New technologies and innovations are needed as the salvage sector tackles ever-more complex projects with larger ships to protect mariners, assets and the environment
This has been publicly demonstrated with the gradual removal, in Q4 2020, of the Golden Ray car carrier that capsized in Georgia. Salvage companies have also been in the media spotlight with the removal of Newcastlemax bulk carrier Wakashio off a Mauritius reef.
Faced with greater challenges, salvors are increasingly seeking innovations to enable more advanced wreck removal and distressed ship assistance projects. Here are some innovations being developed for the sector:
Giant lifting systems
The Golden Ray wreck removal demonstrated a need for specialised cutting and heavy-lifting systems. Bigger vessels such as ultra-large container ships and bulk carriers, LNG carriers and vehicle carriers increase salvage requirements when these get into trouble. Projects become further technically challenging when these ships become wrecks in shallow water on reefs or estuaries.
Golden Ray ran aground onto its side outside the Port of Brunswick in September 2019. Its salvage required a tailored cutting and heavy lift crane vessel, VB 10,000 to be constructed.
The wreck’s bow section was sliced and removed in late November 2020, then secured to barge Julie B for transportation to Louisiana for recycling. Salvors will remove the rest of this wreck in seven more sections while the site remains contained and the surrounding environment monitored.
There are other wrecks worldwide yet to be removed from islands and coastlines which require heavy lifting and powerful emergency towage tugs.
Early information on a salvage and wreck removal project is precious. Salvors have explained how they need the latest information and data from a wreck or grounded ship before committing assets and putting their people in danger.
One of the best methods to understand a salvage project and its challenges is by viewing it. This is why salvage companies are deploying drones before sending in their people. Smit Salvage uses drones early in salvage operations to reduce the risk to its personnel and gain information on the condition of the casualty.
Unmanned aerial vehicles can be equipped with cameras and sensors, such as infrared for heat and night vision. They can be remotely controlled from a mother vessel with the video streamed to shore, dependent on broadband communications, which may need to be over satellite in remote locations.
This information can be analysed prior to commencing the project, providing data to salvors, owners and insurers to ensure the right equipment and strategy is implemented.
3D models to digital twins
Developments in underwater survey, sonar, graphic simulation and computer power has enabled 3D mapping of ship casualties. This information is vital for removing a wreck.
Companies such as Waves Group provide these graphical capabilities using ROV footage, spatial measurements, laser data above and below water, and high-resolution multibeam sonar.
The data is used to generate a 3D model of the casualty including the hull, bulkheads, cargo, fuel tanks and above-deck infrastructure.
Waves Group lead for digital services, and SeaArch co-founder Mark Lawrence said 3D models enable “more informed decisions and increase situational awareness for salvors”.
Much more can be gained through processing these 3D models. “They reduce the unexpected and enable decisive actions for enhancing engineering solutions through data collection,” said Mr Lawrence.
From these models, salvors can take cross sections, identify the location of residual fuel or lifting points. They can overlay general arrangement plans and set out sampling plans, possibly using a neutron backscatter device, to understand the volume of remaining oil.
This enables salvors to “get a full understanding of the wreck to inform the risk analysis for oil removal and then removing the entire wreck,” said Mr Lawrence.
Building this 3D model requires a succession of images or data points to derive a point cloud, and using scaling data to improve its accuracy.
From this model, salvors can create a digital twin of the casualty and examine mesh models for finite element analysis to identify stress points or strengthened lifting areas. With multiple surveys they could monitor the casualty condition over time.
Autonomous emergency response vessels
Salvors are sometimes faced with fire or gaseous conditions that are highly dangerous to humans. When dealing with these scenarios, they would usually bring in a crewed fire-fighting vessel or tug, perhaps even several depending on requirements.
There should be a way of tackling fires without putting humans in harms’ way. Naval architects such as Robert Allan have developed unmanned fire-fighting vessel designs. There is interest in building and testing these, but so far no firm projects.
There are also projects to test using autonomous navigation on oil spill response vessels using technology developed by Sea Machines Robotics and others.
So far there have only been successful trials, such as those conducted in the US. But as autonomous vessels are built for offshore and marine survey by Ocean Infinity and others, an unmanned fire-fighting vessel becomes more likely.
Exoskeletons and robotics
Most salvage operations require human interaction, whether divers or people on deck, even if it is just to position a towing line.
Although there have been studies into using drones to transit lines between vessels and tugs, there still needs to be people on site. This could change with the use of robotics and remote control technology.
Before the industry trials this type of technology, it could consider raising the strength of personnel when they are on a casualty. Some on-deck heavy lifting could be required to clear areas before a tow, or removal of cargo.
Exoskeletons could be the answer for times when it would be too difficult to bring in a lifting system or vessel. They have been developed for military applications and considered for shipbuilding, but with little trials so far. But these carbon-fibre exoskeletons could enable salvors to lift heavier equipment. Or robots on deck could be remotely controlled from a master vessel.
These technologies would improve situational awareness far earlier in a casualty salvage or wreck removal. They would remove the danger to humans from operations, or assist those on site to perform activities more effectively. These technologies will enable salvors to tackle more complex projects as larger ships with different cargoes become maritime casualties.