Stevens Stopper - Fuze Immuniser Mark I

The Stevens Stopper was invented by Wing Commander James Stevens at the beginning of the Second World War.

The RAF were responsible for the disarming and disposal of unexploded bombs on and near RAF property. Some German bombs were fitted with clockwork delayed-action fuzes which prevented bomb disposal squads getting near the bomb to deactivate it. The Stevens Stopper filled the bomb’s fuze with a sticky liquid resin that prevented it from exploding. The bomb could then be disarmed safely. Care was needed to prevent the resin from setting hard in the Stevens Stopper, rendering it useless.