SIS Norway background to the Vemork hydroelectric plant

In July 1941, other than some intermittent communications from Skylark B, all the Norwegian section could report was the early stages of four additional operations, three of which aimed to provide ship-watching reports from along the coast. During 1941 a series of operations identified by Greek code-names were initiated. Most of these emanated from suggestions by Norwegian escapees that they should return to Norway equipped with a wireless set, or that they had contacts (particularly in shipping circles) who could already operate a set and who would willingly act as observers. One operation was ‘Epsilon’, run by Newill’s successor, Eric Welsh. In particular this investigated German interest in heavy water, an important component in the development of an atomic bomb, and produced by the Norsk Hydro hydroelectric plant at Rjukan in south-central Norway. In October 1941, Leif Tronstad, a professor of chemistry in Trondheim and a member of the Skylark B network, escaped to England where he was interviewed by R. V. Jones, an Air Ministry official seconded to SIS’s scientific section (which he headed), and Professor Frederick Lindemann, Churchill’s scientific adviser.³ Based on Tronstad’s information Welsh (a scientist himself ) proposed the destruction of the plant by bombing or sabotage. ‘The removal of this source of supply’, he wrote, ‘would completely cripple any designs the Germans may have with regard to this type of weapon and on the other hand, the Allies are not in a position to use this potential weapon themselves for at least eighteen months, as they are only now considering building a suitable plant in America.’ Following the disastrous failure of a Combined Operations raid, the machinery was temporarily disabled and heavy-water stocks destroyed in a well-executed SOE sabotage attack in February 1943. This demonstrated, at least in this instance, that SIS intelligence and SOE operations could successfully and productively be integrated.