A new design concept aims to cut the costs and speed to market of small to mid-scale LNG imports, exports and bunker supply services
UK-based engineering and design firm Houlder has designed a no-jetty concept for LNG transfers and bunkering for small to mid-scale import projects where having a fixed jetty would be impractical, expensive or harmful to the environment.
Houlder’s floating transfer terminal (FTT) is a compact barge that uses an LNG-transfer system developed with KLAW LNG to connect to a carrier. It also employs Trelleborg Cryoline cryogenic floating hoses to connect to shore.
Demand for LNG is growing in coastal communities around the world, and particularly in island nations such as Indonesia and the Caribbean states. However, these countries may struggle to build shore-based terminals, due to high land prices, constraints on space, shortage of funds or ecological sensitivities.
Houlder worked with Trelleborg and Wärtsilä to develop the FTT as a cost-effective solution to these constraints.
The system supports imports, exports and bunker-supply needs, transferring cargo between ships moored up to 800 m off shore and land-based units. It requires no major civil works, and when the contract ends, the units can move to other locations.
The FTT barge has its own propulsion, a simple, efficient steel or concrete structure and space on deck to operate the LNG equipment safely. Houlder can tailor the designs to detailed engineering specifications, local building capabilities and client preference and can scale up or down with hose sizes between 6 in and 20 in, a range with a corresponding transfer rate of 1,000mᶾ/hr-5,000mᶾ/hr.
Trelleborg’s Cryoline floating hoses will transfer LNG and boil-off gas between shore and barge. The hoses bolt together in 12m sections in the required string length, to transfer LNG offshore safely, minimising boil-off rates. Houlder says the hoses combine flexibility, reliability and a long service life and deliver what the client needs, in terms of safety, flow-rate and operating requirements.
Houlder worked with KLAW to develop the Khobra transfer systems that deliver the LNG between vessels in a safe, controlled way. Khobra comprises a deployment crane, a motion-compensated deployable emergency-release system (ERS) manifold and a gas system. Its features include:
- A standard marine knuckle-boom crane
- Flexible LNG transfer and/or vapour-return lines, both 4 in and 8 in
- Active ERS and shut-down systems
- Quick connection and disconnection
- Ease of alignment to different manifold arrangements
- Monitoring of vessel motion and compensation for it, including the use of a limit-detection system
- A secure landing frame to transfer loads
- Proven gas-handling components.
Houlder says the FTT concept also minimises the number of crew required for transfers and LNG-bunkering. The concept has a lead time of 12-18 months, based on local steel or concrete fabrication. Project manager Gianpaolo Benedetti estimates that the capital costs are 30%-50% less than those for a land-based jetty.
“The FTT is a flexible, quickly deployable solution that, thanks to a low-draft barge and floating hoses, can operate in the widest range of locations, at a fraction of the cost of fixed infrastructure,” says Houlder director ship design and engineering Jonathan Strachan. “Houlder and partners are discussing a range of applications in the Americas and Asia.”
Houlder is promoting LNG as marine fuel as a cornerstone of its business-development plan. In February, Houlder signed a memorandum of understanding with KLAW to develop bunker and transfer solutions for small to mid-sized LNG projects.
The company has restructured and, in September, appointed former Rigmar chief operating officer Neil Ferguson as director of LNG storage and distribution to drive Houlder’s end-to-end LNG projects.