Cold lay-up

Cold lay-up is the long-term idling of a ship with the main and most auxiliary machinery shut down and a skeleton crew or none aboard. It applies when a vessel is expected to be out of trade for many months: the engine room is preserved, tanks are cleaned or inerted, dehumidification protects machinery and accommodation, and only emergency fire and flooding cover stays active. Class status is usually suspended or laid-up by agreement with the society, with a reactivation survey before return to service. Cold lay-up cuts daily cost to the minimum but raises reactivation expense and corrosion risk, unlike warm lay-up where systems keep running.