Operation Freshman
Operation Freshman was the codename given to a British airborne operation conducted in November 1942 during World War II. It was the first British airborne operation using Airspeed Horsa gliders, and its target was the Vemork Norsk Hydro hydrogen electrolysis plant in Telemark, Norway which produced heavy water as a by-product.
By 1942, the German nuclear weapons programme had come close to being able to develop a nuclear reactor, but for the reactor to function it would require a great deal of heavy water. The source of the heavy water was the Norsk Hydro plant, which had been occupied since 1940.
When the British government learned of the German nuclear developments, it was decided that a raid would be launched to destroy the plant and deny the Germans the heavy water required to develop a nuclear weapon. Several plans were discussed and discarded as impractical; it was decided that a small airborne force composed of sappers from the Royal Engineer units attached to 1st Airborne Division would land by glider, a short distance from the plant, demolish it with explosives and then escape over the Norwegian border into Sweden. After an extensive training period, the airborne force took off in two aircraft–glider combinations on the night of 19 November 1942. Both the gliders and tugs were operated by aircrews attached to HQ No. 38 Wing RAF.
The tugs and gliders managed to reach the Norwegian coast, but neither was able to reach their objective. The first pair suffered from navigational difficulties and severe weather, which resulted in the tow rope snapping and the first glider crash-landing, with its Halifax tug aircraft returning to base. Three airborne troops were killed and the survivors were captured shortly after the crash. The second pair fared even worse, with both the aircraft and glider crashing into a mountain after the aircraft flew low in search of the first glider. Both members of the glider crew were killed instantly, while one soldier passenger died soon afterwards from his injuries. Those who survived the crashes were captured by German forces and killed as a result of Wehrmacht's Commando Order, which stated that any Allied personnel captured while involved in commando operations were to be killed immediately. At the end of the war, the Wehrmacht personnel involved were tried, sentenced to death and executed for their part in the murders.
Background
The German government began development of an atomic weapons programme after two scientists, Lise Meitner and her nephew Otto Frisch, declared in the February 11 1939 issue of the scientific journal Nature that atomic fission was possible and could release immense amounts of energy. By September 1941, the German scientists assigned to the programme had determined how a nuclear reactor could be developed. This required significant quantities of heavy water to act as a neutron moderator to encase the uranium which would be used to provide the material for a nuclear weapon. Heavy water was extremely scarce and difficult to produce, and Germany only possessed a small amount which had been produced in laboratories. Norway possessed a large stockpile which was produced by the Vemork Norsk Hydro chemical plant near the village of Rjukan, but the Norwegian government would not sell more than three gallons of heavy water a month, becoming suspicious of the sudden increase in demand for the water by the German government. When Norway was invaded and occupied by Germany in April 1940 this obstruction ended; the Vemork plant was captured and began producing heavy water for the German atomic weapons programme. Production of heavy water was slowed initially due to the effects of the fighting in Norway and a drought in the area, which led to a lack of water to provide hydroelectric power for the plant. Once the weather improved and snow began to melt, providing enough water to create sufficient hydroelectric power, production continued.By mid-1942 it had come to the attention of the British government that the plant had begun to produce large quantities of heavy water and was stockpiling it for later use. The decision was therefore taken that the plant and the stockpiles of heavy water would have to be destroyed in order to impede the German programme. Several methods for destroying the plant were considered. The first was a mass raid by Royal Air Force bombers, but this was rejected due to the difficulty in locating the plant during night bombing, the principal bombing tactic used by the RAF at the time, and the heavy casualties that would be inflicted on the local Norwegian population during a night raid. An attack by Norwegian saboteurs was also ruled out, as was landing troops by PBY Catalina flying boat on Lake Møsvatn, from the target, the latter due to the steepness of the surrounding mountain slopes and the inability of flying boats to land on the ice. It was decided that a raid by glider-borne airborne troops would have the greatest chance of success. The area around the plant would be difficult to land on, but a possible landing site for gliders was located near the Møsvatn dam, although it would require considerable skill on the part of the glider pilots in order to land safely.
Preparations
Operation Grouse
In March 1942 the British Special Operations Executive had recruited Einar Skinnarland, a Norwegian engineer who worked at the Møsvatn dam. Skinnarland had successfully sailed to Britain and was parachuted back to Telemark after ten days of intensive training. Having several contacts within Vemork he was able to roughly identify the disposition of German troops and other defences. Additionally SOE decided to send an advance party of Norwegian agents into Telemark, and began intensively training a four-man team over the summer. The party, code-named Operation Grouse, was led by Jens-Anton Poulsson and also included Knut Haugland, Claus Helberg and Arne Kjelstrup. The Norwegians, all people local to the area with exceptional outdoors skills, underwent extra outdoor training in Scotland as well as learning the skills necessary to operate in occupied territory; including sabotage, radio transmitting and "irregular warfare".The Grouse team were ready to be inserted by October. Several flights were made but aborted due to bad weather, before the team finally dropped on 18 October. The team landed at Fjarefit on the Hardangervidda and spent the next 15 days trekking towards Møsvatn, where they made contact with Skinnarland's brother, Torstein. Once they had established contact with London the party began making preparations for the arrival of the British commandos. A suitable glider landing site was chosen south west of Møsvatn dam and the team reconnoitred the area to help Combined Operations decide the best way to attack the plant.
German defences
The geography of the area around the village and the plant meant that attacking the plant and destroying the existing stocks of heavy water would be extremely difficult. Both were situated in a deep valley which possessed thickly–forested sides that rose almost vertically from a narrow river–bed, and which was overlooked by Gaustatoppen, a mountain approximately high; the plant itself had been built on a broad rock shelf above the river bed.Einar Skinnarland had observed the German defences over the summer and passed the information back to SOE. Later reconnaissance by Torstein Skinnarland and the Grouse team was also transmitted to London in the weeks leading up to the operation. In early October Generaloberst Nikolaus von Falkenhorst, the commander in chief of the German forces in Norway, had visited the plant. While there he warned the local garrison that he believed the plant was a likely target for British commando raids, but crucially he did not have the resources to increase the manpower there. Although Einar Skinnarland had observed a garrison of 100 men in the village of Rjukan, 20 at the dam and about 55 near the main plant during the summer, by October this had been reduced to about 12 at the plant, 12 at the dam and approximately 40 in Rjukan. Most of the men were elderly or infirm Austrians under the command of an elderly captain, although well trained German regulars periodically passed through Telemark. Skinnarland also believed that Gestapo agents were in the area.
The Germans had erected three iron hawsers across the valley to prevent low flying bombing raids but on the ground most of their defences were positioned to prevent an assault from the ridge above the plant, the direction from which they believed an attack was most likely. Minefields and booby traps predominantly protected this side of the plant, but there were also searchlights on the roof and a machine gun nest near the entrance. A single bridge crossed the steep gorge in front of the plant, but was normally only protected by two guards. There were 300,000 German troops in Norway at this time and reinforcements could quickly be called into the area, which would complicate the commandos' escape to the Swedish border.
Planning
The Headquarters staff of Combined Operations at the War Office was tasked with devising a plan for the glider-borne assault on the plant, as it had been with previous airborne and commando operations, such as Operation Biting. This was the first British airborne operation ever to use gliders; all previous operations had been conducted solely with parachutists. The staff decided that although gliders would be the most suitable for the operation due to the heavy loads to be carried by the airborne troops, and the possibility that they could be widely dispersed if they were dropped by parachute, the airborne troops would still be trained for a possible parachute insertion if the landing zone for the gliders was found to be unsuitable. Because of the complicated and technical nature of the operation, which would see the plant rigged with explosives and then detonated, it was believed that a minimum of twelve to sixteen men was required, and that they would all have to be skilled engineers. The important nature of the operation also led to the force being doubled in order to duplicate it, to ensure that even if half of the force were killed, the survivors would have the necessary skills to complete the operation. The selected troops were volunteer parachutists chosen from the sappers of 9th Field Company Royal Engineers and 261st Field Park Company Royal Engineers attached to 1st Airborne Division, because the only parachute-trained Royal Engineers unit in existence at the time, 1st Parachute Squadron Royal Engineers, was already deployed in North Africa with 1st Parachute Brigade. Both of the duplicated units that were to participate in the operation were to be commanded by officers from the Royal Engineers; the first by Lieutenant A.C. Allen and the second by Second-Lieutenant M.D. Green, who was later replaced by Lieutenant D.A. Methven when he was injured during a training accident three days before the operation was to begin.Image:Vemork 2008-02-08.JPG|thumb|alt=Snow covered winter wooded landscape, with factory on opposite slope of hills|upright|The Vemork hydroelectric plant in snow in 2008
The Royal Air Force unit selected to transport the sappers was 38 Wing, which was commanded by Group Captain T.B. Cooper; it was provided with a special allotment of three Handley Page Halifax heavy bombers for the operation, which were the only British aircraft in existence at the time which were capable of towing Horsa gliders the distance required and then returning to their base. The SOE agents selected a landing zone for the sappers, which was approximately from the Norsk Hydro plant and could not be observed by German patrols. The plan for the operation called for the sappers to land in the two gliders at the landing zone, guided in by the SOE agents equipped with Eureka radio beacons. Once they had successfully landed, the sappers would be escorted to the plant by the SOE agents, demolish the plant and its stocks of heavy water, and then cross the Norwegian border into neutral Sweden.
Combined Operations initially suggested the men should fight their way to the Swedish border, but MI9 believed their chances of survival were better if they attempted to disguise themselves as Norwegians and travel in pairs. In order to facilitate their escape the men were provided with civilian clothes, simple Norwegian phrases and escape sets containing money and maps. They were also ordered to shave any moustaches and grow their hair long in order to blend in with Norwegian men.