On 12 April 1918 five Zeppelin airships flew over the east coast of England. This 300kg bomb was dropped over South Lincolnshire during this raid. A plaque later added to the bomb explains that it was prevented from detonating 'only by one thread'.

The inscription reads: 'Cause of failure- Slight obstruction on threads of vane-rod causing the guide pins to shear and in consequence the needle pellet was not quite free to come forward. On detonator when found the fuze was kept from going off only by one thread'.