Disaster
However, in 1976 a completely unanticipated event occurred which almost caused the complete destruction of the clock. At 3:45am on the 5th of August 1976 as the clock started to chime, metal fatigue in the shaft connecting the chiming train to its fly fan caused the shaft to break. Without the retarding and braking effect of the fly, the chiming mechanism, propelled by the 1.25 ton weight in the shaft, increased its speed of rotation dramatically. This led to the total destruction of the chiming mechanism, with various components and fragments of others being scattered about the clockroom. Some pieces of machinery were flung at the ceiling with sufficient force to penetrate to the room above. The cast iron frame was fractured and collapsed onto the winding motor below. The flying debris also caused damage to the going and striking trains.