An INERT ‘Butterfly Bomb’ or Sprengbombe Dickwandig 2 kg or SD 2.

The INERT ‘butterfly bomb’ in the photograph has a type 41A fuze with ‘Zeit’ and ‘AZ’ settings. It belongs to the private collection of Graham Cooper (Lincolnshire). The wings are original and the bomb part is a resin copy.

In the early hours of Monday 14th June 1943, the Luftwaffe dropped around 3,000 ‘butterfly bombs’ on Grimsby and Cleethorpes. Over 100 people were killed and hundreds were injured. In an attempt to keep the enemy unaware of the success of this new type of anti-personnel device, to lower the chances of repeat attacks elsewhere, reporting restrictions were applied. To this day, the story of the chaos and destruction in the Grimsby area is not well-known outside Lincolnshire.

The ‘butterfly bomb’ or Sprengbombe Dickwandig 2 kg or SD 2 was a German 2 kilogram anti-personnel submunition used by the Luftwaffe during the Second World War. These devices were released from containers in groups. As they fell to the ground, the side wings delayed the descent and the angled end wings turned the ‘Butterfly’ and spindle which armed the fuze. The various fuzes and fuze settings could trigger the explosion upon impact or after a set time. The interesting appearance of the ‘butterfly bombs’ contributed to their danger. The people of Grimsby and Cleethorpes had to be quickly educated as to the highly sensitive ‘booby-trap’ characteristics of unexploded versions. The US military was so impressed by the SD 2 that they manufactured an almost exact copy for use during World War II, the Korean War and Vietnam War, designating it the M83 submunition.