A yellow Butterfly Bomb – not used on Grimsby (see description).
The butterfly bombs dropped on Grimsby and Cleethorpes during the night of 13/14 June 1943 were overwhelmingly painted field grey, a distinctive grey-green colour commonly used on German ordnance. The only SD2 fuze types known to have been used in the United Kingdom were the Type 41, Type 67 and Type 70B, all three of which were dropped on Grimsby, Cleethorpes and Great Coates. (The Type 70A fuze was not used in the UK.)
The yellow-painted SD2 shown here represents a recognised wartime colour variation. Examples of yellow-painted butterfly bombs are known from elsewhere in Britain, including Kent, but there is no evidence that fully yellow-painted SD2s were dropped during the Grimsby raid. At least one bomb recovered from the Grimsby area carried red and yellow recognition stripes, demonstrating that striped variants were present among the predominantly field-grey weapons used against the town. It is possible that such bombs originated from stocks originally intended for use outside the United Kingdom, although this remains unproven.
The reason for the introduction of yellow-painted and striped SD2s remains a subject of debate. One long-standing theory suggests that yellow-painted bombs were intended for use over ripe cornfields or other light-coloured agricultural terrain, where the yellow finish would provide camouflage and make unexploded bombs more difficult to detect. However, German documents indicate that the yellow paint and markings were introduced to make unexploded bombs easier to see and avoid, particularly after German troops suffered casualties from their own unexploded SD2s during the campaign in Russia. Other interpretations have also been suggested, and the extent to which yellow-painted bombs were employed operationally is still not fully understood.
Although yellow-painted SD2s are an important and intriguing variation of the weapon, they do not appear to have formed part of the butterfly bomb attack on Grimsby and Cleethorpes.
