Van Oord has placed a new order with Demcon unmanned systems, this time for an unmanned, autonomously sailing offshore platform. The electric vessel is suitable for challenging offshore conditions and weeks of survey operations at sea and was tailor-made to fit Van Oord’s requirements.
Demcon unmanned systems develops and builds unmanned, autonomous sailing platforms for surveying and inspection work on the water. Van Oord already owns electrically powered survey vessels for hydrographic inspection on inland waters, the DUS V2500 types. With this order, the maritime contractor takes the step towards unmanned offshore survey.
The new vessel can be used for dredging, installation of offshore wind farms and construction of maritime infrastructure.
‘The autonomous offshore inspection platform is one step larger, must be able to sail for several weeks at sea and will have new autonomy applications for the unmanned operations,’ says Fedor Ester, managing director of Demcon unmanned systems. ‘It contains our standardised, modular autonomy system. Around this system we adapt the hull based on customer-specific performance requirements. In addition, we add new functionalities to better suit the operation.’
Ester adds that this will be the DUS V5750: ‘An easy to handle vessel that can stand on the ground without tools and fits into a 20-foot container. The vessel for Van Oord will be delivered within a year. After that, the system will remain up-to-date via our software. In this way, together with Van Oord, we are improving autonomous navigation and making wider application possible.’
Four autonomous inland waterway vessels
Until recently, measuring and inspection activities were mainly carried out by manned vessels. In response to the current trend towards digitalisation, sustainability and safety, Van Oord was looking for autonomous survey solutions. Wim Balvert, responsible for management and innovation of all survey equipment: ‘Van Oord went with Demcon unmanned systems for the complete solution. They looked at the technology on our manned survey vessels and designed an unmanned vessel for us.’
The first result was the VO:X Metiri (first DUS V2500 vessel), a robust and compact inspection platform only 2.5 metres long for deployment on inland waterways and in coastal areas. These fully electric, autonomous vessels enable Van Oord to carry out survey activities remotely, cost-efficiently and automatically. The first experiences were so positive that Van Oord has now purchased four of these vessels and has also identified applications for a seaworthy, larger version.
New functionalities for navigation at sea
For navigation at sea, the existing V2500 situational awareness system – “where am I and what do I see around me?” – will be expanded. It works at close range (150 metres) and in complex environments on the basis of 360-degree laser scanning technology with LiDARs, among other things. To see further away, different types of cameras, radar and electronic navigation chart data will be used.
Smart algorithms process the information from all these sensors and sources into a digital world model of the environment around the vessel. The DUS collision avoidance system then recognises obstacles and provides information on how to avoid them according to the rules of the water.
The communication system will also be expanded. The V2500 vessels already work with WLAN and an LTE (4G/5G) data link; satellite communication will be added for the V5750. Ester: ‘This is how we ensure that communications are also redundant. To ensure robustness, all systems must be backed up so that the vessel can always return home safely.’
Inspection during cable laying
A third innovation is specifically intended for Van Oord’s first survey application. This is an inspection (“touchdown monitoring”) during the laying of cables to and from offshore wind farms.
Ester: ‘A cable-laying vessel moves slowly and the survey vessel follows. Depending on the weather conditions, this can be technically challenging and inefficient. We are therefore developing a weather-dependent Dynamic Positioning functionality. This ensures that the vessel’s nose is in the direction of the wind, currents and waves, for the least resistance. It may happen that the vessel has to follow the cable laying vessel sideways. This may seem like an unnatural angle, but with our own innovative Dynamic Positioning system, it’s not a problem.’
The vessel is virtually unsinkable due to a watertight, segmented and self-aligning hull. This allows the system to remain operational in harsh conditions and high waves.
Ester: ‘During the design and construction process we continuously validate the vessel’s performance in our “sea keeping” simulation environment.’
For deployment at sea, the platform must be able to sail much longer than on inland waterways. The V5750 will therefore have more batteries and if these are not enough, a hybrid drive can further extend the time at sea to thirty days.
Optimal deployment of people
In addition to cable laying, Balvert sees other opportunities for Van Oord, such as in sand suppletion off the coast or as a platform for using drones to inspect wind turbines.
Balvert: ‘With the electric unmanned vessels of Demcon unmanned systems, we can work more sustainably, more safely and optimally deploy our employees. On a manned vessel, surveyors sail along to a project, with an autonomous vessel they only hook up remotely when their expertise is requested.’
Van Oord is not the first offshore and dredging contractor to opt for unmanned offshore survey vessels. Just last month, Jan De Nul ordered its first seagoing unmanned survey vessel with Maritime Robotics.