Blog • Page 6 of 9 • Stewart Technology AssociatesStewart Technology Associates | Structural, marine and offshore specialists | Page 6

Learning From A Past Single Point Moorings Accident

[Posted on April 9th 2014 by Bill Stewart]

Bookmark and Share

There are many considerations in the marine industry that can pose possible threats to industry property and employee well-being. Understanding those considerations and possible risks is crucial to running a safe and profitable operation. One of the key elements to keeping your own company and your  employees safe is to understand risk factors, and to keep yourself well informed of current and past catastrophic marine events as they pertain to equipment similar to your own. Single point moorings are one tenant of marine industry which can pose a threat to your business and employees when all safety measures are not adhered to. Although every operation would like to boast a zero accident rate, this is rarely the case. When catastrophic failures do occur, fellow marine industrialist would do well to pay attention and learn a lesson.

One recent accident involving the single point moorings of a deep water GOM operation makes an appropriate object lesson. In 2011 this operation experienced a failure at the tether chain of a free standing hybrid riser. This catastrophic failure caused the buoyancy can and free standing flow line riser to separate. The air can, weighing 440 tons rose suddenly to the surface while the riser suffered complete collapse. The event was investigated thoroughly in order to establish just what might have caused such a large scale failure.

The investigation of the single point moorings quickly located a compromised link in the tether chain which was connecting the buoyancy air can to the hybrid riser. It was later determined that the link failed because of a past welding repair which had been performed on it. The investigation determined that the defect in the link had been grinded down. The  void was then filled with weld material. Once heat treated welding repairs are not permitted in accordance with DNV’s chain standard. It was also found during the investigation that three other links in the tether chain had also been repaired in a similar way, compromising the structural integrity of these links as well.  Weld repairs of this nature create a weakness making the links more susceptible to cracking.

Although in this incident there were no employee injuries or fatalities to report, the risk factor was great. Avoiding such risk should be a critical part of your business plan.

Stewart Technology has been helping marine industries understand and assess risks like these for years. Our expert consultation services can help educate you and your employee base on the best and safest marine practices concerning your single point mooring system and steel catenary risers.

The Importance of Seakeeping Analysis

[Posted on April 2nd 2014 by Bill Stewart]

Bookmark and Share

If you have a watercraft, then the main thing you may think about is how much fun you have with the vessel. While this is important, you should always be aware of the safety. This is why it is important to have a Seakeeping Analysis done. There are a few things to keep in mind with this.

What is Done With This?

One of the best ways to see how important this analysis truly is is to see what all is done with this. The environment will be analyzed as this plays a pivotal role with any watercraft. With this they will look at the way the ship responds to different situations  as well as factors that may affect seakeeping with the boat or ship. This could include aspects such as the size, stability, displacement and more. One of the biggest things they look at is the human factor as this is what will play the biggest role when you are out on the water.

Chances are it is Needed

Another thing to keep in mind is that you may be required to have a seakeeping analysis done. It may be required by the government in order to get the proper licenses for your watercraft. You may also find that the insurance on the boat requires you to have this. Since it tells where the weaknesses are on the boat the insurance company will be able to fully understand the risk of insuring the vessel.

Perfect for Buying or Selling

When you are buying a boat or ship, especially if it is used, you want to make sure you understand the condition the boat is in and this analysis is one of the ways you can do it. It will help you to understand whether this is something you want to invest in or not. It is also a great tool to use when you are comparing different boats. When you go to sell your boat or ship, it is good to have this analysis done and handy as it will help to sell the boat faster as sellers will know what to expect with this vessel.

Whether you are dealing with a personal boat or a large ship for your business needs, it is important that you have a seakeeping analysis done on it. This will ensure that you understand the issues the boat has and the ways that you can correct this. When you take your boat out, even if it is to single point moorings you want to make sure you are safe as possible and that is the main reason for the analysis.

Use Riser Analysis To Avoid Incidents In The Water

[Posted on March 26th 2014 by Bill Stewart]

Bookmark and Share

Accidents happen with oil rigs and offshore drilling all of the time. There are a lot of variables at sea and you want to take them all into consideration with your drilling facility. Riser analysis is critical to ensure you have thought of everything and that all is going to go smoothly when you make it out to the sea and set up a pipeline.


There are accidents at sea every day and many of them could have been avoided. Many people simply take to the sea without giving consideration to the amount of waves, the depth of the ocean, and even the temperature of the water.


With riser analysis, you can ensure that you don’t experience any kind of disconnect. Essentially, the risers are in place to be a conduit for transferring materials from the seafloor to your drilling rig at the top of the water’s surface. If you don’t establish the riser and all of the connections properly, you can experience an oil spill as well as various other problems.


Oil drilling and other offshore projects are expensive. It is important to get in the habit of strength testing a riser before you even make it out to the water to ensure that it will perform as you need it to. If there are issues, you want to know about them as soon as possible so that you can make changes to the overall design.


A marine accident investigation is going to take place if you have an issue with your riser or any other aspect of your rig while on the water. Instead of being counteractive, you want to find out about what could go wrong and then take the necessary precautions to ensure that they don’t happen. This requires riser analysis, which can be done with sophisticated software.


Your entire rig design can be entered into a computer. This includes noting where you will be setting up your facility, the length of your boat, and how far you will be anchored from the actual drilling site. Various variables will then be entered in including the depth of the water and the wave activities. It’s nearly impossible to tell what the actual depth of the water will be when you get out there as well as how high the waves can get.


This is why a ‘worst case scenario’ is going to be drafted as well. By doing this, you can get the most in-depth riser analysis so you can focus on preparing your rig to withstand all of the forces that could be experienced while you are at sea. This will prevent you from having an accident and potentially damaging your equipment or injuring your crew.


Taking the steps to order analysis before you go out can save you money and ensure productivity.

Orcaflex Takes Ocean Engineering To A New Level

[Posted on March 19th 2014 by Bill Stewart]

Bookmark and Share

It’s important to work with a company that can provide you with detailed analysis any time you are doing work in the ocean. Orcaflex is an advanced software program that can provide you with significant analysis for marine events. This includes details to provide you with insight for any offshore drilling projects that you may be working on.

You may not always have professionals with a background in ocean engineering on staff. This means that you need to find another way to learn about the effects of currents, waves, and even the salt water environment on what you are working on.

If you have an oil rig going out into some of the deepest waters of the ocean, you need to have riser analysis performed to ensure all is being set up properly. Every material that you use can be impacted by the salinity of the water, the depth, the temperature, and various other factors. Orcaflex can provide you with reports to show you what you need to be concerned with.

There is more offshore technology than ever before. With this technology, you can ensure that you are developing the best possible methods so that your rig can withstand the forces of the waves and even protect your risers against corrosion.

Offshore drilling and other marine projects can be a significant undertaking in terms of cost and time. You don’t want to purchase supplies only to have them damaged by the first large wave because of not having valuable analysis at your fingertips. The better solution is to work with a firm that uses Orcaflex so you can find out what you are going to be up against before you get into the water.

There are a lot of things that you can do and prepare for when you know the worst case scenarios. For example, you don’t know exactly how deep the water is going to be until you get out there. However, you can ensure that you are making the best possible calculations when you have advanced software as well as professional engineers running the numbers for you.

When you place risers out from the rig, you want to be sure they stay connected. These are essentially your lines between the ship and the bottom of the ocean floor. If something goes wrong with these, you may have the next biggest marine accident on your hands and this is negative press that you and your company do not need.

Orcaflex has been tested time and again and is capable of providing you with advanced engineering reports to ensure that you have a strong rig that can go up against the environment that you are placing it in. This will help you maximize your productivity and eliminate potential problems when you are in the ocean.

Get the Right Service Using Hydrodynamic Analysis

[Posted on February 26th 2014 by Bill Stewart]

A large part of marine technology consultancy when offering services comes in the hydrodynamic analysis. Marine engineering as a broad discipline has to do with ships and rigs. Hydro means water, and dynamics means the forces and torque caused from the movement of water. Liquids in motion in the case water makes for wear and tear on ships and structures in marine environments.

Handling the Pressure

A basic course in physics will teach the ins and outs of fluid dynamics. Fluid dynamics comes as the basis of hydrodynamic analysis. Fluid constantly flows and has states. A day at the beach shows typical fluid dynamic issues. Beaches have erosion as waves come and go. Depending on the winds and how currents flow when standing in ocean water a person feels different patterns pounding on their body at different levels as water swirls around and past them. Make a change such as more wind or a motor boat come by and it all changes in an instant. A person like you can leave the water anytime but imagine a structure or ship that constantly has water rubbing it. Think about the conditions a typical storm may bring and one begins to realize that erosion on the beach happens to structures and ships. Finding ways to minimize the damage becomes a key element in hydrodynamic analysis.

Flexible Risers

Offshore oil production systems deal 24/7 with fluid dynamics of ocean water, but also the oil being pumped out of the seabed floor. Flexible risers serve as a key component of linking the platform and the well head of an offshore oil production system.  Vibration comes as a constant with all the movement of the fluid through a pipe under pressure. Keeping it all in balance to maintain maximum efficiency and productivity becomes the venue that analysis can help with. Knowing the way the process sequences will help show how to facilitate fluid movement in a way that keeps all flowing well makes the company and the bosses most happy.

Computer Models

Companies use software to input data from the client’s fluid dynamics. This allows a simulation of what occurs when water sweeps past solid material. It makes predictions of durability and erosion if the fluid dynamics continue at that level. A good analysis of the data will show ways to strengthen the material, how to make fluid flow faster or slower, and if a change in process or protocol would help move the product where it needs to go in a timely manner. It takes experts and companies with the right service to make it happen in such a complicated environment. Identify your issues today, and call a service in for your analysis. It puts more money in the pocket and increases safety.

Mooring Analysis: Critical for Selecting the Right Mooring

[Posted on March 12th 2014 by Bill Stewart]

Bookmark and Share

As any marine organization can tell you, installing mooring systems is more than anchoring a single CALM buoy or setting a fixed tower on the sea bed. It is critical to know how ships of different weights and sizes will react in the given location under different circumstances. Doing a mooring analysis is critical to determine the best mooring option and its placement.

Take tanker loading and offloading as an example. Takers are extremely sensitive to wave direction in an open water situation. In most cases, spread mooring would not work due to this movement. Tankers often use single point moorings that allow them to move around the single point based on the direction of the waves and movement of the water flow.

Determining what kind of single point mooring is appropriate to a specific application requires careful analysis. Here are a few mooring options:

  • Fixed towers with a slew ring work well in some single point applications. It works best in shallower areas where wave action is not heavy. At greater depths or in areas with heavy wave action, the tower can begin to bend. These towers are also susceptible to damage from even minor tanker bumping.
  • A catenary anchor leg mooring (CALM) are not as sensitive to water depth and wave action as a fixed tower mooring is. It is able to handle some bumping from tankers without sustaining extensive damage. Major tanker impacts though can cause damage that can put the CALM out of commission for a good length of time and cost a lot to fix. The mechanical components are also subject to extreme weather which requires ongoing, sometimes expensive, maintenance.
  • A SALM (single anchor leg mooring) solves the problem of expensive damage that CALMs can experience due to major tanker impact. They do this by placing the mechanical systems in an underwater arrangement at a depth below a ship’s keel. The simple surface buoy is easy to replace if its hit by a tanker. The biggest issue with the SALM is the maintenance difficulty and cost.
  • An Articulated Loading Column (ALC) is a mix of a fixed tower and a SALM. The tower holds the swivel and hoses above the likely point of impact with a ship. There is an articulated joint below water attached to a concrete base embedded in the bottom. This joint helps the mooring move in heavy wave action.

Determining which mooring application is right for a particular situation requires the ability to model the many factors that influence the ship and the mooring. A mooring analysis tool is essential in this process. It allows for quick and thorough modeling of a number of scenarios. Here at Stewart we use Orcaflex when we do a mooring analysis. This software package is the best marine engineering software package on the market today.

What to expect during a marine accident investigation

[Posted on March 5th, 2014 by Bill Stewart]

Bookmark and Share

Every year, the United States Coast Guard maintains records of various types of marine accidents, both commercial and recreational. Depending upon the severity of the accident, an investigation is requested. Our main goal while conducting a marine accident investigation is to prevent similar accidents from occurring in the future. Items we look at during an investigation include the loss of a ship, number of deaths, any serious injuries, any missing persons, material damage to ship and other ships, damage to area marine structures and the possibility of pollution.

After an accident has been reported, our inspectors head out to gather as much evidence as possible. We use this evidence to determine how to proceed with the marine accident investigation.  During the evidence collection process, our investigators will take photographs and video of the scene, vessels involved and any damaged equipment. In addition to photographing evidence, our investigators comb through logbooks, records and verify the qualifications and certificates of the crew.

In addition to evidence collected at the scene of the accident and from the vessels involved, we conduct interviews with witnesses and others directly involved in the incident. We may request to speak with crew, passengers, shore staff and other witnesses. During the interview process, we ask questions about the accident, as well as request any documentation the crew or witnesses may have, including photographs, sound recordings and video.

Our investigators will use the information collected to try and reconstruct the events leading up to the accident. It also helps investigators get an idea of what happened during and immediately after the accident occurred. This makes it possible to determine if the accident could have been prevented. Models, diagrams and landmark charts are used as visual aids in our reconstruction process. Computers and CADD programs help to digitally recreate the boats, structures and events leading up to the accident.

Other items we consideration during a marine accident investigation include looking into any recent safety recalls or reports of faulty equipment. We also check to see if the boat was secured to a dock prior to the accident. We will conduct a mooring analysis to ensure the vessel was tied up properly.

Documentation we use to assist with the investigation process include boat handling books, boat manufacturers owner’s manual, engine owner’s manual and various US Coast Guard instruction materials.

All information collected during the investigation will be used to determine the cause of the accident and who may be responsible. All discoveries will be listed in an investigation report that will be available to all parties involved with the accident, including stockholders and owners. In the final report, our investigators will give their recommendations for preventing similar accidents from occurring in the future.

The investigation is a long process and we make sure to cover everything from start to finish. We take pride in our investigation services, knowing we can help make a difference and hope to prevent similar accidents from happening again.

Flexible Risers for Business

[Posted on February 19th 2014 by Bill Stewart]

Bookmark and Share

When you’re starting an oil business or want to expand the offshore drilling plant you already have affordably, you may start looking into your options and discover various types of flexible risers at differing pricing levels. These risers are used in marine and offshore drilling, and they are one of the most affordable pieces of equipment that you can purchase for this type of work. These risers come in many shapes and forms, which is why most companies will buy them from a company specializing in custom risers and services for the industry. Stewart Technology Associates offers high-quality flexible risers, design, and analysis services to consumers, so you get what you need.

You expect to receive the best quality items for your oil rigs and offshore drilling requirements. Stewart Technology Associates offers specific tools that make sure you get the best, most cost-effective products. For example, Stewart Technology Associates can offer clients private riser design that will be made to suit any situation, analysis services to determine issues or benefits of different systems you’re considering, and uses OrcaFlex technology by Orcina, software used throughout the industry, to produce the best results.

The effects of cable dynamics are important, as they can impact the use of the equipment on your risers. In oil fields, mooring systems are sometimes used with flexible risers, and the cables and attachments must work correctly, or you could damage important hardware or pipelines. So, there are benefits in buying the right kinds of equipment. Steel catenaries, for example, are a type of riser that are flexible steel pipes. They run along the bottom of the ocean and are connected to floating platforms above them. These items can be used for deep-water drilling, and they can be hundreds of meters in length. Fortunately, because they are flexible risers, any changes in the flow of water, tides, or impacts can be handled well by the pipes, and the flexible design allows them to bend instead of breaking. These helpful risers will also transport potentially hazardous waste or materials through the ecosystem of the ocean, so knowing that they won’t break under minor bending pressure is vital.

Compared to other types of risers, these flexible forms are easier to manufacture and cost less overall. Even with the cost being lower, risers are one of the most affordable types. They are extremely reliable, too, and they can resist high temperatures, are flexible, and can withstand high pressure. They are often used in deep sea oil industries and in the gas industry because of their affordability and trustworthiness.

Stewart Technology Associates (USA): Experts in Cable Dynamics and Anchor Analysis

[Posted on February 12th, 2014 by Bill Stewart]

Bookmark and Share

Stewart Technology Associates (STA) is on the forefront in providing first class consultancy services in the field of offshore and marine technology. We are particularly experts in cable dynamics design and analysis.

Our clients find pleasure in working with us to access to ideal technology solutions in the related fields. We are always an edge over the others in seeing to it that the customers’ needs and interests are safeguarded. Not many can boast of accomplishments similar to what we have achieved to where we are. We are aware that consultancy is demanding, and requires total professionalism to give the best. That is one area that sets us apart from the crowd. We have reputable and highly qualified experts that know the ins and outs of their specialization. In addition, these experts have many years of experience to thank for the quality services they offer.

Trust us to help you with your cable dynamics design among other services. Our solutions are pocket-friendly and aimed at client satisfaction. They add value to the operation of the organizations that work with us helping them to reach and hit their set objectives. The long experience that we have in this field has been our stepping stone in scaling the great heights of success that is hearsay to other companies. We employ OrcaFlex, standardized software, in coming up with reliable, accurate, and easy to comprehend analysis. This software has been part of our greatest resources that has enabled us deliver according to our customers’ expectations. Our team continues to be part of success stories of many organizations in the field of marine and offshore technology.

OrcaFlex has made us move many heavy rocks and mountains. With over 50 years of superior service, there isn’t anything in marine and offshore technology that we cannot do. Among the industries that OrcaFlex has revolutionized include seismic research, defense, and oceanographic research. In defense, the submariners have identified this software program as the perfect tool for research and analysis of cable dynamics. We have also helped the separator sector, the processing technology industry, as well as the gas and oil industry to get the ideal software that is needed to make their operations swift.

We are also specialists in other services in marine and offshore technology. These are expert marine witness, CE marketing, risk assessment, design and analysis for jack up, anchor analysis, and financial assessment amongst other services. Both the public and private sectors come to Stewart Technology Associates for real and long-lasting consultancy services.

If you have a specific cable dynamics problem that you need solved, you have the experts at your service. The moment you check in with us, our team of experts will work with you for an ultimate solution to your problem. Check on us today to experience quality first hand.

Web Marketing by Server Side Design, Inc.
Owner of is entirely responsible for all content on this web site. Email