Cruise ship owner partners with LNG cryogenic equipment designers and engineers to develop a flexible pipe-based refuelling solution
Cruise lines have invested billions of dollars in 26 LNG-fuelled cruise ships, representing about 44% of new capacity. One of the cruise lines betting on LNG is MSC, which is spending around US$6Bn on five LNG-fuelled World-class cruise ships, the first of which will be delivered in 2022. Each of the 6,762-passenger cruise ships will also integrate a new fuel-cell technology demonstrator onboard. This demonstrator, with an output power of 50 KW, will produce electricity and heat using LNG.
While burning LNG as a fuel offers an opportunity for cruise shipping to cut greenhouse gas emissions, it also presents a number of challenges, chief among which is conducting refuelling operations with thousands of passengers onboard.
Recognising this, MSC Cruises partnered with cryogenic coupling and valve manufacturer Arta GmbH in 2017 to develop a double-barrier safety system specially designed for refuelling LNG-powered cruise ships.
To augment its own experience, Arta teamed with Brugg, a long-time manufacturer of stainless-steel flexible piping. Additionally, UK-based marine and oil and gas design and engineering firm Houlder Ltd, supported the effort, focusing on transfer system conceptual design and detailed engineering.
Safe handling of the LNG was a primary concern of the partners. Arta LNG project manager Christian Satorius explained that bunkering LNG is far different than bunkering heavy fuel or marine gasoil: “The bar has to be raised in terms of safety. There cannot be any leakage.”
“The bar has to be raised in terms of safety”
Brugg Rohrsysteme GmbH head of product management Meik Schubert, said: “If you want to reduce the safety zone around your bunker port then a double-barrier system is a safer option.”
Key components of the LNG bunkering solution are an emergency breakaway system, QCDC coupling and decoupling mechanism and a double-walled, stainless-steel flexible pipe.
Using the new double-walled barrier system from a bunker vessel, MSC Cruises is expected to be able to limit the size of the required safety zone, optimise the speed of bunkering and minimise the impact on passenger activity and cabin space.
The system’s double wall and complete vacuum insulation act as additional layers of protection, ensuring the safe handling of the cryogenic liquid at -162°C throughout the entire process. Additionally, QCDC couplings incorporate double-sealing technology.
Houlder Ltd senior structural engineer James Smith explained that a passive hydraulic handling system is being used in the connection pipe to support and protect it during ship-to-ship (STS) bunkering operations.
Both Mr Satorius and Mr Schubert noted that integral to safety will be the proper training of both the crew of the bunker vessel and cruise ship in handling the system.
Besides cruise ships, Mr Smith pointed out that the system would also be suitable for applications with LNG-fuelled ferries, floating storage units and floating storage and regasificiation units.
“The opportunities and scope of this flexible and simple system will grow and grow,” he said.
Mr Satorius said that two systems could initially be deployed on LNG bunker vessels, perhaps one on the port and another on the starboard side, to allow for flexible refuelling. He also sees the potential for ship-to-shore bunkering. Mr Satorius expects the first systems will be deployed in the Mediterranean, Scandinavia and the US.
The partners are working with class societies Bureau Veritas and DNV GL, finalising approvals and assessing functionality and risks, with plans for the system to undergo ‘live’ trials in H2 2020.