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Here’s an update from Wikipedia- the dam-buster WWII bombs were over 9000 pounds:

Testing of Upkeep prototypes with inert filling was carried out at Chesil Beach, Dorset, flying from RAF Warmwell in December 1942, and at Reculver, Kent, flying from RAF Manston in April and May 1943, at first using a Vickers Wellington bomber.[11] However, the dimensions and weight of the full-size Upkeep were such that it could only be carried by the Avro Lancaster, which was the largest British bomber available at the time, and nonetheless had to undergo considerable modification in order to carry it.[12] In testing, it was found that Upkeep’s spherical casing would shatter on impact with water, but that the inner cylinder containing the bomb would continue across the surface of the water much as intended.[13] As a result, Upkeep’s spherical casing was eliminated from the design. Development and testing concluded on 13 May 1943 with the dropping of a live, cylindrical Upkeep bomb 5 miles (8 km) out to sea from Broadstairs, Kent, by which time Wallis had specified that the bomb must be dropped at “precisely” 60 feet (18 m) above the water and 232 miles per hour (373 km/h) groundspeed, with back-spin at 500 rpm: the bomb “bounced seven times over some 800 yards, sank and detonated”.[14]

In the operational version of Upkeep, known by its manufacturer as “Vickers Type 464”, the explosive charge was Torpex, originally designed for use as a torpedo explosive, to provide a longer explosive pulse for greater effect against underwater targets; the principal means of detonation was by three hydrostatic pistols, as used in depth charges, set to fire at a depth of 30 feet (9 m); and its overall weight was 9,250 pounds (4,196 kg), of which 6,600 pounds (2,994 kg) was Torpex. Provision was also made for “self-destruct” detonation by a fuze, armed automatically as the bomb was dropped from the aircraft, and timed to fire after 90 seconds.[15] The bomb was held in place in the aircraft by a pair of calipers, or triangulated carrying arms, which swung away from either end of the bomb to release it.[16] Back-spin was to begin 10 minutes before arriving at a target, and was imparted via a belt driven by a Vickers Jassey hydraulic motor mounted forward of the bomb’s starboard side. This motor was powered by the hydraulic system normally used by the upper gun turret, which had been removed.[citation needed] Aiming was by a pair of intersecting spotlight beams, which, when converged on a surface of water, indicated correct height for the aircraft, and by a simple, hand-held, triangular device: with one corner held up to the eye, projections on the other two corners would line up with pre-determined points on the target when it was at the correct distance for bomb release. In practice, this could prove awkward to handle, and some aircrews replaced it with their own arrangements, fixed within the aircraft itself, and involving chinagraph and string.[17]

On the night of 16/17 May 1943, Operation Chastise attacked dams in Germany’s Ruhr Valley, using Upkeep. Two dams were breached, causing widespread flooding and damage, and loss of life. The significance of this attack upon the progress of the war is debated.[18] British losses during the operation were heavy; eight of the 19 attacking aircraft failed to return, along with 53 of 113 RAF aircrew.[19] Upkeep was not used again operationally. By the time the war ended, the remaining operational Upkeep bombs had started to deteriorate and were dumped into the North Sea without their detonation devices.[20]

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