All systems of law provide limitation periods during which civil claims must be commenced. These are known as time bars and are designed to prevent a defendant being faced with a claim many years after the event when witnesses may have disappeared or forgotten about the incident or the documents may have been destroyed. The claimant must ensure that his claim is brought within the specified period, otherwise his claim will be time-barred. These are essentially two types of time bar; those which apply generally and are governed by statute and those which apply to specific claims. General time bars are governed in England by the Limitation Act 1980 which lays down the limit within which claims must be brought. Section 5 provides that claims relating to contract must be brought within six years of breach. This limit would be applicable to ordinary charter party claims that is those which are not covered by any specific time bar. Section 2 provides that claims in tort, for example negligence causing damage to property must be brought within six years of the date on which the cause of action occurred or, in the case of personal injury or defamation (libel or slander) within three years from the moment that the plaintiff knew or ought to have known of the damage. The six years time limit starts counting from the date on which the physical damage occurred. Sections 11 and 12 provide that claims in respect of personal injury must be brought within three years although the court has a wide discretion of extend this period if such a limitation operates inequitably. A person injured on a vessel has three years in which to bring a claim against the vessel. The Limitation Act, 1980 does not apply to Admiralty Actions in rem. The expression in rem means actions against a thing, typically a ship as opposed to actions in personam (against a person). Actions in rem must be brought under the Maritime Conventions Act 1911.