ABS, a leading provider of classification services to the global marine and offshore industries, has granted Approval in Principle (AIP) to Troy, Mich., based Altair for the Cubic Donut Tank System (CDTS) LNG containment concept.
The CDTS concept is adapted from a patent first filed nearly 40 years ago. The principle behind the initial design concept is the construction of a near prismatic shape using 12 interconnected cylinders to create the structural efficiency of a spherical tank and the volumetric efficiency of a membrane tank.
“ABS continues to review innovative LNG designs, drawing on 50 years of experience in the safe handling, storage and transport of gas,” says ABS Chairman, President and CEO Christopher J. Wiernicki. “As designers apply new solutions to gas carrier challenges, ABS will support this process with approvals that enable LNG shipping to move forward in safety.”
According to Altair ProductDesign, the CDTS retains the advantages of the original concept, including greater relative cargo capacity than either a spherical or membrane containment system, which enables a vessel with a shorter length but comparable draft for the same deadweight. Altair designers say the CDTS is suitable for operations in heavy sea states at any fill level, and its lower profile compared to spherical tanks for the same cargo volume reduces hydrostatic loading.
ABS has completed more than a dozen assessments on new concepts in gas containment in recent years as demand for LNG evolves into small-scale trades, alongside intermediate and large gas carrier concepts.
A pioneer in the safe transport and handling of gas, ABS classed the world’s first LNG carrier, the “Methane Pioneer”, in 1959 and has extensive experience with the full scope of gas-related assets, including the largest LNG carriers in service. In 2013 ABS formed the Global Gas Solutions Team in response to the rapid escalation in the number of gas-related projects, including LNG and LPG transportation and the growing use of LNG and LPG as fuels.