Living in history for a hundred years

Neal Bascomb’s new book delves into the famous sabotage of Vemork heavy water plant

winter fortress

Timothy J. Boyce
Tryon, N.C.

In The Winter Fortress, author Neal Bascomb ably recounts not one epic mission, but a protracted, 16-month attempt by British, American, and Norwegian forces to disrupt and destroy the production of “heavy water” at a hydroelectric plant located at Vemork, Norway, approximately 100 miles west of Oslo.

Heavy water is extremely rare in nature but can be laboriously manufactured, provided one has ready access to virtually unlimited quantities of water and electricity. The Norsk Hydro plant, fed by waters draining off of Norway’s remote, inhospitable Hardangervidda (the “Vidda”) had both—it was in fact the largest hydroelectric facility in the world. Ironically, when initially produced in 1935, no one had the slightest idea what heavy water could be used for, or what commercial applications were possible. But under the rubric of “build it and they will come,” Norsk Hydro constructed a processing plant and began offering heavy water for sale. Unfortunately “they” did not come, at least initially, and sales languished to the point where the unprofitable venture was shut down for a time.

It would take new advances in the field of nuclear physics to find a use for heavy water. To create self-sustaining nuclear fission (i.e., a reactor, what the author calls a uranium machine), some substance is needed to “slow” neutron activity, thus increasing the chances that freed neutrons will continue to interact with other fissile material. Because of its unusual molecular structure, heavy water acts as a suitable “moderator” (pure graphite is another).

By the start of WWII, much of this was theoretically known to scientists in the U.S., Great Britain, and Germany, although no one had yet even tried to build such a reactor. Scientists also theorized that one of the by-products of any such reactor, assuming it could be built, was a rare isotope—plutonium—a fissionable material with which to make an atom bomb. (The bomb dropped on Nagasaki on August 9, 1945, was made of plutonium.)

Thus, when Germany began to place large orders for heavy water in late 1939, and after seizing Norway on April 9, 1940, demanded delivery of ever increasing amounts of the substance, the Allies rightly feared something was afoot. It was soon decided at the highest levels of the British government that Germany should never get its hands on such supplies. This was easier said than done—the Vemork plant was situated on an inaccessible ledge of rock, surrounded by steep precipices and rivers, and located on the edge of the Vidda.

Photo: © Haukelid Family,  courtesy of Houghton Mifflin Harcourt Parachute landing in Hardangervidda (“the Vidda”) during WWII.

Photo: © Haukelid Family,
courtesy of Houghton Mifflin Harcourt
Parachute landing in Hardangervidda (“the Vidda”) during WWII.

The first Allied sabotage attempt was a complicated two-part scheme. First, four Norwegian commandos trained by the British SOE (Special Operations Executive) were successfully inserted into the Vidda (Operation Grouse) to collect intelligence, prepare for the reception of a larger group of saboteurs, and assist in the assault on Vemork. Part two, named Operation Freshman, envisioned two 15-man teams of British demolition experts being dropped via glider into the Vidda (guided in by the Grouse team), where they would storm the facility and destroy everything inside.

Operation Freshman (November 19-20, 1942) was a complete fiasco. Visibility on the night of the drop proved poor, the radio homing devices failed to function, the planes could not locate the landing spot, and the tow ropes broke unexpectedly. Net result: one towing plane crashed, as did both gliders, killing many immediately. Those who survived were quickly captured and subsequently executed pursuant to Hitler’s so-called commando order.

News of this disaster had barely reached England when another plan was hatched. Utilizing the Grouse team (still intact, but now renamed Swallow), a group of six additional Norwegian saboteurs, many familiar with the area, would be parachuted into the Vidda. This new team (dubbed Operation Gunnerside) would, together with Swallow, 1) somehow penetrate the plant, 2) destroy all existing stocks of heavy water as well as all means of production, and 3) escape on skis into Sweden, some 250 miles away. Now that the Germans had been thoroughly alerted to the Allies’ intentions and had hardened their defenses around Vemork considerably, this operation seemed like nothing short of a suicide mission, but the Gunnerside team was eager to go.

With incredible skill and courage, on February 27-28, 1943, the combined Swallow/Gunnerside teams skied to the target, descended a vertiginous gorge, ascended the opposite cliff, broke into the plant undetected, set their charges, and escaped, all without firing a single shot. Despite a massive German manhunt, not a single member was captured—a feat the German military commander of Norway, General von Falkenhorst, later called “the finest coup I have ever seen.”
The Allies, exhilarated by their success and confident that the Vemork raid had set back production by a year or more, were therefore stunned when intelligence reports surfaced that the plant was operating once again after only a few months. The Allies next decided to bomb Vemork by air, over the vehement objections of their Norwegian colleagues, who feared civilian casualties. The raid on November 16, 1943, did nothing to damage the heavy water stocks or equipment, but did kill 21 civilians. Despite this seeming failure, the attack convinced the Germans that the operation would never be safe in Norway and induced them to move everything (water and equipment) to Germany for protection.

This decision opened the way for the fourth and final act in the drama. The transportation route from Vemork, isolated as it was, required shipment by rail to Lake Tinnsjø, a ferry ride over the 18-mile length of the lake, followed by a further rail journey to a suitable port on the coast. This gave the sole member of Operation Gunnerside still remaining in Norway approximately two weeks to prepare a plan and enlist additional Resistance members. Yet again, the operation (February 19-20, 1944) was pulled off flawlessly. A bomb was planted on the ferry, timed to explode over the deepest part of the lake, which it did, sending the cargo to a watery grave.

Despite the hyperbolic subtitle, Hitler had no atomic bomb, indeed had nothing comparable to the Manhattan Project. One need only compare the vast resources (material, personnel, and financial) committed by the United States, which did not produce a usable bomb until after the war in Europe had already ended, with the fitful efforts of the German program, and the lack of any support afforded the Nazi scientists by the German government (more focused on technologies promising a quicker and more certain payoff), to conclude that Germany wasn’t even close to building a bomb, and the Allies’ fears were overblown. Of course, none of this was known by the Allies in 1942 and 1943, and they had to assume the worst—that the Germans were in fact well ahead in the development of a working reactor and a nuclear weapon.

The members of Operations Grouse, Freshman, Swallow, and Gunnerside and the team that sunk the ferry on Lake Tinnsjø never really knew why destroying heavy water was so important; they only knew that it had to be destroyed. Moreover, the secrecy surrounding the Allies’ own atomic program meant that their feats could not be widely publicized during the war. The members were simply promised: “[Y]our actions will live in history for a hundred years to come.”

It’s a good bet that that promise will be fulfilled. After all, it is now almost 75 years since the Grouse team first landed on the Vidda. They and their compatriots endured ferocious winter weather, near starvation, the constant threat of discovery, and even death, and yet their patriotism, courage, and fortitude in the face of all this still inspires worthy books such as The Winter Fortress. As the official historian of the SOE, M.R.D. Foot, later observed: “If SOE had never done anything else, ‘Gunnerside’ would have given it claim enough on the gratitude of humanity.”

Timothy J. Boyce is the Editor of From Day to Day: One Man’s Diary of Survival in Nazi Concentration Camps, by Odd Nansen (Vanderbilt University Press).

This article originally appeared in the July 29, 2016, issue of The Norwegian American. To subscribe, visit SUBSCRIBE or call us at (206) 784-4617.

Norwegian American Logo

The Norwegian American

The Norwegian American is North America's oldest and only Norwegian newspaper, published since May 17, 1889.