The Heavy Water War: Beating Hitler to the Bomb

Author: John Sadler

Publisher: Amberley, 2024 (320 pages, 1 map, 28 bw photographs, 5 colour photographs)

During the Second World War, the Allies mounted a number attempts to prevent Germany from harnessing hydroelectric plants in occupied Norway to produce heavy water (Deuterium Oxide or DO), a major constituent in any potential atomic weapon. As Professor Lars Ohrstrom, states in one of the quotes in this book: DO could have been employed ‘to slow down neutrons and sustain a nuclear chain reaction.’ Clearly, the risk of allowing this to happen was far too great to contemplate, and something needed to be done to prevent the Nazis from developing an atomic bomb, and potentially holding the world to ransom by suing for peace while backed up by such a threat.

Production of DO centred on the Vermork Power Station beside the Rjukan Waterfall at Telemark, and thus it became the primary target for the Allies. In reality the Nazis were never as close to perfecting an atomic bomb as the Allies feared, but that was not fully appreciated at the time. Relying on a range of primary and secondary sources, John Sadler tells the story of the Commando and bombing raids that were launched to prevent Hitler obtaining an atomic weapon capability. He is well placed to do so, given he has travelled extensively in Norway, and as a lecturer/battlefield tour guide/living history interpreter and heritage consultant, has a life-long passion for military history, including the Second World War. Notably, he has consulted material on Special Operations Executive (SOE) held at the Resistance Museum, Oslo, and his ‘Select Bibliography’ lists many of the sources around which the narrative is based, and might serve as inspiration for anyone desiring further reading or more analysis on the subject. Likewise, another boon is that the book comprises lengthy appendices. These reproduce significant documents as follows: 1. Proclamation to the People of Norway by the King of Norway and H.R. Nygaardsvold, Prime Minister, April 10^th 1940; 2. Details on Operation ‘Freshman’; 3. ‘Leif Tronstad-the Heavy Water Hero’ from Chemistry World, 7 February 2018, Prof. Lars Ohrstrom, Chalmers University of Technology; 4. ‘Operations Gunnerside and Grouse-Special Operations during World War II against German controlled Heavy Water Plant in Norway’ by Maj. Frode Kristoffersen, Norwegian Army, United States Marine Corps Command and Staff College; 5. The Helberg interview (CIA Archive) Studies Archive Indexes Vol. 36 No. 3 The Vermork Action: A classic act of sabotage, Claus Helberg.    

The narrative is couched in an accessible style, sometimes journalistic and chatty, which allows the author’s enthusiasm to shine through, such as when he discusses SOE weapons and equipment, whereas, at other points it reads more along the lines of an authoritative, historical account, depending on the sources consulted. Chapters are well supported by notes and a glossary towards the back of the book. Helpfully, at the start of the book is a list of the main characters that appear, particularly valuable for readers who will probably not be familiar with the Norwegian personnel involved, plus their biographical details make for fascinating reading. The first chapter describes the situation regarding the production of DO, and conditions in occupied Norway, including the nature of the resistance to the Nazis, such as the legendary ‘Shetland Bus,’ a trawler skippered by Leif Larsen, that completed over 50 journeys between the UK and Norway, to ferry arms and supplies to resistance fighters etc. The second chapter, ‘The Uranium Club,’ discusses the nature of atomic research during the wartime era in Germany, and further afield, plus an audacious attempt in spring 1940 to secure the then existing Norwegian supply of heavy water, and spirit it away virtually from under the Nazi’s noses. Chapter 3: ‘The Ministry of Ungentlemanly Warfare’ outlines the work of SOE, especially how it trained and equipped agents. As Sadler states, ‘The process was cumulative, agents were turned into killers, not just in the sense of their ability to execute lethal moves but in their confidence and assurance…’

The next chapter concerns the activities of Operation ‘Grouse,’ whereby a small SOE party was inserted into Norway to pave the way for a larger force, and had to survive in harsh conditions on the Hardanger Vidda for several months, ably assisted by Einar Skinnarland a local from Rjukan, who proved keen to help. Parachute jumps could be difficult at any-time, let alone when landing in Nazi occupied Norway. These men came down via static line from a Halifax bomber, along with several containers of weapons, equipment and rations, something the book describes extremely evocatively. Similarly, the author encapsulates how unbelievably hard it was for the men trying to live on the Vidda, noting that they all started to suffer from the effects of undernutrition. Operation ‘Freshman’ (19/20 November 1942) forms the substance of the next chapter. It was designed as a full-blown Commando attack to hinder the German atomic research programme. Unfortunately, the gliders bringing in the assault parties crashed, and those occupants who were not killed outright, were executed by the Germans in accordance with Hitler’s infamous Kommandobefehl, an issue the author discusses insightfully, including advancing plausible evidence based on John Warwicker’s work, as to how this order might have originated.

The book goes on to describe Operation ‘Swallow’ (18 October 1942), an airborne drop of part of the Company Linge near Vermork to prepare for a gliderborne force. This unit was officially Norwegian Independent Company Number 1 but was renamed after Martin Jensen Linge (1894-1941) DSM, the officer who had been a prime mover behind it. Effectively, ‘Grouse’ morphed into ‘Swallow,’ and the book again vividly describes the challenges faced, including scurvy, and something termed ‘polar disease’ that effected people living in isolation under severe conditions. This reviewer appreciated the additional discussion on Special Training School Number 61 that revealed something on the preparations undergone by SOE personnel destined for clandestine work in occupied Europe. During February 1943, Operation ‘Gunnerside’ was launched to reinforce ‘Swallow’ by landing an airborne force in Norway, and this led to the sabotaging of the power plant when the SOE trained Commandos attacked it. One of the raiders, Knut Haukelid, subsequently ensured that around a hundredweight of heavy water being transported to Germany was sunk along with the ferry taking it across Lake Tinn, something described in detailed by the book. A further chapter is devoted to the daring escape to Sweden made by those engaged in ‘Gunnerside,’ and as the author shows famously the above events were immortalised in the popular imagination by the film Heroes of Telemark.  

The penultimate chapter highlights the controversial decision to launch a bombing raid against Vermork in late 1943, because ‘SOE had scotched the snake, not killed it,’ albeit ‘Gunnerside’ was a successful undertaking. Finally, the book devotes a chapter to the legacy of ‘Gunnerside’ and ‘Grouse/Swallow,’ explaining that they demonstrated what could be achieved by motived well equipped and highly trained raiders, plus outlines what became of many of the participants. As M. R. D. Foot, the official historian of SOE commented: ‘If SOE had never done anything else, ‘Gunnerside’ would have given it claim enough on the gratitude of humanity.’ This book provides enjoyable reading, is based on an interesting array of archives and published secondary sources, and provides a fitting tribute to the bravery, skill and dedication of those involved in ensuring that Hitler never acquired ‘the bomb.’

James Goulty (Military historian & author with a particular interest in twentieth century warfare).