Partial inefficiency can have the same effect as total inefficiency. A good illustrative example of this is The H.R. Macmillan (1974). What happens when one crane breaks down and the other two remaining workable are able to do all the work required? There would have to be an assessment of the time actually lost and the test would have to be “how much earlier would the vessel have been away from her port of loading or discharge if three cranes, instead of two, had been available throughout?” The burden of showing that the clause validly applies to circumstances is on the charterer. The clause is for his benefit and he must show that the events fall within its wording. The right to “off-hire” does not affect a charterer’s right to damages for breach of contract. The two rights are separate and unrelated. In The Ira (1995) there was an agreement between the parties that after discharge of cargo at Ravenna the vessel would be dry-docked (at Piraeus). Dry-docking was completed on 24 January 1992 and the owners offered the ship back to charterers on dropping off the pilot off Piraeus at noon the next day. The charterers argued that the time actually lost to them was from dropping off the pilot off Ravenna. The owners said the voyage Ravenna/Piraeus was not time lost to the charterers because her next engagement was loading in the Black Sea and a deviation to Piraeus after leaving Ravenna was only a slight geographical deviation off that route. The arbitrator favoured the owners’ argument. On appeal by the charterers, the Court upheld the arbitrator and said that the burden was upon the charterer to prove the off-hire event and its causative effect, and to prove that thereby he had actually lost time (not merely a paper loss). It was not simply a matter of showing an off-hire event and its duration and complaining that the time was automatically lost therefrom.