellhead operations down to levels of 70 meters can also be considered.

The proliferation of offshore wind farms and wave powered generation systems has also increased the potential requirements for suitable power tools that can be safely utilized underwater. Harbor locations often require underwater work, albeit not at great depths, while lakes, rivers, dams, reservoirs and bridge building operations can also have need for similar inspection, recovery or repair operations.

The viability of JDN hoists in the underwater environment has been demonstrated when their air operated hoists were successfully utilized for the removal and replacement of a 50 ton rudder on a fully loaded bulk carrier vessel. After breakdown during a voyage from Brazil to China, the ship was first towed to a safe mooring off the coast of Venezuela, where the rudder removal and replacement work was undertaken. Three standard air operated JDN Profi 25 metric ton capacity hoists were used in conjunction for this operation, with these units being subject to full rebuild procedures after the job completion. The work was successfully undertaken at sea, without the need for cargo removal or transfer.

Subsequent to this exercise, the JDN company have introduced purpose designed hoists suitable for subsea operation, incorporating uprated performance and sealing features to withstand continuous underwater operation, even at depths of 70 meters. They can be supplied for either compressed air or hydraulic operation, utilizing a diver-friendly pendant controller which is compatible with constricted, gloved-hand movements.

This controller is connected by standard length 2 meter hoses to the hoist which ensures the aquanaut, hoist and load are all located within a close working environment. It is designed to ensure instantaneous and sensitive regulation of the hoist movements, providing infinitely variable speed of the load hook during both the raise and lower hoist operations. The need for voice instructions to/from a surface vessel or rig is obviated, eliminating potential delays or errors created through poor communications. Increased versatility is also provided by the fact that these hook-suspended hoists can also be safely utilized for both horizontal and oblique pulling operations when required. Overload protection is incorporated as standard to cover whatever type of underwater work is undertaken within the demanding inner space environment.

The hoist lift chains provide a 3 meter raise/lower capacity as standard for variable load options of up to 3.2 or 6.4 metric tons respectively. Variations on the length of lift chains or hose feeds to the pendant controller can also be changed for greater versatility. Hoists designed for higher or lower load limits, together with products capable of operating at depths greater than 70 meters could also be manufactured if required.

The hoist construction utilizes stainless steel for smaller exposed nuts and bolts together with valve heads, with grease packed covers fitted for larger fixings and wheel bearings. The remaining exposed metalwork is finished with three layers of traffic yellow RAL 1023 marine protective paint to a 300 micron dry thickness, as normally designated for offshore, salt laden operations. These purpose designed hoists can now successfully accommodate heavy duty, high performance operations with minimum maintenance or lubrication over extended periods of subsea operation. The fact that the hoist, diver operator and workpiece being manipulated are all retained within a regulated, visual distance ensures that maximum control and safety is maintained during difficult handling procedures.

jdngroup.com
 

  • J D Neuhaus Profi 6 TI hoist, purpose designed for subsea operation.

    J D Neuhaus Profi 6 TI hoist, purpose designed for subsea operation.

  • A J D Neuhaus Profi 6TI subsea hoist equipped with ‘diver friendly’ controls

    A J D Neuhaus Profi 6TI subsea hoist equipped with ‘diver friendly’ controls

Maritime Today


The Maritime Industry's original and most viewed E-News Service

Maritime Reporter July 2016 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

New Products

Update to FORAN Lets Users Manage Series of Ships

SENER has launched an update of its FORAN shipbuilding CAD/CAM/CAE system.   Version V80R1.0, which was launched onto the market when FORAN celebrated its 50th anniversary in 2015,

CMA CGM Adds Weekly India Port Calls

CMA CGM Group announced the launch of two new weekly services, EPIC 1 and EPIC 2, between the Arab Gulf, Pakistan, North West India and North Europe. The current

SOLAS VGM: Concerns, Impacts and the Road to Compliance

Shipping industry veteran Dan Gardner is director of Mobileweight, which helps to streamline processes and create efficiencies for the container shipping industry.

Offshore

MOL Signs Long-Term Charter with Uruguayan JV for FSRU

Japanese shipping company Mitsui O.S.K. Lines, has, through its wholly-owned subsidiary Lakler S.A., agreed to conclude a charter contract with Gas Sayago, for

Migrants Survivors Tell of Struggle at Sea

The bodies of 21 women and one man were brought ashore to Sicily on Friday as fellow migrants described scenes of panic and violence when water poured into their dinghy.

Three Keppel Dredgers for Jan De Nul

Keppel Offshore & Marine Ltd (Keppel O&M)'s wholly owned subsidiary Keppel Singmarine Pte Ltd (Keppel Singmarine) has secured contracts from Jan De Nul Group to

Marine Equipment

NASSCO Bags USS Oak Hill Modification Award

General Dynamics NASSCO-Norfolk was awarded a $42 million cost-plus-award-fee modification to a previously awarded contract for the repair and alteration for the USS Oak Hill (LSD-51).

Thyssenkrupp Involves in Panama Canal Expansion

Thyssenkrupp supplied 14 innovative elevators for expansion of the Panama Canal , seven for each new lock complex, one of which is on the Atlantic side and the other on the Pacific.

US Navy Tests Latest Aegis Weapon System

The U.S. Navy conducted a series of cooperative air defense test exercises with the Spanish navy that culminated in live missile firing events using the latest Aegis Weapon System baseline July 20-21.

Underwater Engineering

Pathogenic bacteria hitchhiking to North and Baltic Seas?

For the first time, AWI scientists have found evidence of living, potentially pathogenic vibrions on microplastic particles. With increasing water temperatures

Ithaca’s FPF-1 platform to be moved to Stella field

Ithaca Energy Inc. reports that the "FPF-1" floating production facility has completed the required inclination test as planned and departed the Remontowa shipyard in Gdansk, Poland.

Great Lakes Dredging Awards Announced

Great Lakes Dredge & Dock Corporation announced that it was recently awarded four contracts with an approximate value of $93 million. Great Lakes received two

 
 
Maritime Careers / Shipboard Positions Maritime Contracts Maritime Security Naval Architecture Navigation Offshore Oil Pipelines Ship Electronics Ship Repair Winch
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: 0.1301 sec (8 req/sec)