In front of you is a photograph taken during a war, showing a large tunnel hall with rows of small jet fighters arranged beneath electric lights, along with a caption that names a place that does not appear on any map. You are probably wondering where this location was, who manufactured those aircraft, and what the picture fails to show. This guide gives answers to all three questions, beginning with the unpleasant truth that the planes in those halls were not made by free workers.
The Short Answer
By 1944, Germany’s aircraft industry was running on forced labor. Heinkel, one of the country’s biggest manufacturers, drew on concentration camp prisoners both at its home turf near Berlin and in the underground factories built to hide production from Allied bombers. The Oranienburg works, which sat beside the Sachsenhausen camp, is the clearest example of the link between a famous aircraft maker and the SS camp system. The underground He 162 plants in Austria and central Germany are a late-war continuation of the same logic.
Why Heinkel and Sachsenhausen Belong in the Same Sentence
Heinkel established a large factory in Oranienburg in the late 1930s, and the Sachsenhausen camp operated nearby. For the SS, this proximity was a business opportunity, since industry could draw labor from the camp. For Heinkel, however, workers could not leave, could not bargain, and could be replaced.
Prisoners from Sachsenhausen were either marched or transported to work in aircraft assembly and other connected jobs. Conditions were harsh, and the system treated people as a resource to be used up. If an aircraft plant was made a priority target, the prisoners were bombed together with the machinery, usually without the shelters which the German staff had access to. The Allied attacks on Oranienburg in 1944 and 1945 dealt a heavy blow to the factory and the area surrounding it, and this is one of the reasons why the account of the plant is also an account of how the air campaign transformed the economy of forced labor.
If you are researching this seriously, treat Oranienburg as the anchor point. The Sachsenhausen Memorial and Museum sits on the site of the camp, and its exhibitions cover the industrial exploitation of prisoners in far more detail than any photograph caption will.
The Underground Move: Why Factories Went Into Mountains and Mines
When the bombing campaign had made surface factories unsafe, the German planners decided to move production underground. Salt mines, tunnels, and caves were appealing because they were cool, dry, and hard to hit. Anyone looking at the pictures now reacts much the same way, mixing fascination with disbelief at the scale. A reasonable reaction is to consider the inconvenience of transferring the whole aircraft industry below ground; this was extremely costly, and it demonstrates how effective the bombing had been in forcing Germany to spend its resources on survival rather than on production.
Two underground sites matter most for the He 162 jet fighter.
Hinterbrühl, Austria. South of Vienna, a former gypsum mine with a flooded cavern called the Seegrotte was converted into an aircraft factory. Prisoners from a Mauthausen subcamp were forced to work there. The site is now a visitor attraction where you can walk into the mine and take a boat ride on the underground lake. If you go, treat it as a place of forced labor first and a novelty second. The guides cover the history, and it is worth asking specifically about the prisoner workforce, because the boat ride can easily flatten the story into a curiosity.
Tarthun and Egeln, Germany. A photograph circulated for years with a caption describing a large underground factory captured in April 1945 near “Engels, Germany.” There is no Engels in Germany. The only Engels most people know is in Russia. The caption almost certainly contains a typo for Egeln, a small town in Saxony-Anhalt, and the salt mine in question is in nearby Tarthun. If you have been searching for the location and finding nothing, that single letter swap is the reason. Searching for Egeln and Tarthun together gets you to the right history quickly.
Want to learn about another major work site where Sachsenhausen prisoners were exploited? Read The Klinkerwerk at Sachsenhausen: The Brickworks Prisoners Feared as a Death Detail to understand the brutal conditions prisoners faced there.
Who Actually Built Those Jets?
The honest answer is that nobody can give you a headcount from a photograph. A common assumption is that Jewish prisoners staffed the assembly halls, and that many people died because they could not work fast enough. The conditions of forced labor in these mines, with starvation rations, exhaustion, disease, and violence, certainly killed many workers. Workers in these programs came from a variety of backgrounds: prisoners of different nationalities and categories, foreign civilian laborers, prisoners of war, and German employees who held supervisory and technical positions. One must be careful when making broad statements; the only documented facts are the cases of forced labor and the number of deaths it caused; the precise makeup of any one hall at any one time can only be determined from the records of the camp and the factories.
Prisoners Salvaging Downed Aircraft
Forced labor did not end at the assembly line. Prisoners were also used to recover and break down crashed Allied bombers such as B-17s and B-24s so that metal and equipment could be reused. This fits the broader pattern. As raw materials ran short and raid numbers rose in the last two years of the war, every available resource, including human beings under SS control, was pushed into the salvage and production cycle. Descendants of bomber crews sometimes recognize a specific aircraft in the photographs that circulate online, and researchers who specialize in these records can sometimes help trace what happened to a particular plane.
What About the “Nazi Flying Saucer” Stories?
If, in your search for Heinkel’s underground factories, you came across claims regarding secret saucers, antigravity, Antarctic bases, and recovered alien spacecraft, then here is a realistic account of the matter. No credible evidence supports any of those claims. Wartime propaganda, postwar myth-making, and subsequent hoaxes have blurred the record. Some well-known ‘saucer’ photographs resemble ordinary heater and lantern cowlings from that period. The actual, documented story is in fact more astonishing in a far more disturbing manner: ordinary industrial companies had used a system of forced labor to build conventional weapons all the way up to the very last weeks of the war.
Did Heinkel Influence Japanese and Soviet Aircraft?
Heinkel did sell aircraft and technology abroad, and it had a long relationship with Japan. The He 100 and He 112 were purchased, and the engineer Fred David, an Austrian Jew, worked for Heinkel and later in Japan. Still, be careful with the word “influenced.” Japanese designs like the A5M came from Japanese designers, and the Ki 61 program was ordered before the He 100 even arrived. The most defensible point is smaller: engine mounting solutions for the license built DB 601 engine. The claim that Japan copied German designs has its roots in prewar prejudice about what Japanese engineers could achieve. Most aircraft of the 1920s and 1930s influenced each other, so crediting any single source is rarely accurate.
Want to understand how forced labor extended beyond Sachsenhausen’s main camp? Read Sachsenhausen’s Satellite Camps: How the Camp Extended Far Beyond Its Main Walls to learn how prisoners were deployed to work at sites across the surrounding region.
FAQs
- Where is “Engels, Germany,” the underground He 162 factory?
It does not exist. The name appears to be a mistake for Egeln in Saxony Anhalt, and the salt mine involved is at Tarthun, near Egeln.
- Were concentration camp prisoners really used to build and salvage aircraft?
Yes. Prisoners worked in aircraft production, including at Heinkel’s Oranienburg works beside Sachsenhausen and in underground sites like Hinterbrühl. Prisoners were also used to dismantle crashed Allied bombers for salvage.
- Was the He 162 mostly made of wood?
No. It used more wooden parts than many fighters to save strategic metals, but it was not a wooden aircraft like the Mosquito. The real weakness was the lack of proper adhesives late in the war.
- Was the He 162 designed to be flown by Hitler Youth?
No. That idea came after the aircraft was approved for production and reflected late-war desperation. It was never a design requirement.
- Could the Me 262 have changed the outcome of the war?
Many people argue that earlier development would have extended the fighting, since the jet appeared in prototype form in 1942 and Hitler pushed for a bomber role instead of a fighter role. Yet it would not have solved the larger problems of fuel, materials, and the collapse of German industry, and a faster jet program would have meant even more forced labor, not less.
