Automation advances in dredging
Photo Credit: Jan De Nul
An increasing number of newbuilt dredgers are fitted with automated systems, which allow companies to streamline various work processes such as slurry pumping, dredge positioning and swing speed of cutter head. This technology, which can sometimes be found on retrofitted vessels, facilitates more precise dredging, boost safety, fuel-saving capabilities, and reductions in administrative burden and project timelines - all of which reduce costs and improve project performance. This streamlining and fuel reduction can also directly lower carbon emissions, which will help these vessels meet IMO GHG reduction targets - mandatory by 2030 and 2050.
There are currently four degrees of Autonomous shipping as defined by the IMO:
Degree one: Ship with automated processes and decision support: Seafarers are on board to operate and control shipboard systems and functions. Some operations may be automated and at times be unsupervised but with seafarers on board ready to take control.
Degree two: Remotely controlled ship with seafarers on board: The ship is controlled and operated from another location. Seafarers are available on board to take control and to operate the shipboard systems and functions.
Degree three: Remotely controlled ship without seafarers on board: The ship is controlled and operated from another location. There are no seafarers on board.
Degree four: Fully autonomous ship: The operating system of the ship is able to make decisions and determine actions by itself.
Automating dredging
The heavy technical requirements of the dredging sector make it a good candidate for automation of some systems, but make it unlikely to become fully autonomous in the near future. What is more likely is that technology being developed in other sectors such as shipping and the offshore oil and gas industry will trickle through to dredging. This includes autonomous underwater vehicles (AUVs) for underwater inspections, surveying and maintenance support. Some technology is also able to perform simple dredging and equipment installation.
One of the reasons that autonomous dredging vessels are not yet on the horizon is the complexity of the projects, which could have serious environmental consequences if performed incorrectly. Automation works within set parameters to perform pre-determined functions. This means that if the technology or equipment encounters unexpected conditions, it will not use its judgement but will keep performing its task until it is told to stop - irrespective of consequence.
Human intervention can prove vital when working in complex locations containing coral reefs or gas pipes. While the future may allow the use of artificial intelligence that could better assess situations, the current technologies are better suited to automate fixed tasks under human oversight (either in person or from a remote location).
There are also ongoing discussions about liability in the event that something goes wrong, with questions of who would be responsible: the programmer of the automated system, the software seller, the company operating the vessel, certifying body or the client. While these conversations are still in their infancy, it is likely that they will advance in step with autonomous technology.
Newbuild installations
Although vessels with onboard automated systems are a fairly new technological advancement in dredging, they are increasingly being found on newer dredgers. Van Oord's commission for three dual-fuel trailing suction hopper dredgers (TSHD) in February 2022 continued their fleet expansion of automated vessels. The second vessel arrived in December 2022, with the last vessel, Vox Alexia, scheduled to arrive in 2023.
The purchase, which was part of the Dutch company's innovative investment programme and sustainable fuel strategy, focused on reducing the company's carbon footprint. The TSHDs work by reusing energy and optimising the installed automated systems in combination with electrical drives. The vessels have a high degree of automation for their marine and dredging systems, along with onboard data acquisition and an integrated control system to enhance efficiency and reduce operational costs.
The fully automated dredgers of the future may also reduce fuel consumption, as all human-centered facilities will become redundant, thereby freeing up space and weight. As a result, the vessel would be lighter on the water and require less fuel for propulsion.
Retrofitting systems
Automation systems are also available for older vessels, with quick and easy retrofit options. In October 2022, Dutch electrical technology company Alewijnse delivered its latest dredging automation system to Great Lakes Dredge & Dock, the largest provider of dredging services in the US. Installation of the automation system occurred onboard Liberty Island, a large TSHD built in 2002.
In January 2023, Jan De Nul signed a contract with Royal IHC for the upgrade of the J.F.J. De Nul. The vessel, which is the second largest cutter suction dredger in Jan De Nul's fleet, was built in 2013 by Royal IHC with a total power of 27,240 kW. The automation upgrade will extend the vessel's operational capabilities for another decade.
Vessels with existing automated systems can benefit from updates in technology. Boskalis' TSHD Oranje was recently extended from 156m to 201m at Keppel Shipyard in Singapore. As part of this expansion, the ship's automation system also received an update, with Praxis Automation replacing the Pro Series Mega Guard system with the latest E Series version. This update has increased the system's capacity for data traffic, helping to maximise its potential activity and production output. The availability of installation and upgrade services for automated systems shows that there is certainly a market for this technology in dredging.
Safety Culture
Human error is considered amongst the biggest causes of maritime accidents - and one that can be addressed through the use of automation. Fatigue, misjudgement, and distractions are just some examples of human error which can impact dredging operations - and, proponents of automation argue, would not be prevalent if the tasks were automated. Furthermore, in the early stages of automation (degree 1 and 2) it is likely that increased automation would reduce both the workload and administrative burden for crew and give them more time to perform complex tasks to higher levels.
As automation becomes more mainstream the industry may utilise this technology as a way of enhancing safety culture in the workplace. However, although accidents as a result of human error can be mitigated by the use of automated systems - others can be introduced as a result. As mentioned earlier, machines can only operate as per their programming and are unable to make judgement calls if a situation is more complex than anticipated. There are also concerns about cyber security and the possibility that equipment can be remotely hacked.
Safety and the environment
Even with effective management systems in place, dredging, like other types of maritime work, can pose a number of hazards, risks, and the possibility of accident and injury. Most dredging companies have their own Quality, Health, Safety, and Environment (QHSE) management systems that ensure that employees are kept safe on projects.
The new addition of the environment to health and safety management plans to better incorporate decarbonization strategies, is also supported by automated systems. Automated systems can save energy, power, and reduce emissions for a vessel and an overall dredging project.
Furthermore, dredgers that use automated precision dredging machine heads can help reduce turbidity, the spread of sediment, and the potential risks associated with the dumping of sediment. These precision dredging heads offer highly accurate operations, allowing for dredging to occur only where necessary, minimising a project's impact on the environment.
Future of automation
Advances in established and emerging technologies such as artificial intelligence, machine learning, and wireless sensors mean that the industry is gradually moving closer to degree four. C-Job Naval Architects is one company that has been conducting research and development of autonomous dredgers for the last few years.
The development of an autonomous underwater maintenance dredger in 2020 and the subsequent design for an autonomous low energy replenishment dredger show the possible future of autonomy in the dredging industry. The Dutch company’s work is largely conceptual, but through simulation testing, it is able to demonstrate how an autonomous dredger would operate.
Programmers and vessel designers are also likely to import technologies and lessons learned from sectors such as oil and gas (see above), rail, and of course, road. The latter is particularly important to address the issues of liability as these are being heavily debated in the public sphere. The advances in regulations, specifically a MASS (Maritime Autonomous Surface Ships ) code for shipping, will also influence the pace of change.
While the road may be rocky, the wider maritime industry is definitively moving towards greater degrees of automation and lower reliance on human operation - and these changes will trickle down to dredging. The question remains if we can harness the advantages that this technology brings and ensure a safer, greener and more efficient future.
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