Robotic Teams Retrieve Abandoned Munitions from Baltic Waters

In the picturesque area of the Bay of Lübeck, visible from the rugged coastlines of northern Germany, dedicated removal squads are scouring the ocean bed. They're hunting not for the typical haul that local fishers steer clear of but for abandoned military ordnance. This includes sea mines, torpedoes, piles of artillery ammunition, and large bombs from aircraft, all languishing underwater for almost eight decades.

Throughout September and October 2024, submersible robots equipped with imaging devices, intense illumination, and detection technology have been actively searching for World War II-era munitions intentionally submerged in this area of the Baltic Sea. Specialists stationed on a nearby floating platform, cautiously positioned over the submerged weapons cache, evaluate and categorize each piece of ordnance. They then utilize the robots' electromagnetic attachments or a mechanical arm from a hydraulic digger on the platform to securely relocate the explosives into bin-like receptacles, which are then firmly closed and stored.

Massive quantities of German weapons were quickly submerged in the ocean following World War II, as directed by the Allied forces. Their aim was to eliminate the stockpile of Nazi armaments, along with some of their own, in the most expedient and cost-effective manner. Fishermen were compensated based on the amount of cargo they disposed of at specific locations designated for dumping, yet a significant amount of explosives and munitions ended up scattered throughout the bay, indicating a rush to complete the unpleasant task. The majority of this disposal activity took place from 1945 to 1949.

"Germany's Environment Minister, Steffi Lemke, emphasized to reporters during an October 2024 visit to the bay that the concern is not about a handful of undetonated explosives. Instead, the issue at hand involves millions of World War II-era munitions that were discarded by Allied forces to stop any potential rearming."

Last year's cleanup operation was a pioneering initiative aimed at addressing the hazardous remnants of conflict. Numerous disposal sites pepper both the Baltic and North seas, where it's commonly believed that around 1.6 million tons of military ordnance were abandoned in the waters of Germany. The majority of the discarded materials were traditional armaments, but the sea also became the final resting place for thousands of tons of chemical munitions, including chlorine and mustard gas shells.

For years, the issue of waste disposal sites received minimal focus, with many experts and officials believing that the dangerous substances would either stay contained within their deteriorating encasements or spread out harmlessly if leaked. "They claimed it wasn't an issue, believing everything would just dilute over time and lead to no adverse effects," states Edmund Maser, a toxicologist at the University Medical Center Schleswig-Holstein in Kiel, situated by the German Baltic Sea shore. Rare yet alarming events—such as Danish fishers being severely harmed by catching mustard gas ammunition, or holiday-goers getting burns after picking up moist lumps of white phosphorus, thinking it was amber—were viewed as regrettable but isolated risks.

Recent investigations have revealed that the environmental risks associated with underwater explosives might have been underestimated, posing an ongoing threat. The corrosive nature of the Baltic Sea's salt water has led to the deterioration of explosive casings, directly releasing harmful substances such as TNT into the water. Maser and his team have discovered traces of TNT in both mussels and fish near disposal areas, confirming the detrimental impact these chemicals have on sea life. Their research indicates that fish residing in proximity to sunken warships exhibit significantly increased incidences of liver tumors and damage to their organs.

"Traditional weapons have been identified as cancer-causing, while chemical weapons not only cause genetic mutations but also interfere with enzyme functions among other effects, clearly impacting living beings," explains Jacek Bełdowski, a foremost authority on the subject of submerged weapons disposal at the Polish Academy of Sciences. Studies conducted by Bełdowski and his colleagues have revealed that pollutants from underwater weapon deposits extend far beyond previously understood boundaries.

Aaron Beck, a marine chemist affiliated with the GEOMAR Helmholtz Centre for Ocean Research in Kiel, reminisces about a revealing 2018 research expedition that journeyed from Flensburg, close to the Danish boundary, to the German isle of Rügen: "We likely gathered thousands of water specimens, and astonishingly, in approximately 98 percent of those samples, we detected explosives. The pollutants were widespread."

Currently, Beck mentions that chemical concentrations in the water remain relatively minimal, attributing this to the majority of the munitions remaining sealed. However, without intervention, the risk of significant underwater pollution escalating in the near future is high.

Surge in Attention

Historically, bomb disposal units were summoned solely to address immediate threats, such as explosives found on beaches, or to prepare sites for new developments. The uptick in below-the-surface infrastructure projects, including offshore wind farms, gas conduits, and cables for internet and power, has led to an increase in demand for skilled experts to tackle the widespread issue of ordnance in the waters surrounding Germany. Yet, the largest dumping grounds often remain undisturbed by these development efforts due to the potential for project delays, escalating costs, and heightened dangers, leaving the most severe aspects of the ordnance problem unaddressed.

In July 2024, several waste management firms began probing the vast landfill located in the Bay of Lübeck, supported by a €100 million ($105 million) investment from the German government. The objective of this initiative is to develop a method that can effectively and extensively remove underwater munitions, with the goal of automating a significant portion of the operation. This would involve using drones to chart the locations of the dumps, followed by the organized recovery and safe elimination of the hazardous munitions.

The company SeaTerra, known for its expertise in disposing of munitions, was selected to conduct salvage operations for explosives at two underwater dump sites in a bay area. Working in collaboration with Eggers Kampfmittelbergung, another firm specializing in ordnance clearance, they successfully retrieved approximately 10 tons of small-caliber munitions and 6 tons of larger explosive devices over a two-month period in 2024. However, the significant amount of ordnance recovered wasn't the primary focus of the mission. Instead, the objective was for these companies to test their technological capabilities, gather valuable data, and prove the viability of such salvage operations.

In Germany, the frequent discovery of undetonated explosives is a significant issue, leading to the establishment of a dedicated, full-time bomb disposal unit tasked with neutralizing these dangers, often found during building endeavors. However, addressing similar threats in maritime environments has traditionally been a challenging and costly process, relying heavily on the efforts of divers to locate and retrieve these munitions for onshore disposal by German bomb disposal teams. Consequently, the idea of leveraging advanced technology to efficiently remove sea-based ordnance, previously deemed too difficult and expensive to undertake on a large scale, is now gaining appeal.

At SeaTerra, the operations are directed by Dieter Guldin, a 58-year-old professional archaeologist characterized by his somewhat disheveled hair and a scruffy beard, who shifted his career focus to ordnance disposal after many years. Originally, Guldin managed excavations of historical sites until he teamed up with a friend from his younger years at SeaTerra. Initially, he aimed to establish a venture in marine archaeology, but eventually, he transitioned to the financially rewarding and dynamic field of bomb disposal.

Guldin points out that German aquatic territories are widely affected, with certain areas harboring dense clusters of ancient explosives posing immediate threats to the environment. His advocacy contributed to the initiation of a government-supported initiative. Anticipating success, he invested SeaTerra's funds in advance, procuring cameras and tailoring the equipment to meet specific requirements, all before confirmation of the project's approval was received. Fortunately, their project received official authorization to move forward.

Leif Nebel, the managing partner at Eggers Kampfmittelbergung, has shared that their team is currently involved in extensive scanning of munitions and developing artificial intelligence programs alongside a comprehensive database. "Our goal is to enhance our ability to quickly and accurately identify what a suspected item might be, particularly when it comes to munitions found underwater," he explained. This information is critical for disposal teams who, for safety reasons, must ascertain the amount and type of explosive material they are dealing with. This ensures that the detonation chamber used in the disposal process is capable of handling the material safely and helps predict how the ordnance might react, such as the possibility of a fuse triggering an explosion.

The subsequent phase of the ongoing pilot initiative involves the construction of a floating facility designed for the disposal of old munitions by incineration, situated close to the disposal sites themselves. This approach would negate the necessity of retrieving the ordnance from underwater, transferring it to land, and then conveying it across the country to Germany's main disposal site, located in a complex near Münster, close to the Dutch border. Transporting the munitions in this manner is not only costly and fraught with risk, but it also presents considerable regulatory hurdles. This is because, according to German law, transporting hazardous old munitions is only permissible in cases of emergency. Furthermore, the disposal facility near Münster is already struggling to cope with the influx of bombs being discovered at various construction sites nationwide.

The appearance of the floating structure remains uncertain, as does its capacity to process explosives through its blast furnaces. Larger ordnance, such as naval mines and air-dropped bombs, may require disassembly prior to insertion. Additionally, the cumulative explosive force of the materials fed into the furnace must not exceed a specific limit to avoid detonating the structure itself.

In the future, the goal is to deploy autonomous submersible vehicles to explore, chart, and conduct magnetic surveys of the ocean floor to understand its contents. Specialists, with the assistance of artificial intelligence systems trained on vast amounts of data from previous clearing operations, would analyze these scans to accurately and securely recognize the debris scattered on the ocean bottom. Mechanical arms and containment units would then collect these explosives, place them in sealed, labeled containers, and organize them in specific holding zones for eventual disposal, reducing the reliance on human divers for such tasks.

In my conversation with Guldin in December, following the completion of the initial phase of the pilot program, he outlined a potential future scenario for this project. He envisioned using autonomous robots fitted with imaging devices, intense lighting, sonar technologies, and advanced gripping tools for more effective munition retrieval than the current crane-based methods, and these robots could work continuously. Moreover, utilizing unmanned vehicles could allow for the simultaneous clearance of disposal areas from various angles, a feat unachievable with stationary platforms on the water's surface. Additionally, experts in ordnance, who are currently in limited supply, might be able to manage the majority of operations from a distance, working out of offices in Hamburg, rather than spending extensive periods on the ocean.

The concept of remotely handling underwater tasks might not be fully realized yet, due to challenges like limited visibility underwater and occasionally insufficient lighting, which complicates operations via live feeds. However, initial trials have shown that the majority of the technology meets expectations to a certain extent. "There's definitely potential for enhancements, but at its core, the approach is effective, especially the process of directly identifying and relocating underwater items into transport containers," explains Wolfgang Sichermann, a naval architect from Seascape, the company managing this initiative for the German environmental ministry. The goal moving forward is to design and construct a sea-based disposal facility in the near future, with aspirations to start destroying the first underwater explosives by around 2026, according to Sichermann.

Touch Forbidden?

During my trip to the SeaTerra barge on a brisk yet sunny day last October, I had the opportunity to converse with seasoned ordnance disposal professional Michael Scheffler. He had been stationed for a month on the vessel, anchored near Haffkrug along the German shoreline, meticulously opening mud and slime-encrusted heavy wooden boxes filled with 20-mm cannon ammunition produced by Nazi Germany. By the morning of my visit, they had already inspected roughly 5.8 tons of these 20-mm projectiles, which had been retrieved from the seabed using mechanical claws and aquatic drones before being transported onto the vessel.

For many years, Scheffler has dedicated his career to the disposal of munitions, starting his journey in the German armed forces. However, it wasn't until recently that he truly understood the magnitude of the issue regarding discarded munitions, nor had he considered addressing the issue in an organized manner before.

"In my 42-year career, this is the first time I've encountered a project of this magnitude," he shared with me. "The innovations and research emerging from this pilot project are incredibly valuable for what's to come."

Guldin shares a hopeful view on the outcomes of the trial but cautions that technology's capabilities for remote operations have their boundaries. Tasks that are complex, perilous, and delicate will occasionally necessitate direct human intervention for some time yet. "There are limitations to fully remotely clearing the seabed. Certainly, the presence of divers and EOD [explosive ordnance disposal] experts working underwater, along with specialists physically present, is irreplaceable and here to stay."

Should the initial cleaning operation be effective, there is optimism that this technology could attract buyers from beyond the Baltic region. Until the late 1970s, global military forces commonly used the seas to dispose of outdated munitions.

However, the lack of profit in destroying old air-dropped bombs means that any increase in the disposal of sea-dwelling explosives would require significant funding towards environmental cleanup, an occurrence that is infrequent. “Certainly, we could make the process quicker and more effective,” Guldin notes. “The problem is, bringing additional resources to the effort implies someone has to foot the bill. Are we expecting a future government that's prepared to cover these costs? I'm skeptical, to say the least.”

"Sichermann mentions a recent conversation with the Bahamian ambassador, who extended an invitation for cleanup efforts of materials submerged by the British in the 1970s, just before the Bahamas gained its independence. The catch, he noted, was the expectation for Sichermann to not only provide the technological means but also the necessary funding. This underscores the importance of securing financial support for such initiatives, Sichermann adds. With the right investors on board, he believes there's a vast amount of cleanup opportunities globally due to the abundant presence of discarded munitions."

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