Nippon Kaiji Kyokai (ClassNK) has granted approval in principle (AiP) to SRC for Methanol Superstorage, the innovative tank design concept that uses a Sandwich Plate System (SPS) technology to almost double shipboard storage capacity for both methanol and ethanol.
The ClassNK AiP confirms that Methanol Superstorage is feasible for the intended application in accordance with the Society’s 'Guidelines for Ships Using Alternative Fuels, Part A: Guidelines for Ships Using Methyl/Ethyl Alcohol as Fuels (Edition 3.0.0)'.
In contrast to traditional fuel tanks, where internal and external walls are separated by a cofferdam of at least 600 mm, Methanol Superstorage features SPS technology - a solid elastomer core ‘sandwiched’ between two steel plates that is 25-millimetre-thick. The solution delivers 85% more storage capacity than a conventional tank.
“With many methanol-ready ships now in operation, under construction or on order and ethanol also gaining traction, fuel storage has become an area of intense industry interest,” said Mr Ryohei Sakai, Manager (Project Hull), Technical Solution Department, ClassNK. “Because of its low volumetric energy density compared to HFO, a methanol tank would need to hold over twice the volume to generate the same energy, for example. This has consequences for ship range and design. SRC’s methanol fuel tank concept represents an approach to addressing this challenge.”
Methanol-fuelled vessels must follow the alternative design process, in which the final approval rests with the flag state. To reflect this, Panama’s expertise was brought into the review, with Panama also granting AiP to Methanol Superstorage. For final approval of an actual fuel tank design applied to a specified ship, a complete set of documentation covering design details would need full approval in accordance with relevant Regulations, Rules and Guidelines.
At the initial stage of designing or before the specific target ship to be implemented is decided, the design is examined based on the existing regulations such as international conventions and ship classification rules, and an Approval in Principle (AiP) is issued as proof of conformity with requirements. It also prevents rework of regulatory aspects in the post-process, shortens the examination time at the time of class registration, and can be used as a technical basis for external appeal of the design status.
Left to Right: Ryohei Sakai (Project Hull), Technical Solution Department, ClassNK, Alex Vainokivi, Innovation Manager, SRC Group and Ginette Sophia Testa Barnett, Ambassador and Permanent Representative of Panama to the IMO
“Receiving Approval in Principle for Methanol Superstorage from both ClassNK and Panama Maritime Authority represents a major step forward for SRC in our mission to achieve widespread industry acceptance for the solution,” commented Alex Vainokivi, Innovation Manager, SRC Group. “A Methanol Superstorage tank delivers almost twice the fuel storage volume of a traditional tank, while the SPS provides a triple barrier for fire protection, leak prevention and higher impact protection. It can also be retrofitted with minimal impact on the vessel’s general arrangement.”
