As the global economy continues to improve and populations advance in the coastal areas around the world, the demand for commercial dredging services and effective marine construction capabilities are increasing at a steady pace.
To help improve accuracy and efficiency, marine contractors are using marine construction visualization systems, which can also aid the speed of dredging, piling placement and surveying workflows. These new tools allow operators to ‘see’ the design and the dredge tool in real-time, relative to the waterway bed, all from an on-board display inside the cab. These systems provide precise measurement, positioning capabilities and 3D visualization to improve marine construction productivity, efficiency and safety. Applications for today’s marine construction visualization software include projects such as dredging, monopole/caisson placements, building breakwaters, piling for wharfs/piers, rock dumping, and excavating, as well as hydrographic applications such as surveys, or tracking dredge progress.
Project planning tasks, such as estimating and bidding, project monitoring and client communications are all enhanced with the 3D visualization technology. This article will highlight considerations for selecting next-generation 3D marine visualization systems, primary benefits and ROI potential, as well as strategies around implementation.
Marine Visualization Software Components
Accurate marine positioning technology and 3D visualization systems are both critical because they can help contractors avoid spending excess time and money over-dredging, dredging outside the plan or performing rework that could involve the expense of returning equipment to the site. Not only can marine visualization systems help companies better compete in tight margin projects, but the software’s documentation and reporting capabilities can instill confidence that contractors are delivering and reaching depths promised in a timely and expected manner. Marine contractors can get paid precisely for the amount of material moved, with support from data-driven reports and visual documentation.
Leading 3D visualization systems can support many applications for dredging, including dredging with a backhoe/excavator, grab/clamshell, cutterhead or bucket. The systems can also help with rock dumping and caisson placement; block placement using wire crane or excavator; vertical and raked pile placement; Inspect, Repair and Maintain (IRM); and single beam and multibeam hydrographic surveying.
At the heart of 3D visualization capabilities is marine construction software that provides real-time visualization of the dredge tool, showing the operator the actual versus the planned surface being constructed. Depending on the scope of their business, contractors should select software that can be used effectively with a variety of dredge tools, from standard buckets to clamshells, dredge pumps, drills and more.
With visualization technology the operator has a real-time view of the dredge and barge in plan and profile views. For an excavator dredge, the position of the bucket relative to design is tracked continuously and displayed. A color-coded Digital Terrain Model (DTM) highlights the high and low spots compared to the design. The model is updated in real-time from the position of the bucket teeth and the bucket width, which, as a result, tracks the progress of the dredging work.
For projects that require an extra level of confidence and data validation, look for systems that support real-time sonar inputs for as-building capabilities. Combined with 2D and 3D sonar technology, dredging companies, and those focused on hydraulic engineering, construction, offshore and surveying, have an even greater underwater vision in the most challenging inshore underwater environments and conditions.
Verification and Improved Safety
With regards to the as-building capabilities of the system, the ability to generate a 3D point cloud of the work to visualize the underwater structure will directly boost productivity. The ability to see the underwater environment in the proximity of the work zone removes the need to conduct costly intermediate inspections with ROV’s or divers, while reducing the risk to personnel operating in the potentially hazardous marine environment.
The use of a tool that can introduce motion for remote sensing devices is also beneficial. A simple barge can then be used as a platform for scanning an area, removing the time and expense of surveying from an additional vessel. The productivity of the system can be further enhanced by removing the need for post processing because the system can compensate for motion and geo-referencing a point in real-time. For instance, a DTM can be created from the work at hand and can be combined with a proper profile plot to serve as validation of the completed work.
“Sonar technology along with 3D visualization systems give contractors a greater ability to inspect, maintain, repair and survey in real-time while on the jobsite, or remotely monitoring progress,” said Ted Germann of Teledyne. “They combine to provide an even clearer picture of what’s happening with dredging, marine construction and IRM efforts because it brings a verification phase to the process. Marine contractors should consider the ability to integrate sonar into their workflows with scalable 3D visualization software. Together they can provide a true competitive advantage by improving accuracy and reducing the potential need for rework.”
One of the benefits of using marine construction visualization systems is that machine operators can set over-dredge and under-dredge tolerances on the profile view of the dredge head. A 3D picture gives the operator an explicit visual representation of where they need to position the dredge head underneath the water, with a goal of removing material precisely according to the design as indicated on the on-board screen.
When comparing marine software systems, contractors should consider systems that provide real-time sensor data gathering, computation, display and logs. Options to display data either graphically or alphanumerically and to present the data in the form of models, tables, files, volumes, nautical charts or reports gives operators and managers instant access to project information in a form that is easy to understand and communicate with others. The ability to track cumulative production calculations and produce reports about dredge progress is important because it can help contractors meet and document benchmarks and keep operators focused on the task at hand. Reports that show progress by runline, operator or job, make it easy for project managers who are remote to see accurate progress and deliver project tracking reports directly to the customers for validation and payment.
Selecting Hardware Components and Accurate Positioning Systems
For marine construction visualization systems to work, they rely on advanced hardware components and positioning systems. Marine receivers and positioning sensors on the dredge, barge and excavator are continuously feeding the software data for accurate roll, pitch, heave and location information. Additional components include in-cab displays, surface viewing screens, GNSS receivers, pitch and roll sensors, and communications (e.g. Wi-Fi, Radio or cellular). Excavator dredges also require angle sensors on the boom, stick and bucket. When a barge is used, it can also be fitted with a GNSS heading bundle, inertial motion unit and a commercial-grade Wi-Fi connection. These marine receivers and positioning sensors provide the ability to monitor tidal and other water level changes in real-time. Today’s most advanced dual-frequency, real-time kinematic (RTK) receivers deliver precise dynamic positioning with 20 mm (1-inch) accuracies, 20 times per second with a latency of less than 20 milliseconds (or higher latencies positions of 10 mm (0.5-inch) five times per second).
Depending on the accuracy required, these receivers receive corrections from a traditional base station or other sources such as RTK positioning GNSS correction services. When evaluating options, it’s also imperative for contractors to consider whether they need a permanently installed GNSS heading and positioning solution, or if they require a flexible system that can be quickly transferred and deployed to different vessels.
Conventional marine construction technology, including marine sensors and other hardware components, have in the past been notorious for having connection failures, downtime or other maintenance related issues. Today however, modern systems are much more reliable and robust. Consistent uptime from every sensor and 3D visualization component is necessary in order to collect accurate data and to ensure enhanced production over the life of the project.
Historically, it was also common for contractors to rely on a piecemeal approach where they purchased hardware, such as sensors, from different manufacturers. In most cases, each vendor had a proprietary software package for hydrographic survey, design and data analysis. This could be challenging for operators because it requires them to learn various software packages from multiple manufacturers. It increases the risk of project-stalling compatibility problems with file formats and workflows.
With a more integrated implementation operators deploy marine-specific hardware and software from a single vendor, which eliminates the potentially costly risk of integration challenges that can cause slowdowns or missed opportunities.
3D On-board Control Box and Displays
Today’s advanced 3D marine visualization systems also include an in-cab display or control box and surface viewing screens. These components are deployed on the vessel or machine to give operators a real-time overview of the excavator and barge in multiple views. Compared to conventional 2D marine software capabilities, today’s 3D systems can accurately display and record complex design surfaces and a 3D display of the bucket as it breaks the seabed surface. This capability is critical because it guides the operator back to the last dig each time work begins. This is an essential feature when projects take place over several weeks or when machines need to stop at designated times to keep shipping lanes clear. During the selection stage, it’s crucial that contractors look for control boxes that can process large data sets from multibeam progress surveys to more clearly and effectively show the updated dredge surface as the job proceeds.
Control boxes and displays should also be customizable giving lead engineers the ability to set up the screen to meet their exact preferences and to sync up with existing workflows. Displays that have larger screen sizes and clearer screens enhance 2D and 3D profile information, grade guidance and warnings. Keeping in mind that displays that keep it simple for the operator, help them focus on the task at hand, while providing adequate warnings and other indicators to help them be aware of other critical environmental conditions.
Reporting capabilities tied directly into the visualization software and guidance technology can streamline the reporting process allowing project managers to create volume reports and other status reports directly to keep all stakeholders up-to-date on project progress and aware of any changes or sensitive environmental conditions, as needed.
Return on investment (ROI)
When considering marine construction systems, consider the payback in terms of improved accuracy, uptime and preventing problems before they happen. For a harbor dredging project, the systems should be able to achieve vertical accuracy to +/- 100 mm. When multiplied across the area of a harbor, this improvement in accuracy, can quickly add up to hundreds of thousands of dollars.
By tracking ‘as-building’ progress, contractors can avoid rework and the potential to return a machine to a site after the survey when areas may have been missed or material has moved. Real-time progress reports also provide an early indicator if the project will be delivered on-time.
Accuracy and Validation
With the right marine construction visualization system and implementation strategy, contractors involved with marine construction, hydrographic survey and dredging operations can expect substantial ROI in terms of increased dredging speed and accuracy, as well as reduced risk and improved jobsite safety. Improved documentation and validation capabilities from the software will also enable contractors to more quickly and accurately bid projects and track material movement.