To guarantee detonation, three Type 47 long delay fuzes were fitted inside the rear of the bomb. This dramatically improved reliability of the weapon; even if two of the fuzes failed, the third would trigger detonation. At least 2 Tallboys failed to explode, one during the second attack on the Sorpe dam; it was found during repairs in late 1958 when the reservoir was emptied and a second was found in Świnoujście in Poland (formerly Swinemünde) in 2020. While being remotely defused, this second bomb detonated in October 2020.