Like the Tallboy, after the hot molten Torpex was poured into the casing, the explosive took a month to cool and set. Therefore, the Grand Slam had a low rate of production and consequent high value for each bomb. As a result, aircrews were told to land with their unused bombs on board rather than jettison them into the sea if a sortie was aborted.[12] If returning with an undropped bomb the bomber had to divert from Woodhall to Carnaby which had a longer runway.[10]
https://en.wikipedia.org/wiki/Grand_Slam_(bomb)



























