The second wave of Lancasters (the first to take off) had much less luck than the first. They crossed the Dutch coast at almost the same time as the first wave, but passing over Vieland AJ-W piloted by flight Lieutenant Les Munro came under light flak and lost all communication. Munro sensibly opted to abort and return to Scampton landing with his live mine on board. Some sources have stated that this was against orders but correspondence with Munro (who was known as Les Munro) has confirmed that no orders were issued against landing with the Upkeep in the event of an abort.
AJ-K was bought down on the cost of Texel at approximately 23:00 by what is believed to have been a lucky direct hit from a 10.5cm flak gun, depressed to its lowest level, the aircraft fell in the sea killing all of the crew. It is possible that this was not a large calibre gun but 20mm light flak. Remarkably the Upkeep from this aircraft exploded four weeks after the crash, causing much surprise to the local inhabitants.
Flying Officer Geoff Rice flying AJ-H misjudged his height and touched the sea. The aircraft was engulfed in water and whilst it managed to remain in the air the impact ripped the Upkeep off the bottom of the aircraft. Somehow Rice managed to keep the aircraft in the air and climb but as he did so the vast amount of water that had run into the fuselage all poured to the rear and ran out of the back almost drowning Sgt Burns, the rear gunner. The aircraft returned safely to Scampton following this trauma.
AJ-E, piloted by Flight Lieutenant Barlow also spent the first part of the flight hugging the ground. Unfortunately he hit an electricity pylon causing the aircraft to burst into flames and hit the ground a few hundred yards further on. The mine bounced free of the aircraft and in the morning was examined by German bomb disposal experts. Barlow and all of his crew died in the crash. Although the exact details of the Upkeep bomb were kept secret until well after the war, it is ironic that this bomb was thoroughly examined by German experts the following morning and by June 17th a report had been prepared by Albert Speer in his capacity as Generalinspekteur für Wasser und Energie which was sent to Herman Göring giving the following preliminary description:
“The cylindrical bomb has no stabilising fins. The diameter is 1270mm and the length is 1530mm. Each rim is secured with 30 bolts and strips of angle steel. The material used for the sides of the cylinder is 12.5mm thick whereas that used for the rims is 10mm thick. A high-explosive charge of some 2600kg is made up of 41.7% trinitroluol, 40.5% hexogen and 17.5% aluminium. The tubes for the three hydrostatic pistols, of the type used in anti-submarine depth-charges, each contain primer charges of 1820kg of Tetryl. The self-destruction charge (intended to prevent an unexploded bomb being recovered if falling on land) consists of 1255kg of Tetryl. ”
Consequently four of the five aircraft that made up the second wave never made it to the Sorpe. American Flight Lieutenant Joe McCarthy flying AJ-T did make it however, despite the delay caused by the swap to the reserve aircraft. Visibility of the dam itself was good, but there was fog in the valleys surrounding the reservoir. Despite the good visibility McCarthy had problems with the run up as he found the spire of the village church was in the way of his turn for the bomb run. In the end he dropped the bomb without it rotating (as planned) and by estimating the height as the reserve aircraft had not been fitted with the spotlight altimeter. McCarthy returned to Scampton with one tyre punctured by light flak. Things at the Sorpe dam then quietened down. It was not until almost two hours later that AJ-F with Flight Sergeant Ken Brown at the controls arrived at 03:00.
The fog that McCarthy had seen earlier had developed by this time and despite flying across the dam (which was called for by the plan) his successful run was directly across the dam rather than towards the waterside. The mine was released without spin and hit the target at almost the same spot as McCarthy’s. The reason for the change in direction and no spin was that it was not possible to get a sufficient run to bounce the bomb due to the dams location in the valley. The mine exploded but the dam however appeared to hold and Brown turned for home flying over the Möhne dam and exchanging gun fire with one its gunners. Near Hamm the aircraft came under heavy flak fire but the aircraft returned home riddled with holes.