Grimberg 3/4

Cuckoo

A Coal Mine in the Shadow of the Past

The Grimberg 3/4 mine complex in the Weddinghofen district of Bergkamen (located on Schulstraße) was a central pillar of the Monopol coal mine for decades. Commonly known simply as “Kuckuck,” this site stands, like almost no other in the Ruhr region, as a symbol of technological excellence, profound structural change, and the greatest tragedy in German coal mining history.

Structure and Development

The history of the site began in July 1923 with the sinking of Shaft 3. Following delays due to economic factors and a water inflow, the facility was extensively expanded starting in 1934 under the Essener Steinkohlenbergwerke AG and supplemented with the Grimberg 4 ventilation shaft. Regular coal production began in 1936. The facility was considered state-of-the-art underground; innovative large-scale equipment such as the coal planer was tested here at an early stage, which also attracted international professional interest to the site.

The 1946 Mine Accident

The mine gained historical notoriety as the site of the worst mining disaster in the history of German mining. On February 20, 1946, a devastating firedamp and coal dust explosion occurred at a depth of nearly 1,000 meters. The force of the explosion was so immense that the shaft hall above ground collapsed and a 300-meter-high jet of flame shot out of the shaft. Of the 466 miners on the early shift, 405 lost their lives—including the mine director and three British officers from the Control Commission. Subsequent generations kept the memory alive through memorials such as the one at the Waldfriedhof cemetery in Weddinghofen.

Modernization, Integration, and Decommissioning

Despite the destruction, the site was rebuilt. After being temporarily shut down, Shaft 3 was re-sunk in 1952. In 1972, as part of a restructuring process, the facility became the property of Ruhrkohle AG (RAG) and was renamed Haus Aden 3/4. Mining operations at Grimberg 3/4 ended in 1973; thereafter, the site continued to serve as a hoisting, material, and ventilation shaft for the Haus Aden main coal mine. In 1989, Shaft 3 reached a final depth of 1,638 meters and was thus considered, for a time, the deepest shaft in Europe.

In 1994 and 1995, the shafts were permanently shut down and backfilled in sections. The above-ground demolition of the distinctive surface facilities and mine towers was completed by 2003, so that today only Protego hoods for mine gas venting and a memorial stone erected by the local miners’ association serve as reminders of the former large-scale mining complex.

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Dangers of Mining

Health and Safety in Mining

Historically, underground coal mining was associated with extreme risks to life and limb. The path toward modern occupational safety in the Bergkamen mining district was a process that spanned decades, driven by technological progress, government regulations, and the lessons learned from major disasters.

Hazards in Non-Mechanized Operations

In the late 19th and early 20th centuries, underground work was primarily characterized by extremely hard physical labor. Technical aids were largely absent. Miners were exposed to acute dangers such as cave-ins (“coffin lids”), water inrushes, and unsafe rope descents. Toxic or explosive gases posed an invisible risk. To protect themselves from carbon monoxide and mine gas, miners initially used canaries’ heightened sensitivity as a biological early-warning system, before kerosene safety lamps and, later, ventilation systems became standard.

Technological Advancement and Major Disasters

As mechanization increased starting in the 1920s, the risks changed. While the introduction of jackhammers and drills increased efficiency, it also led to massive dust generation. “Dust lung” (silicosis) became a chronic occupational disease affecting generations of miners.

At the same time, devastating mass accidents in the mining region led to a drastic rethinking of safety policy. The worst mining disaster in the history of German coal mining occurred on February 20, 1946, at the Grimberg 3/4 mine in Bergkamen (part of the Monopol mining complex). A firedamp and coal dust explosion claimed the lives of 405 miners. This disaster forced the introduction of stricter safety regulations, improved dust suppression methods, and the mandatory provision of modern respiratory protection and rescue equipment.

Modern Prevention

During the final decades of active mining, up until the closure of the Haus Aden coal mine in 2001, occupational safety evolved from reactive hazard control to systematic prevention. Automated gas monitoring systems, improved hydraulic support for the mine tunnels, and comprehensive occupational health care reduced accident rates to an all-time low.

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Training

Training in the Bergkamen District

With the advent of coal mining in 1890, the rural communities in the Bergkamen area underwent rapid transformation. Through the merger of the mining shafts into the Haus Aden coalfield, the area developed into one of Europe’s largest mining towns in the late 20th century. This massive boom was inextricably linked to a highly specialized, local educational infrastructure.

The coal mines' training workshops

The systematic training program was directly linked to the major coal mine sites. Both the shaft facilities at the Monopol Mine (Grillo/Grimberg) and the Haus Aden Mine—which was built starting in 1938—maintained their own training workshops. Here, the apprentices learned the basic skills of woodworking and metalworking. This training met the enormous demand for skilled workers in underground operations and ensured compliance with strict safety standards in a highly dangerous work environment.

The Mountain Vocational School

The practical work was complemented by theoretical instruction. Bergkamen was home to its own mining vocational school. These institutions provided specialized knowledge in mine safety, ventilation, and machinery. In the course of subsequent structural changes, these educational institutions were centralized and transferred to joint organizations such as RAG-Bildung, which also offered training programs outside the mining sector.

The Historical Heritage

The closure of Haus Aden in 2001 marked the end of the era of active coal mining and, with it, the end of traditional on-site mining training. Today, historical collections and museum reconstructions—such as the training tunnel (“Barbara-Stollen”) in Bergkamen—preserve the region’s technical expertise and training traditions for future generations.

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The Mine Disaster

The Tragedy of 1946

On February 20, 1946, one of the worst disasters in German coal mining history occurred at the Grimberg 3/4 mine in Bergkamen. A mixture of methane and air had triggered a firedamp explosion. This, in turn, set off a coal dust explosion. The shock wave raced through the mine, shot up the shaft, and destroyed parts of the surface facilities. A meter-high flame was visible above the site.

At the time of the accident, 466 miners were underground. 405 of them lost their lives. Only 64 were rescued. The accident highlighted how poor safety conditions were in the postwar mining industry. Many facilities were in poor technical condition. Initially, coal production took priority over workplace safety. At Grimberg, there was an insufficient supply of fresh air. Gases and dust had accumulated unchecked. Respiratory protection equipment was virtually nonexistent. The mine rescue teams had only enough equipment to last a few hours.

It was not until after the disaster that regulations were revised. New rules regarding dust control, ventilation, and emergency equipment were introduced.

The miners’ training also fell short of requirements. While basic knowledge was taught, technical aids and binding standards were lacking. Many safety measures that are taken for granted today were only implemented as a result of disasters like this one.

Working underground also took a heavy toll on miners’ health. Many miners suffered from pneumoconiosis, hearing loss, and poisoning from mine gases. Life expectancy was significantly below average. Many died in their fifties or sixties as a result of their work.

The Grimberg 3/4 disaster marked a turning point in how safety and health were addressed in the mining industry. It brought home the risks associated with the profession and the immense responsibility involved in mitigating them.

Today, a memorial at the Waldfriedhof cemetery in Bergkamen commemorates those who lost their lives in the disaster.

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Documentation of the Accident

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Forced Laborers

Forced Labor Underground

During World War II, forced laborers—primarily from the Soviet Union—were put to work on the site. The men worked underground and on the surface—exhausted, malnourished, and under strict guard. Their living conditions were extremely harsh, and medical care was virtually nonexistent. Many succumbed to illness, malnutrition, and exhaustion. Their final resting places were gathered in one location outside the mine: what is now known as the Russian Cemetery. It is secluded, simple, and unadorned, yet every headstone tells the story of a life lost. The cemetery stands as a symbol of a forgotten history of suffering and is maintained so that the memories do not fade. Here, we remember the people who were forced to perform hard labor and whose fate has yet to be fully addressed.

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The Story