Condition assessment scheme

The Condition Assessment Scheme, CAS, is a mandatory structural survey regime for ageing single-hull oil tankers, set by MARPOL Annex I Regulations 20.6, 20.7 and 21.6.1 and detailed in IMO resolution MEPC.94(46). It applies to Category 2 and Category 3 single-hull tankers, which must pass CAS by 15 years of age or by the first intermediate or renewal survey due after 5 April 2005, whichever is later, to keep trading toward their phase-out date. The survey covers the hull structure in way of cargo tanks, pump rooms, cofferdams, pipe tunnels, void spaces in the cargo area, and all ballast tanks, with close-up examination and thickness measurement. A failed CAS bars continued operation.