The energy technology provider has taken an industry lead by implementing the Dynamic Positioning Digital Survey(DPDS) system, developed by Kongsberg Maritime, for annual trials on board its construction support vessel Deep Star. These trials are required to verify the integrity of the dynamic positioning(DP) system, which is used by the vessel for accurate manoeuvring, station- and track-keeping in pipe-laying and installation of subsea structures.

Stringent regulatory requirements for DP systems

The trial for the Deep Star entailed a wide-ranging test programme comprising around 95 tests of multiple mechanical systems associated with dynamic positioning – including propellers, thrusters and power distribution systems – to comply with stringent regulatory requirements for operations.
This has typically required an independent class surveyor and/or third-party DP FMEA consultant to be brought onto a vessel, spending several days carrying out detailed inspections and manual tests of the various DP-related systems to tick the boxes on test documentation running into hundreds of pages.
TechnipFMC’s Senior Manager of Innovation for OneFleet, Pawel Panka, says 'the approvals process has completely changed’ with the adoption of DPDS as a digital survey application. “We have implemented the system fleet-wide as part of our Digital Vessel project as we aim to digitalize our offshore fleet in line with the onshore environment,” he points out.

DP verification process moves onshore

“The biggest difference to traditional trials is that the tests are completed incrementally and that verification has moved from offshore to onshore,” Panka summarizes.
"The methodology of data-driven verification(DDV) is to automatically gather test data generated by the DP system to provide an accurate body of evidence for verification that can then be analysed and assessed remotely by a surveyor working onshore," he explains.

Remote access to verification data

The vessel crew can now run test activities and mark the completed steps within the DPDS. Both the crew and onshore surveyor are required to undergo training in using the DPDS as a requirement from DNV.
Data on the vessel’s behaviour that is automatically harvested during the test programme is then remotely accessed by the surveyor onshore and assessed for verification using a digital playback application.
“The DDV methodology offers full transparency, bolsters crew competence and improves the efficiency of operations,” Panka emphasizes.

More flexibility and less vessel downtime

"As well as gaining competence in test execution, the crew is given more flexibility as tests can be performed during vessel standby periods across a wider time frame, rather than being scheduled within a fixed period of around three days under the traditional method,” he explains.
This contributes to reduced vessel downtime and thus enhances the cost-efficiency of operations for the client, while also cutting fuel consumption from trials. Furthermore, there is no need to transport a surveyor to and from the vessel, which minimizes associated costs and has a further positive impact on TechnipFMC’s carbon footprint, according to Panka.

Sustainability and reduced costs are software drivers

Kongsberg Maritime’s Product Advisor for Digital Oil and Gas Applications/Ship Intelligence, Amir Klepper Zanganeh, says, "Sustainability, cost reduction and providing full transparency of DP operational data were among the rationale for development of the DPDS."
The software harnesses stored data that is continually generated by the DP system and depicts it in a way that gives a visual representation of operational performance accessible to stakeholders.
“The Dynamic Positioning Digital Survey system is able to systematize this data, which is a true record of what is happening on board, and present it in a logical manner for the purpose of verification. It is therefore important to gather relevant data for each specific test and wrap it all together for efficient verification,” he says.

Strict criteria for secure data gathering

The system is required to generate a data-based body of evidence that is tamper-proof, which means the crew should not be able to alter or filter data that is transmitted via the cloud to the onshore surveyor, and all test results – both positive and negative – should be accessible.
Data coverage and the quality and reliability of this data are therefore key factors, along with cyber security, according to Aleks Karlsen, DNV Senior Principal Specialist for DP Systems Maritime. “Data gathering has to be time-synchronized and also highly specific for each system tested, as well as efficient and fail-safe for application across multiple vessels,” he says.
The DDV class notation sets the requirements for the gathering, treatment and delivery of collected data to ensure the quality of this data for use in a class assessment, while also incorporating demands for cyber security. It covers several different verification methods, including self-verifying systems and digital twins, in addition to the digital survey application.

Improvements in failure diagnostic

A further beneficial spin-off of the DPDS is that visualization of historical operating data with the DP system makes it easier to backtrack and diagnose the cause of any failure. That can reduce the time required for investigation and repairs from days to hours, as well as the time lag for verification of such repairs, according to Panka.
Karlsen says though that there is a risk of “drowning in data”, which can lead to time-consuming and prohibitively costly class assessments; project partners have spent much time and effort in fine-tuning the test programmes and DPDS to filter through the most relevant data points for each test.

Flexibility on survey work

According to Karlsen, DDV gives more flexibility to the surveyor in carrying out assessments and reduces time wasted in transit. Digital surveys are therefore a building block for autonomous shipping.
But he adds that there is a need for raised surveyor competence in understanding and interpreting digital test results without the benefit of physical checks to gain familiarity with the vessel. Furthermore, there is a heightened requirement for crew training to ensure correct data inputs, which is also covered by the DDV notation. 
Panka says traditional test programmes have been adapted for a digital interface to make them compatible with data-driven verification. Robust internet connectivity is an important factor to enable remote access to the DPDS while the vessel is in DP mode, rather than having to wait until the vessel is in transit or in port.

Fleet-wide implementation of the DPDS

Zanganeh says, "The system remains under continual improvement based on feedback from TechnipFMC, which is a leading technology provider to the traditional and new energies industries, as well as input from DNV." He adds, "The system has evolved a long way since the initial version was installed as teething troubles have gradually been ironed out over a long period of refinement."
The DPDS, which has also gained approval in principle under the DDV notation, has already been implemented on another three vessels in the TechnipFMC fleet pending class approval, with a further four vessels due for acceptance testing early next year. 
TechnipFMC now aims to have all of its own vessels DDV-compliant by mid 2023, according to Panka.

■ Source: www.dnv.com