'Musketoon' was a British special forces raid to destroy the hydro-electric power plant in the Glomfjord on the west coast of German-occupied Norway (15/21 September 1942).

The power provided by this facility was essential to the operation of an aluminium smelting plant deemed vital to the German war effort. The raiding party comprised two officers and eight men of the British No. 2 Commando and two men of the Free Norwegian armed forces who were part of the Special Operations Executive. Crossing the North Sea by submarine, on arrival in Norway they attacked and damaged the plant, which was closed for the rest of the war.

To evade German search parties, the commandos split into two groups. One group of four men reached Sweden and was eventually repatriated to the UK. The second group was captured: one man died of wounds and the other seven were taken to Germany, interrogated and then executed at Sachsenhausen concentration camp.

After the British Expeditionary Force had been evacuated from Dunkirk in 'Dynamo' during June 1940, Prime Minister Winston Churchill called for the establishment and deployment of a force equipped to inflict casualties on the Germans and bolster British morale, and also ordered the Joint Chiefs-of-Staff to propose measures for an offensive against German-occupied Europe: 'They must be prepared with specially trained troops of the hunter class who can develop a reign of terror down the enemy coast.' A staff officer, Lieutenant Colonel Dudley Clarke, had submitted a proposal to General Sir John Dill, the Chief of the Imperial General Staff, who approved Clarke’s proposal. Three weeks later, the first commando raid took place. The raiders failed to gather any intelligence or damage any German equipment but killed two German sentries.

The original No. 2 Commando was formed from British volunteers and from the start was intended to be a parachute unit. On 22 June 1940, No. 2 Commando was turned over to parachute duties and on 21 November, was renamed the 11^th Special Air Service Battalion and eventually 1^st Parachute Battalion. After its renaming as the 11^th Special Air Service Battalion, a second No. 2 Commando was established under the command of Lieutenant Colonel A, C. Newman, and it first action took place when two of its men supported No. 3 Commando in the 'Archery' raid on Vågsøy in December 1941, followed by the 'Chariot' raid on St Nazaire in March 1942. The next action involving men of No. 2 Commando was 'Musketoon', whose objective was the destruction of the Glomfjord hydro-electric power plant, to the south of Narvik, which supplied energy to an aluminium plant in the area.

The construction of the Glomfjord power station at the end of Glomfjord began in 1912 on a plateau dropping straight down to the sea, and the facility was commissioned in 1920. The plant comprised three buildings, of which the longest was the machinery hall, the middle housed the control room and offices, and the last was three-storied structure known as the apparatus house. The hydro-electric power station was supplied with water by two pipes coming down the mountain from inland lakes. As well as the aluminium factory, the station supplied power to local villages.

Two officers and eight men of No. 2 Commando and two Norwegian non-commissioned officers of the 1^st Norwegian Independent Company, part of the Special Operations Executive, were selected for 'Musketoon'. The two commissioned officers were Captain Graeme Black, from Ontario in Canada, and his second in command, Captain Joseph Houghton. The Norwegian corporals were Erling Djupdraet and Sverre Granlund. Before departing for Norway, the party trained for a fortnight on a large country estate in Scotland. During the operation’s planning stage, it was decided that after the operation the party would be recovered by a Short Sunderland flying boat, but this aspect of 'Musketoon' was cancelled before the mission as a result of the risk to the aeroplane, so the party was now to head for neutral Sweden. Each man was issued with special equipment, including a silk map of Norway and Sweden, a rice paper map of the north-western USSR and Norwegian bank notes. Each man also carried two compasses (one sewn into each collar tab), a hacksaw blade, a fighting knife and a Colt M1911 pistol. The only other small arm taken was a suppressed Sten gun, carried by Houghton.

To transport the party across the North Sea, the Free French submarine Junon was used. This boat was selected because in silhouette it had the appearance of a U-boat, which could have been an advantage had the boat been sighted on the surface. The submarine left the Orkney islands group on 11 September under escort in British waters by other submarines, the British Sturgeon, Tigris and Thunderbolt. Junon crossed the North Sea without being detected and, once near the Glomfjord, rose to periscope depth and discovered that a fishing boat was trailing it. The boat crash-dived, but this sighting does not appear to have compromised the operation. Black, the commander of the raid, had opted against a frontal assault since he suspected that any German defences would expect this. The submarine entered the Bjaerangsfjord, just to the south of the Glomfjord, on 15 September.

The submarine settled on the bottom of the fjord until the fall of night and then surfaced at 21.15 to put the commandos ashore by dinghy. Reaching the shore, the party concealed its dinghy under some stones and moss, and set out across the mountains to the Glomfjord, reaching the Svartisen undetected. Houghton and Granlund went ahead to reconnoitre the area before the rest of the party began to climb the mountain. At one stage the men had to traverse a near-vertical rock face before reaching the summit. Black did not know that their presence was suspected, but a German topographical party was in the area and its commander, Leutnant Wilhelm Dehne, had spotted some unidentified figures above the Glomfjord. Later he discovered some British cigarette packs and the remains of a camp. Fortunately for the commandos, his route back to Glomfjord took Dehne away from their new camp overlooking the power station.

Resting in their hide-out for the following day, the commandos went over their plan of attack and subsequent withdrawal from the area. They left their encampment at 20.00 on 17 September to begin the attack. On their approach they detected a small craft on the fjord, and fearing they would be spotted decided to postpone the action and return to camp. By dawn they had not been able to reach their hide-out, and despite being in an exposed location they still decided it would be best to stay put until the fall of darkness, after which they reached their hide-out once again. At this point, however, the commandos were running short on supplies and Black ordered the attack to be made during the following night, 19/20 September.

For the attack, the commandos were divided into two groups. One group, comprising Lance Sergeant O’Brien, Lance Bombardier Chudley and Private Curtis, was to attack two high-pressure water pipes, each some 7 ft (2.1 m) in diameter, leading from the top of the mountain into the plant. Reaching their objective, they planted plastic explosives in a round pattern to blow a 3-ft (0.91-m) hole in the pipes. Attaching a 30-minute delayed fuse, they waited to hear the sound of detonations inside the plant, which was the signal to activate their fuse.

The other nine commandos had set out for the rear of the power plant. Seven men entered the machinery hall, leaving two men on guard. The commandos in the power station discovered that the Germans had left the control room and only a Norwegian engineer was on duty. Sergeant Smith and Private Fairclough were detailed to plant their explosives among the machinery in the powerhouse and the other men located the area where the Norwegian work force worked and slept. The workers were gathered and ordered to leave the station via an access tunnel more than 1 mile (1.6 km) long, which was the only land route between the station and the villages in the fjord. On the men’s approach to the tunnel, a German guard was killed by Granlund but another managed to run off down the tunnel to raise the alarm. In order to delay the arrival of German reinforcements, the commandos left smoke bombs inside the tunnel. By this time the commandos in the station had set their plastic explosives with 10-minute delay fuses on both turbines and generators.

On hearing the explosions at the power plant, O’Brien’s group detonated their explosives, and both groups then withdrew into the hills, just as German reinforcements started to arrive at the plant. The Germans were unwilling to enter the tunnel, fearing it might be booby trapped, and therefore used boats belonging to the villagers to bypass the tunnel and reach the station. Granlund had pressed on ahead of the main group trying to find a foot bridge to aid their escape. He found a mountain hut occupied by three Norwegians whom he asked for directions, but the best they could manage was to draw him a map. Granlund left to look again but returned to the hut soon after that, being unable to find it in the dark at the same time as Houghton and Djupdraet, the other Norwegian. Unknowingly, while Granlund had been away two Germans had arrived at the hut and were busy questioning the occupants. In the ensuing fight, one of the Germans was killed and the other wounded. Djupdraet was also wounded, stabbed in the stomach with a bayonet.

The other commandos arrived at the scene and administered first aid to Djupdraet, who was so severely wounded that they decided to leave him to get treatment. The remaining commandos now split into two groups to evade German search parties and made their way farther up the mountain. One group, comprising O’Brien, Granlund, Fairclough and Trigg, went north around the mountains. The second group, comprising Black, Houghton, Smith, Chudley, Curtis, Abram and Makeham, took the southern route. The second group was discovered by the Germans, who opened fire, wounding Houghton in the right arm. Surrounded, the group had little option but to surrender. The O’Brien group split up, Granlund setting off by himself. The men of this party eventually reached Sweden without further incident and all four were repatriated by air. Djupdraet died of his wounds in hospital, three days after the raid. The other seven prisoners were sent to Germany.

The unwounded prisoners were sent to Colditz Castle and put into the solitary confinement. On 13 October 1942 the men were taken to the SS-Reichssicherheitshauptamt headquarters in Berlin, where they were interrogated individually by SS-Gruppenführer Heinrich Müller. They remained in Berlin until 22 October, when they were taken to the Sachsenhausen concentration camp. On the next day they were each shot in the back of the neck and their bodies cremated. These commandos were the first to die under the 'Commando Order' issued on 18 October 1942 by Adolf Hitler, which called for the execution of all captured commandos. The official German story given to the Red Cross was that the seven men had escaped and not been recaptured.