NEW Mooring Line Cable Fairing

NEW Mooring Line Cable Fairing

Introduction

DeepWater Buoyancy, Inc. has added a new product to their successful line of Mooring Line Cable Fairings.  The new fairing is designed to accommodate 1/4″ jacketed wire rope.  It is the latest item in the company’s portfolio of products for subsea mooring systems.

Vortex-induced Vibration

Under certain flow conditions, taut mooring lines can vibrate or “strum”. The strumming is caused by vortices that result from the water passing over the line diameter. Strumming not only creates cable fatigue, it can have a detrimental effect on instruments in the mooring string.

Mooring Line Cable Fairing

DeepWater Buoyancy’s mooring line cable fairings reduce strumming by eliminating this vortex action.  Less strumming means less fatigue on the line. Additionally, the fairing design reduces drag on the mooring line resulting in less mooring layover. As an example, the drag coefficient for a 3/8” jacketed wire cable is 1.20, whereas the mooring line fairing is 0.17. This is an improvement of over 85%.

Fairings are made of durable ABS plastic. They are easily loaded onto the mooring line during deployment simply by separating the ends of the fins and installing over the line.

Unlike other solutions, this product can be installed over select portions of the line, requires no maintenance, does not suffer from tangling problems, and resists biofouling.

The standard units are designed for 1/4″ and 3/8″ jacketed wire rope and are 12” in length. Other diameters and lengths can be produced upon request. End clamps are also available to limit the vertical movement of the fairing on the line.

Learn More

Learn more about mooring line cable fairings HERE

Download a datasheet HERE

See all our product types HERE

About DeepWater Buoyancy, Inc.

DeepWater Buoyancy creates subsea buoyancy products for leading companies in the oceanographic, seismic, survey, military and offshore oil & gas markets.   Customers have relied on our products for over thirty-five years, from the ocean surface to depths exceeding six thousand meters.

For further sales information:  Dan Cote, Sales Manager  |  sales@deepwb.com  |  +1 207 502 1400

For further company information:  David A. Capotosto |  davidcap@deepwb.com  |  +1 207 468 8545

DeepWater Buoyancy in MTR100

DeepWater Buoyancy in MTR100

Announcement

DeepWater Buoyancy has again been selected for the prestigious Marine Technology Reporter “MTR100”.  Marine Technology Reporter (MTR) magazine is the world’s largest audited circulation publication serving the global Marine Technology Market. This month, MTR released its 12th Annual Listing of 100 Leading Subsea Companies.

In his opening editorial, Gregory Trouthwein, MTRs Associate Producer and Editor, said, “This year we saw another record number of applicants from around the globe for inclusion in our annual innovation showcase. This year’s MTR100 features technologies from 13 countries and four continents…”  DeepWater Buoyancy is proud to be amongst a distinguished collection of companies that include: Teledyne Marine, General Dynamics, and Sonardyne International, to name just a few.

In addition to being selected, a short article about DeepWater Buoyancy was included in the publication.

MTR100 Article

DeepWater Buoyancy Inc. reports that it is the world’s largest producer of subsea buoyancy products for the oceanographic industry and has a vast product line of buoyancy solutions for offshore oil and gas, energy and technology companies. This product portfolio has been built over the course of 35 years serving these industries. Though products for shallow water applications are offered, the company specializes in deepwater, providing solutions to depths of 6,000 meters and beyond.

DeepWater Buoyancy’s headquarters and manufacturing operations are located in New England, the birthplace of syntactic foam. New England is also where David Cook formed Flotation Technologies (Flotec). Incorporated in 1979, Flotec grew into a recognized world leader in the manufacture of deepwater buoyancy products that included ADCP Buoys, distributed buoyancy modules and drilling riser buoyancy. Flotec was purchased in 2008 by a subsea equipment manufacturer.

In 2013, DeepWater Buoyancy acquired the rights and designs for the legacy Flotec material technology and products when its parent company was in the process of closing the New England facility. Since then, DeepWater Buoyancy has been producing, improving and growing the Flotec product line, which has been the industry standard for decades. DeepWater Buoyancy also stocks parts for these legacy products and provides design and application assistance.

At the heart of the DeepWater Buoyancy product line are the subsurface ADCP buoys. These buoys were originally developed for Teledyne RD Instruments’ ADCPs. Consisting primarily of both spherical and elliptical buoys, the product line also includes the unique StableMoor® Mooring Buoys. These torpedo-shaped buoys are engineered to house ADCPs and other sensors for high current data collection applications. By design, the StableMoor® reduces drag and increases mooring stability in extreme flow regimes, thereby producing superior data sets.

However, DeepWater Buoyancy’s product line goes well beyond ADCP buoys. In the oceanographic market there are bottom mounts, instrument collars, and cable floats. For offshore oil and gas, there are installation blocks, modular buoys, deepwater marker floats and ROV buoyancy. In addition to DeepTec® syntactic foam products and custom-engineered components, there are also polyurethane and fabricated metal products for use subsea.

Learn More

Download a copy of the MTR100 publication HERE

See the DeepWater Buoyancy product portfolio HERE

About DeepWater Buoyancy, Inc.

DeepWater Buoyancy creates subsea buoyancy products for leading companies in the oceanographic, seismic, survey, military and offshore oil & gas markets.   Customers have relied on our products for over thirty-five years, from the ocean surface to depths exceeding six thousand meters.

For further sales information:  Dan Cote, Sales Manager  |  sales@deepwb.com  |  +1 207 502 1400

For further company information:  David A. Capotosto |  davidcap@deepwb.com  |  +1 207 468 8545

We are Exhibiting at Oceans 17

We are Exhibiting at Oceans 17

DeepWater Buoyancy is exhibiting at the Oceans 17 conference in Anchorage Alaska. The conference begins on September 18th.

Visit Us

Please come visit us at Booth 716 and meet Dan Cote, Sales Manager.  Dan will be joined by Matthew Henry, DeepWater Buoyancy’s Plant Manager.

About the Conference

Every autumn, the Marine Technology Society and the IEEE Oceanic Engineering Society sponsor OCEANS, a prestigious conference/exhibition that draws an international audience of more than 2,000 attendees:

  • Over 500 professionally reviewed technical papers, including sessions focused on local themes.
  • Plenary sessions with leaders from industry, academia, the military and government.
  • 100+ exhibitors showcasing the latest innovations in products and services.
  • A student poster session featuring outstanding projects from around the world and other student activities.
  • Tutorials, workshops, demonstrations, government listening sessions, social/networking opportunities, professional field trips …and much, much more.

Learn More

More about the conference… oceans17mtsieeeanchorage.org

Send us an email to schedule a visit at the show… sales@deepwb.com

Representative Spotlight – Saderet Ltd. in the UK

Representative Spotlight – Saderet Ltd. in the UK

DeepWater Buoyancy has the finest international representative network for oceanographic subsea buoyancy.  What follows is the next in a series of articles on our representative groups.  This time we are highlighting our representative in the UK – Saderet.  Founded and still led by Andy Smith, Saderet is another of our representatives who have many years of experience integrating our buoyancy solutions into subsea moorings and structures. Saderet services our customers in this region from the National Oceanography Centre in Southampton to the Scottish Association for Marine Science in Scotland, in applications ranging from ADCP deployment to monitoring of aquaculture to support of offshore oil and gas operations.

Introduction

Since 1998 Saderet has successfully served the land and marine survey industry with leading products and solutions. Founded by Andrew Smith the company now employs 7 and is based in the Isle of Man. Geographically the company offers equipment worldwide with a particular emphasis on the UK, Europe including Eastern Europe, the Middle East and Russia.

The company specialises in representing manufacturers of complimentary equipment so that complete equipment packages can be provided from one source. An example of this is Deepwater Buoyancy whose sub-sea platforms are offered in tandem with oceanographic instruments also represented and supplied by Saderet.

Representation

In addition to Deepwater Buoyancy the company also represents the following offshore equipment manufacturers including:

  • Teledyne RDI Acoustic Doppler Current Profilers and associated oceanographic instruments including CTD’s.
  • Teledyne Odom single and multi-beam sounders for seabed mapping together with the associated speed of sound measurement systems.
  • Teledyne TSS gyro compasses, motion sensors and pipe/cable trackers.
  • Hemisphere GNSS. Saderet is the official HGNSS Distributor for Europe and the Middle East and has established a 45 strong dealer network to promote and support the navigation and heading systems product line. The company also offers OEM board level receivers and Saderet assists customers in the integration of these products into their own systems.
  • QPS software packages for hydrographic survey, dredging, rig moving and many other offshore engineering applications.
  • Edgetech acoustic release systems for subsea equipment recovery. Edgetech also offers side scan sonar and sub-bottom profiling systems for vessel towed or AUV/ROV mount.
  • Satel UHF and VHF radio modems for data telemetry, DGPS, RTK and vessel tracking applications such as rig moving operations.
  • Chesapeake Technology sub-bottom data acquisition and processing software for geotechnical studies including offshore site surveys.

Services

Saderet also supports clients with installation, technical support and training services as required. This is backed by factory trained engineers with many years of offshore industry experience. The company also offers first line repairs to keep customers operational, and some product lines are offered from stock to help with fast mobilisations.

Markets

Principle markets for the company include land and marine survey companies, harbours, container ports, universities, Government marine institutes, fish farms, OEM system integrators, dredging contractors, superyachts, racing yachts, marine archaeology, ROV and autonomous underwater/surface vehicles, pilotage, TV outside broadcast, precision agriculture, and fellow marine equipment suppliers and rental organisations.

Learn more about Saderet Ltd.

www.saderet.co.uk

About DeepWater Buoyancy, Inc.

DeepWater Buoyancy creates subsea buoyancy products for leading companies in the oceanographic, seismic, survey, military and offshore oil & gas markets.   Customers have relied on our products for over thirty-five years, from the ocean surface to depths exceeding six thousand meters.

www.DeepWaterBuoyancy.com

Saderet Office Isle of Man UK

Saderet offices on the Isle of Man.

Mooring Matters:  Mooring System Numerical Modeling

Mooring Matters: Mooring System Numerical Modeling

For the next installment in our series of technical articles, Dean Steinke of Dynamic Systems Analysis Ltd., discusses the role of finite element-based simulation and visualization software in mooring design. 

He demonstrates this capability with a video of the simulation showing an analysis of our three different ADCP buoy geometries – spherical, elliptical and the unique StableMoor® design.

 


Mooring System Numerical Modeling

“Don’t let the ocean knock you down.”

Using dynamic analysis software to assess mooring deployment, recovery, and performance in current and waves.
By Dean Steinke, PEng – April 5, 2017

Introduction

For many years moorings have been designed using basic mass-drag-buoyancy calculations, spreadsheets, rules-of-thumb, black magic scripts, and a dose of ‘salty-sea-dog’ experience. With these methods, we can frequently estimate a line size to use or an approximate anchor weight. But sometimes despite our experience we still have questions. This article looks at increasing the precision of mooring analyses using numerical modeling software designed for ocean engineers.

Software for single point moorings has come a long way in recent years. Finite element-based cable analysis programs have been tested and developed by oceanographic institutions and ocean engineers for various purposes (towed bodies, ROVs, moorings, etc.). However, their use has been typically limited to a few advanced numerical modelling specialists who had both the expertise and patience to wade through the complex analysis process. In recent years, increasingly-refined software has been developed. This software has benefited from increased computational power and advances in 3D graphics. We can now get a much clearer picture as to what is happening with our moorings subsurface through simulation and visualization.

The video below demonstrates an analysis carried out by my firm, Dynamic Systems Analysis Ltd, using our ProteusDS software. Based in Canada, we have cut our teeth over the last decade simulating many different types of ocean technologies, including single point moorings.

Analyzing Buoy Pitch and Knockdown in Current

The video shows four buoys of various styles (spherical, ellipsoid, and streamlined) being loaded by current. As the current ramps up to 3.6 knots, the knockdown and pitch of the buoys increase. There are two key forces at play – buoyancy and drag. The buoyancy provides a vertical restoring force that keeps the buoy from pitching. Conversely, hydrodynamic drag pitches the buoys about their mooring connection point.

A pitch of greater than 20 degrees is not recommended for ADCPs, as the inclinometers which allow for compensation of buoy pitch typically only have a range of 20 degrees. Mooring designers would try to limit ADCP buoy pitch to only a few degrees if possible. In addition to uplift and drag, buoy pitch also depends on the length of the mooring and weight of mooring equipment (chain, shackles, line, etc.).

The example shows that increased buoyancy is effective in preventing knockdown and limiting pitch, as the AF49-750 buoy has the lowest pitch and knockdown of the elliptical and spherical buoys. However, this buoy still pitches significantly at the higher currents, whereas the streamlined StableMoor® buoy, with its reduced drag and configurable connection point, is effective at maintaining low pitch and knockdown.

The ProteusDS model uses 6 degrees of freedom for the buoys (heave, sway, surge, roll, pitch, and yaw). Although this case is essentially 2D, the solver solves for the position in 3D. The effect of the attachment point and location of drag loading affect the pitch calculated by the software.

Figure 1 The ProteusDS software pre-processor is shown. This software allows users to add mooring elements such as shackles and swivels from a central library. Line types such as Amsteel Blue or wire rope can likewise be selected.

Transient Loading and Acoustic Release Damage During Mooring Deployment

One aspect not often considered by mooring designers is what happens during deployment. As shown in the video, the simulation allows for prediction of launch transients, which ensures that shackles and lines are properly selected to handle the deployment loads.

We’ve observed that acoustic releases get damaged during deployment when they are placed too close to the anchor. ProteusDS can be used to check that the acoustic release’s downward momentum will not cause it to crash into the seabed or anchor.

Mooring Systems ADCP Simulation

Figure 2 Mooring deployment analysis showing launch transient loading.

Mooring System Recovery

A few questions I’m asked from time to time are: How long will it take for the mooring to come to the surface? and, How far might the mooring drift as it comes to the surface? The mooring recovery section of the video shows how you can assess this.

In the case considered, the AF36-750 mooring rises at about 2.7 meters per second. If this mooring was deployed at 750 meters, it would take between 4 and 5 minutes to surface!

Although no current was applied in the example, current can be applied in the simulation to determine how far it might drift in the time it takes to get to the surface.

Mooring Systems ADCP Simulation

Figure 3 ProteusDS post-processing software showing rendered view of the mooring systems being tested.

Interaction of Waves with Subsurface Moorings

Much like current, waves can cause an ADCP mooring to pitch and move. The example in the video shows the impact of the subsurface orbital wave motion on the mooring line and buoy. A JONSWAP wave spectrum is simulated to check how much the buoy will pitch. Clearly, in this case, a bottom mounted ADCP frame would be preferred – but we don’t always have the equipment we need on hand. It’s good to have tools to check the impact of waves on our moorings.

Conclusions

DSA has carried out a series of simulations in consultation with DeepWater Buoyancy using our ProteusDS software. The software is designed to help mooring designers and builders to answer practical questions about mooring performance. Most would agree that the software’s 3D visualization capabilities shown in the video are really cool, but I believe that the real value of the software is that we don’t have to speculate what is happening subsea. We can now get a clear picture.


About Dynamic Systems Analysis Ltd.

Dynamic Systems Analysis Ltd. is an ocean engineering consultancy and software company based in Canada. DSA provides progressive and accessible dynamic analysis expertise and software to enable those working with vessels, structures, lines and technologies in harsh marine environments to reduce risk. DSA provides software and services to the aquaculture & fisheries, defence, marine renewable energy, naval architecture, ocean technology, and offshore sectors.

Learn more at www.dsa-ltd.ca

About DeepWater Buoyancy, Inc.

DeepWater Buoyancy creates subsea buoyancy products for leading companies in the oceanographic, seismic, survey, military and offshore oil & gas markets.   Customers have relied on our products for over thirty years, from the ocean surface to depths exceeding six thousand meters.

Learn more at www.DeepWaterBuoyancy.com

 

www.flotec.com is no longer active.


You have been redirected to the website of

DeepWater Buoyancy has acquired the rights and designs for legacy Flotation Technologies (Flotec) products. We have been building these products and serving former Flotec customers since 2013. We invite you to look around our site and contact us with your needs.

View Website