Lloyd's Register, the world leader in the classification of LNG carriers, has published a new guidance document for the design of membrane-technology liquid natural gas containment systems. The document is aimed at improving design procedures with respect to sloshing forces, and is the result of a long program of research and development, including extensive consultation with industry, and an investment of over $1,1m. The document has been used as part of the appraisal process for the approval of the largest LNG carrier built to date – the Q-Max type ships, of which Lloyd’s Register is the lead class. Sloshing is the motion of a fluid in a partially filled tank which may in sometimes be violent.