Classification societies are supporting owners to accurately measure bollard pull, assess new markets and prepare for the energy transition
New research into accurately measuring bollard pull will help ensure the safe operation of tugs, supporting the industry as new opportunities open up in the floating offshore wind market.
Bureau Veritas (BV) Marine & Offshore global market leader for tugs and offshore support vessels Eva Peno says knowing thebollard pull capabilities of tugboats will reduce the risk of maritime and offshore accidents.
Although bollard pull is estimated by designers, the only way to achieve true accuracy is from trials, she says. “Bollard pull measurement is a simple but vital assessment for the safety of anchor-handling vessels and tugs, because an over-estimated bollard pull could give rise to serious accidents during operations,” she tells Riviera Maritime Media.
To improve accuracy and ensure consistency in these tests, BV and 31 stakeholders, including shipowners, designers, shipyards and engine manufacturers, undertook a three-year joint industry project (JIP) led by Marin to develop a new standard for measuring bollard pull.
As a result of this cross-industry collaboration, a new measurement standard was developed and has been implemented in BV rules since June 2021.
“The standard aims to raise awareness, avoid ambiguous definitions, and harmonise testing procedures to ensure accuracy and consistency,” says Ms Peno.
It clarifies the interpretation of “maximum engine power used for these tests, distinguishing between the maximum design power and levels that can be temporarily achieved beyond this,” she explains.
“The new standard also accounts for other environmental factors that can influence the test result, setting limits for variables such as water depth, currents and winds, for the test result to be valid.”
Marin’s research indicates the alignment and calibration of the load cell used to measure tension on the line can have a major effect, creating variability of up to 7%.
The JIP outlines appropriate trial procedures to ensure the tests are standardised and considers new power generation technologies such as electric-hybrid systems.
“Greener tugs will support the energy transition,” says Ms Peno. Operators are installing low-emissions propulsion systems on new tugs, and some are considering retrofitting existing vessels.
Oceangoing tugboats are already being employed to assist in offshore windfarm projects. Ms Peno expects anchor-handling vessels and tugs to be deployed to install floating offshore windfarms (FOWF), opening new opportunities for this type of fleet.
“Anchor-handling vessels and tugs can be used to install mooring lines and anchors, tow floating structures, and help to install cables,” she says.
“In this role, a tug and anchor handler’s bollard pull is a key consideration for FOWF developers when chartering vessels to work on their project.”
While the growing number of floating offshore wind projects is cause for optimism for anchor-handling vessel and tug owners, they may have to upgrade their vessels to meet the stricter sustainability standards being set by the industry.
“Batteries are a particularly attractive option for these vessels, which generally only need full power 15-20% of their operating time,” says Ms Peno.
She sees growing interest in battery and electric solutions in the tugboat sector. “At BV, we are proud to support industry pioneers, using our expertise and independent perspective to validate new technologies and mitigate risk,” she says.
“Our design review allows us to assess a range of innovative equipment, including environmentally friendly fuel systems that enable faster, safer work, and batteries that allow for increased installed power and bollard pull.”
BV supports tug owners with extensive knowledge of alternative fuels, electrification and the offshore wind industry. “We are ready to support owners as they prepare for the future,” says Ms Peno.
In one of these initiatives, BV is working with Aras to develop and deploy digital twin technologies for vessel design classification approvals. This will enable BV to collaborate with naval architects and improve real-time access to vessel data.
This digital twin will be a foundation to further develop data services to improve safety, operational and environmental performance.
BV’s digital classification strategy includes moving from reviewing 2D plans for classification to a collaborative design review on a unique 3D model. It also includes remote and augmented surveys and remote inspection techniques, such as aerial drones, and using data for condition-based monitoring and maintenance.
Enabling alternative fuels
Lloyd’s Register is helping port operators and tug owners to develop methods for using alternative fuels to diesel. It is working with technology developer CMB.Tech and the Port of Antwerp-Bruges to introduce a hydrogen-powered tugboat.
CMB.Tech is implementing the first hydrogen-powered tugboat, Hydrotug 1, which is scheduled to enter service 2023 in Antwerp. It collaborated with Anglo Belgian Corp on the propulsion system and the engines. Hydrotug 1 has two BeHydro V12-cylinder, dual-fuel, medium-speed engines that can run on hydrogen and diesel.
Lloyd’s Register verified the technology on board Hydrotug 1, says CMB.Tech chief technology officer Roy Campe.
“Port of Antwerp-Bruges will be the first user of Hydrotug 1, the world’s largest hydrogen-powered vessel,” he says. “The technology has been approved by Lloyd’s Register and we are ready to approach the global market. With this technology, we can significantly improve the air quality in ports and bring hydrogen technology to every port worldwide,” Mr Campe adds.
Hydrotug 1 is the first vessel to be powered by BeHydro dual-fuel, medium-speed engines, with each providing 2 MW of power, and exhaust aftertreatment to comply with the latest EU Stage V emissions requirements.
The engines passed factory acceptance tests that validate the correct operation of the equipment, witnessed by Lloyd’s Register.
Armón Shipyards in Navia, Spain is building Hydrotug 1, which was launched 16 May. Extensive testing and sea trials will follow, with delivery planned December 2022 and full operations Q1 2023.
Italian class society RINA and vessel builder Fincantieri signed an agreement Q2 2022 to collaborate on developing technologies for decarbonisation, including alternative fuels, carbon capture and renewable energies.
It is working on approvals in principle for these technologies, simulating new fuels and energy vectors and a risk-based approach to classification. Fincantieri builds articulated tug-barge units in North America, including those used for LNG fuel bunkering.
Korean Register (KR) has published guidelines on the metal materials suitable for use in storage tanks for green fuels, such as LNG, ammonia, methanol and hydrogen.
Guidelines for Selection of Metallic Materials of Containment Systems for Alternative Fuels for Ships includes detailed technical information on all the metal materials suitable for such containment systems.
It was jointly developed by KR’s research division and the Korea Institute of Machinery and Materials. KR proposed suitable metal materials for use in fuel containment and the supporting structures, considering the characteristics of the various eco-friendly alternative fuels. Applicability evaluation methods and procedures are also included in the guidelines.
KR included restrictions and technical limitations affecting metal materials used to contain liquid hydrogen, which is technically the most difficult to store in large capacities and hardly used for vessels as gaseous hydrogen damages materials.
ABS handed out its first autonomous and remote-control navigation notations to Keppel Smit Towage’s Maju 510 tug April 2022, after trials of the Keppel Offshore & Marine (O&M) and ABB technology.
Maju 510 is capable of autonomous navigation, collision detection and avoidance and can be remotely controlled from shore. Keppel Marine and Deepwater Technology set up the shore command centre, Keppel O&M upgraded Maju 510 by retrofitting advanced systems to generate digital situational awareness and high accuracy positioning and manoeuvring, including ABB Ability marine pilot vision and marine pilot control. This was all verified by ABS.
