Classification society ClassNK and Panama's Maritime Authority have granted approval in principle (AiP) to SRC for its Methanol Superstorage tank design, which the company claims can almost double shipboard storage capacity for methanol and ethanol.

The approvals confirm that the tank concept is feasible for its intended application according to ClassNK's guidelines for ships using methyl and ethyl alcohol as fuels.

The technology uses a Sandwich Plate System (SPS) featuring a solid elastomer core between two steel plates that is 25 millimeters thick. This contrasts with traditional fuel tanks where internal and external walls are separated by a cofferdam of at least 600 millimeters.

SRC claims 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 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, with final approval resting with the flag state. To reflect this, Panama's expertise was brought into the review, which led to the country also granting AiP to the technology.

For final approval of an actual fuel tank design applied to a specific ship, complete documentation covering design details would require full approval according to relevant regulations, rules, and guidelines.

An AiP is issued at the initial design stage as proof of conformity with requirements before a specific target ship is decided. It aims to prevent regulatory rework in later processes and shorten examination time during class registration.

"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."

SRC Group, founded in 2001, offers engineering, procurement, construction, and installation solutions for marine and offshore projects. The company has offices in Estonia, Italy, Norway, the US, Singapore, and the Netherlands.