The communist resistance group BOPA stood for up to half of all material damage done by sabotage actions during German occupation of Denmark in WWII. On June 6th 1944 they assaulted and blew up the Copenhagen bicycle factory Globus that had been converted to manufacture parts for German airplanes. The assault was a regular partisan attack that involved up to a hundred resistance fighters. It was one of the most spectacular sabotage actions during German occupation of Denmark in WWII.

Jørgen Jespersen, the 18 year old partisan who led the assault team later described the assault in his memoirs "KK og Krigen" (Download).

Below is my translation of his description of the assault.

The Globus factory was located in Glostrup on [the road] Roskildevej near the Western Ramparts. It manufactured aircraft parts for the Germans, and the workers were specially selected with a large proportion of Nazis among them. We had to abandon the idea of infiltrating any of our people into the company, a method we otherwise often used for hard-to-reach targets. And Globus was certainly that. The guards consisted of approximately 15 Sommer people (a Nazi corps of former Eastern Front fighters – some nasty characters [note]) armed with rifles, carbines, submachine guns, and pistols.

The factory grounds were rectangular, featuring two long two-story buildings housing the actual machinery and workshops, along with several smaller buildings, including the guardhouse. It was all surrounded by a tall barbed-wire fence inside which a concrete bunker with firing slits was positioned at each corner. It was summer and hot, which meant the guards preferred staying out in the open rather than inside their bunkers. We were aware that we couldn't overpower the guards outright, and that we lacked the means to force them out of their bunkers if they retreated into them. Furthermore, the situation was complicated by the guards having direct telephone connections to Dagmarhus [Gestapo's Copenhagen headquarters] and to the Avedøre Barracks, which was full of German soldiers and located only 4 km from the factory. On the Western Ramparts, 500-600 meters away, there was a German post of about 20 men, and Roskildevej had heavy traffic, frequently including German soldiers.

We realized that the only way to get onto the factory grounds was to neutralize the guard force. We hadn't tried that before. True, we had been in firefights several times, but that was by accident, when something had gone wrong. Most of us had no military training, and our marksmanship was limited. Only a few of us had ever practiced target shooting. For months, we reconnoitered and spied on the factory, particularly the guards.

This time, we broke with our principle of only briefing our people on the plans immediately before an action. This principle was to avoid the risk of the action being betrayed to the Germans or careful planning being wasted if a comrade happened to be arrested. A couple of days before the action, we assembled the assault team – which was my section – along with the leaders of the covering groups for instruction. This took place at the YMCA Soldiers' Home on Gothersgade in Copenhagen. For the occasion, we had prepared a map of the factory and its surroundings. Then, the task of each group and each man was reviewed in detail.

The assault team, my section, consisted of about 20 men. Including the covering groups, we totaled approximately 50 men. Getting such a large force into position for the attack without the guards detecting and being warned was therefore a major challenge. This required considerable ingenuity: some arrived as boyscouts on bicycles with guns in their backpacks, some by train, and others by bus. Several came in cars so we could make a quick getaway after the action. The cars were almost all procured shortly beforehand. The explosives were transported there on two trucks. Along the east side of the factory, there were about three villas, which we occupied before the action, partly to have a reporting point and a telephone. A single villa on the north side, across Roskildevej from the factory's main entrance, was also occupied. On the south side was a fruit orchard, which allowed us to crawl almost right up to the fence.

The assault team arrived 2-3 men at a time and took up positions on the three sides of the factory in the villas and in the fruit orchard. Exactly at 7:00 PM, the assault team was to be in position, and the team near Roskildevej was to start the attack by neutralizing the guards at the gate. We had counted 5 men on guard duty, and they were all standing near their bunkers. I myself was positioned with Brandt and 4-5 other men in the orchard south of the factory. We had crawled as close as we dared towards the guard pacing back and forth; we could hear and occasionally see him.

The clock showed a couple of minutes past 7:00, and nothing had happened, when suddenly our guard shouted, "Who goes there?" while swinging his submachine gun down and pointing it towards us. I shot at him immediately, and the others followed. I don't think we hit him, but we moved towards the west side of the factory, where we climbed over the fence via a shed. Then we covered each other with fire while advancing towards our assigned bunker to neutralize any guards who might have reached it. When I was about twenty meters from our bunker, I saw a nose sticking out through the rear opening. I fired instantly and hit the frame, but then the person shouted, "Don't shoot any more, Knud!". It was one of my own men; he wasn't hit. Incidentally, we all wore a white cloth around our necks so we could recognize our own people.

As soon as we opened fire, the other teams also began their attack. The guard in front of the gate had been neutralized, and the team had thrown a hand grenade through the window of an apartment on the factory's first floor. A German engineer lived there, whom we knew was armed and had a telephone. The apartment caught fire, and both he and his wife came rushing out, shouting for us to put out the fire. "What the hell, do you think I'm a fireman?" replied Johnny, one of my group leaders. The personnel in the guardhouse surrendered after brief gunfire. They shouted for mercy, came out with their hands up, and were rounded up.

Approximately 25 minutes had now passed since we started the attack. I had moved around to the back of the guard building to see if there were more guards inside. When I cautiously looked in through a window with my submachine gun ready, I found myself staring straight down the barrel of another submachine gun. I stared deeply into the eye behind the gun, ready to shoot, when I realized it was Brandt looking in from the other side of the building. We then sent for the trucks carrying the explosives. They drove in from the road at the south end of the factory, where we disarmed and searched the guards who had surrendered. Suddenly, a guard sprang forward with a pistol in his hand, heading straight for the trucks. I shot him down with a couple of bursts from the hip. We had planned from the outset to shoot all the guards, as they were Sommer people, marked for execution. But we couldn't bring ourselves to shoot people who had surrendered.

We then placed 3 bombs in each of the two large factory buildings. A total of 175 kg of powdered TNT. In each building, the three bombs were interconnected so they would detonate simultaneously. When we finished placing the bombs, the signal was sent to the covering groups, who began withdrawing towards Roskildevej. South of the factory, towards the Western Ramparts, we had positioned a group with a machine gun tasked with stopping the German post on the ramparts. But they never appeared. A couple of kilometers south of the factory, a group of our miners had mined the road to delay any German rapid reaction force from Avedøre Barracks, but none came from there either. The explosive charges were detonated, after which we drove away in the two trucks and 5 cars amidst endless cheers from the many hundreds of Danes who had been stopped at a safe distance from the factory by our covering groups on Roskildevej. Two of our cars couldn't start after the action; they had likely been hit during the firefight.

One group of our covering men commandeered a bus to get away. With this group was Dr. Hagens, who had participated in the action to tend to any wounded. Hagens drove the bus, but when they passed the Carltorp factory, guards there, also Sommer people, opened fire on the bus and hit Hagens, who was killed instantly. Our men returned fire, and one of them managed to straighten the bus out and drive away. It was a sad end to an otherwise highly successful action. Hagens had always been ready to help us in any way. It was the irony of fate that he, who was there to patch us up, became our only fatality. We had otherwise expected casualties to be unavoidable.

After receiving the news about the guards shooting at our men, we regretted that we had been soft-hearted towards the guards at Globus and had let them escape with their lives. The Normandy Invasion began that day, but that was pure coincidence; we knew nothing about it, though it naturally boosted the morale of both participants and onlookers. A couple of days after the action, we received a telegram from General Eisenhower's headquarters:

Congratulation to Danish saboteurs reference Grundahl Hansen S.H.A.E.F.

Grundahl Hansen was the owner of Globus.

The Germans responded immediately with a series of executions of resistance fighters and bans on taxi travel, etc. Planning such an action was a major and extensive undertaking. It wasn't done by a staff or by leaders, but in collaboration. For smaller actions, it was normal for the group itself to plan its own action, get it and the action plan approved by the leader and the sabotage committee, and then carry it out. If the action was larger in scale, planning happened in collaboration with the section leader and possibly other groups. Often, the target was chosen by the group itself because it had knowledge of it, either through group members or other contacts.

This local knowledge was crucially important for sensible planning. For security reasons, as few people as possible were involved in the planning. Often, group members were only briefed about their specific tasks immediately before the action or on the way to it. We had no radios, so communication during the action itself was by shouts and signals, and therefore difficult. It should be limited to the absolute minimum necessary, but difficulties often arose during the action that required changes, placing great demands on foresight in planning and on all participants understanding the attack plan and being able to act independently. But even with collaboration, it was often necessary for the leaders to intervene during the action and for participants to follow orders.

The Sommer Corps was a short-lived collaborationist unit formed in 1944 and comprised mostly of returning Danish Waffen-SS war criminals from the eastern front. They were named after their leader, the Danish Nazi fighter pilot Poul Sommer and were tasked with guarding the military installations of the Luftwaffe as well as factories supplying the German airforce.