Automatic performance reporting enables crew transfer vessel operators to increase performance and efficiency, reduce downtime, enhance safety and save their clients money
A crew transfer vessel (CTV) plays a particularly important role in the offshore wind industry. Without windfarm technicians, turbines cannot be maintained or repaired when required, and with a CTV sometimes transferring personnel to and from tens of turbines in a single voyage small gains in efficiency quickly add up. But with windfarms being built further and further offshore, in ever more challenging conditions, ensuring turbine technicians arrive ready to work, in good health and well rested is essential.
Multiply efficiency gains in performance by the number of CTVs in a fleet of vessels, and the number of well-rested technicians on those vessels and significant operational efficiencies accrue. However, manually logging data on every aspect of a voyage would not be cost-effective, hence the growing uptake of a new generation of monitoring systems that automatically gather engine, navigational, motion and health data, including fuel efficiency, CO2 emissions, heave motions, tower impact and push-on force, even indications of motion sickness.
Among them is BareFLEET, a vessel monitoring system developed by Reygar in the UK. As well as saving customers money by helping to improve efficiency, BareFLEET allows operators to demonstrate they are meeting contractual obligations, while taking care of personnel on board. It does this automatically, leaving skippers free to concentrate on operating the vessel.
The system is capable of generating top-line reports for the boardroom, presenting trends in overall fleet utility, performance and health aggregated over weeks or months. Particularly useful for fleet operational and maintenance managers, BareFLEET can issue daily or weekly vessel and fleet reports.
These reports provide a comprehensive but concise single page overview of vessels’ track, fuel efficiency, motion and impact, plus machinery health and weather conditions. The live status of vessels can also be viewed via a web portal.
The information behind these reports means engineers and OEMs can drill down into a high level of detail for diagnostic, verification or warranty claim purposes. The system can also connect to third-party planned maintenance systems. Using GSM communications keeps operating costs low as all data is stored on board the vessel until a connection becomes available, although satellite communications can also be used. The information is presented in a clear and simple way, whether it is highly detailed diagnostic and performance data for engineers or straightforward, easy to understand key performance indicators across an entire fleet.
As Reygar managing director Chris Huxley-Reynard explained, the system was developed to provide clear, simple, daily reporting, summarising all the information an owner needs. The information is emailed to the user and includes data such as fuel savings in the form of presentations of fuel efficiency versus speed curves.
Importantly, given that CTVs transport personnel who are on their way to work in a challenging environment, BareFLEET can also provide evidence that passenger ride comfort is being monitored in accordance with ISO 2631-1.
It provides a log of each turbine transfer, including vessel motion and tower push-on force, and full details of fuel burn and CO2 emissions. This provides owners on shore with improved situational awareness of fleet activity and health issues and early warning of problems before problems occur. For the big picture the system also generates high-level management reports presenting trends in overall fleet utilisation, performance and health, aggregated over weeks or months.
Mr Huxley-Reynard told OWJ that a growing number of users in the offshore wind industry have adopted BareFLEET, including CWind, part of Global Marine Group, which is fitting it on all of its CTVs.
“We need to provide fast, reliable workboats that deliver crew feeling fresh and ready to work,” said CWind’s head of CTV fleet, Josh Brennan. “It’s also important to address any potential problems with our vessels before they arise and avoid downtime wherever possible.
“The system allows us to get a full understanding of fleet use, needs and operating level and an insight into vessel performance history, all of which allows for instant investigation of any potential issues before they become a problem. We also pride ourselves on operating a fuel-efficient CTV fleet and BareFLEET helps us to monitor our CO2 emissions, which in turn allows us to drive costs down for clients.”
Mr Huxley-Reynard said the size of CWind’s fleet has made BareFLEET especially useful to it. “Getting information on potential machinery issues every day direct to decision makers, has helped minimise the time taken to identify and rectify problems,” he explained. “This has reduced vessel downtime and helped them use their staff resources more efficiently. Another advantage for them is that BareFLEET works with any main engine or generator equipment. As some of their boats have different engines, they’re able to use one system to manage fleet-wide maintenance.”
CTV management company Richardson Marine fleet superintendent, Stuart Richardson said technology such as BareFLEET makes it possible to detect potential problems before they become an issue.
“We initially used BareFLEET to monitor drive bearing temperature and vibration, which gives us early warning of any issues with the health of the vessels,” he explained. “Having a live monitoring facility has meant we can plan inspection and maintenance, fixing any problems before they lead to downtime. It enables me to keep an eye on what’s going on with a vessel without having to be on board.”
He explained that in instances where maintenance or repair work has been needed, the information gathered by BareFLEET has enabled a quick full fault diagnosis.
“Automatic reporting allows the crew on CTVs to concentrate on transferring people rather than keeping detailed logs,” he said. “With as many as 20 transfers taking place in one day, it can make a real difference to overall efficiency and, of course, safety and the fuel graphs generated by the system help us to reduce the fleet’s fuel bill. Ultimately, that also benefits our customers, the developer or owner of the windfarm. Windfarm operators are really focusing on fuel savings, so it’s good to have a picture of how much you’re using and whether taking a different route can save fuel. That gives us an edge – we can help them save money and we can reduce our own carbon footprint by taking the most economical route once in a windfarm.”
DP system was designed for small vessels
Tests of a simple and robust dynamic positioning (DP) system Reygar developed for challenging applications in the offshore renewables sector have ‘surpassed expectations.’
Reygar tested its StemTIDE DP control system on a 60 m x 22 m multi-purpose barge Mormaen 15 as part of a project backed by Innovate UK. The Keynvor Morlift Ltd (KML)-owned barge was converted with StemTIDE and two 430 kW modular azimuthing thrusters.
StemTIDE allows a vessel with two or more directional thrusters to hold position or accurately manoeuvre under automatic or joystick assisted control. The system also allows subsea vehicles such as ROV’s to be automatically followed for survey type work and can work with conventional azimuthing thrusters, waterjets and even fixed main drives with bow and stern thrusters.
During the trials, the system was tested in several modes of operation and consistently held the barge in position to within +/-0.5 m and heading to within +/-1.0 degree of the target in 15 knot winds. Performance of the system was also verified for operation in tidal current conditions, with opportunities for further enhancements identified for the future.
KML believes that adding DP capability to the barge makes it suitable for a wide range of operations, nearshore and offshore, including cable lay, wave and tidal energy installations, offshore wind construction and operations and maintenance.