One of the world’s leading underwater vessel maintenance and repair service providers, SeaTec, is working on a number of initiatives which it believes will aid the drive towards decarbonisation within the shipping industry.
Among the most significant of these is its imminent launch of a new closed-circuit propeller polishing system which features technology that captures biofouling and metal particles and removes them safely to the surface for filtering, and which is now ready for deployment. Initially the company will utilise the system in the UK but expects eventually to roll out the technology worldwide.
Nick Laker, managing director of SeaTec, says: “Regular propeller polishing every three to four months easily pays for itself, yet it is quite normal for propellers not to be polished for two years or more. We want to encourage owners and managers to look again at their approach to this. There have been restrictions on underwater propeller polishing in some places because of environmental concerns, but our new closed-circuit system has the scope to enable this work to be carried out safely in even the most strictly regulated ports.”
Trials on the system were recently carried out on a managed passenger vessel. Following a propeller polish using the SeaTec closed-circuit system, the vessel saw a one knot increase in speed and a fuel saving of 2,111kg a day, equivalent to at least US$150,000 (£121,800) a year. Moreover, the operation reduced carbon emissions by around 750m3 a year.
Laker says: “On this basis the closed-circuit propeller polishing would pay for itself in just five days, while also having a major environmental impact. More regular polishing is we believe a highly effective way of achieving environmental objectives and should not be banned, but encouraged, when the technology is demonstrated to have environmental safeguards.”
Another important initiative also due to be rolled out shortly is the SeaTec Underwater Portal. The is a new data management system that enables fleet wide vessel data and reports to be uploaded to a central data base, allowing SeaTec engineers to track the vessels’ performance and service history, suggesting possible maintenance work and the ideal location to carry out such work.
Laker says: “The Portal will be a crucial tool allowing us to be more proactive in anticipating the work required to keep vessels operating in an environmentally and economically efficient way. It will allow us to harness the knowledge we have about our customers’ vessels to preempt problems and provide solutions.”
SeaTec reports a healthy volume of work worldwide over the past year for its underwater maintenance teams, with business spread fairly evenly between its dive stations in the UK, Rotterdam, Singapore and Chennai. Laker says: “We have seen an increase in fleet wide contracts, which is good news. As for the types of work we are being contracted to perform, there has been a notable increase in the requirement to carry out inspections of scrubber overboard discharge pipes which can get heavily fouled.”
In one recent notable maintenance project, SeaTec completed underwater rudder weld repairs on two container sister vessels at Rotterdam port. During routine underwater propeller polishing and hull inspection work, it was discovered that the vessel’s rudder bottom plate connection welds were both heavily impacted by cavitation and lamellar tearing over a length of up to 1576mm.
Jean-Paul Engels, general manager for SeaTec’s subsea operations, says: “We started putting together a repair plan which could be reviewed both by our clients and DNV prior to arrival of the vessels, allowing us to conduct the weld repairs in accordance with AWS D3.6M:2017 Class A welds. The repairs were completed on time and within the vessels’ berthing schedules thanks to the expertise and dedication of the SeaTec team and partners who attended the vessel in Rotterdam.”
