Boilers, pressure vessels, cranes, lifts and other lifting equipment, engines, electrical equipment may be insured against breakdown under the engineering policy. Breakdown generally means the breaking or burning of any part of the plant while it is running that causes a sudden stoppage that necessitates repair before resuming work although there may be specific definitions for particular forms of plant. Basic breakdown cover relates to self-damage, but cover is usually extended to damage to surrounding property, public liability, fragmentation, consequential loss, hired-in plant damage and deterioration of stock.