The Searcher

Fishing for Secrets in the Nord Stream Abyss

Erik Andersson on his private boat in the waters off the coast of Mollösund, Sweden, on June 17, 2023. Photo: Agnes Andersson

The skies over the Baltic Sea are a clear blue with just faint ribbons of clouds. It’s May 24 and Erik Andersson eats a bowl of yogurt for breakfast on the deck of the Swedish diving vessel Baltic Explorer. Between bites, the 62-year-old retired engineer and entrepreneur discusses the previous day’s work on his investigation into one of the most significant international crimes in recent history: the bombing of the Nord Stream pipelines.

“Well, we arrived at the site, it was the southern site, you know, the first bomb that exploded at 2:03 in the morning local time 26th of September, and we started by making sonar scans with the sonar sensors that are attached to the boat,” he says to the camera held by his daughter Agnes, who has joined him on the expedition to document his journey. “We’re scanning back and forth over the explosion site and by doing that, we got a three-dimensional depth profile. And we could map out, we could see immediately that that was the trench, 100 by 60 meters and 10-meter-deep trench, which was quite an interesting discovery. That’s what we were looking for. It’s almost like a photo of the crime scene. I think it’s the first time we have an accurate three-dimensional model of the crime scene.”

That evening, just after 5 p.m., Andersson stands inside the cabin of the Baltic Explorer behind the captain, watching a video monitor as the ship slowly maneuvers back and forth over a section of the Nord Stream 2 pipeline off Sweden’s coast. On the screen, sonar imaging comes into focus and reveals a hole in a pipeline on the seabed. Andersson jokingly calls this section of the pipeline the “holy grail” of his investigation because it is the only section of the three strands of the Nord Stream pipeline that was bombed but did not cause a massive gas rupture. That’s because it was no longer pressurized when the explosives detonated. This is significant, Andersson says, because on the other two bombed lines, the explosion caused the pipeline to break apart, making it impossible to see what the initial puncture wound from the bombs looked like.

Before the expedition, Andersson believed that if he could find the hole, then it would be the first time anyone outside of a government authority or the Nord Stream company had examined a bomb puncture in the pipeline from the sabotage. “What we want to see is really the primary impact of the explosives. And this site is the only site I think now where we have any hope to see that because all the other sites, there had been this enormous outflow of gas: natural gas that’s just blown away all the mud and all the traces that were of the original explosion,” Andersson explained. “It’s not so easy to find. We didn’t see it on the boat-mounted sonar, so we have to send down the fish,” the nickname given by the captain to the submersible sonar device. Eventually, using the “fish,” they managed to find their target.

“It’s on the seam,” says the captain in a matter-of-fact tone as Andersson stares at the sonar monitor.

“It’s right on the seam?” Andersson asks.

“Yeah,” the captain responds.

“Whoa,” exclaims Andersson. “It’s on the seam! It’s right on the seam! Yeah. So, this is the first evidence that they actually put the explosives on the seam. They knew about the seam. That must be the weak point.”

Andersson is not a professional investigator or a journalist, and his voyage was not sponsored by a government. By training, he is an engineer with a master’s degree in engineering physics. He had a successful career at Volvo and Boeing and worked on advanced programs used by commercial and military aircraft, including U.S. military aircraft. He had followed the developments of the Nord Stream bombing carefully, but it was not until journalist Seymour Hersh published his bombshell story alleging that President Joe Biden had personally ordered the destruction of the pipelines that he became obsessed with the mystery. The expedition to the bombing site grew out of that passion. Andersson freely admits that he was motivated by a desire to prove that Hersh’s narrative was correct. What he found was quite different.

AT SEA - SEPTEMBER 27: In this Handout Photo provided by Swedish Coast Guard, the release of gas emanating from a leak on the Nord Stream 2 gas pipeline in the Baltic Sea on September 27, 2022 in At Sea. A fourth leak has been detected in the undersea gas pipelines linking Russia to Europe, after explosions were reported earlier this week in suspected sabotage. (Photo by Swedish Coast Guard via Getty Images)

A handout photo provided by the Swedish Coast Guard shows the release of gas emanating from a leak on the Nord Stream 2 gas pipeline in the Baltic Sea on Sept. 27, 2022.

Photo: Swedish Coast Guard via Getty Images

A Forensic Investigation

On September 26, 2022, when a series of explosions rocked the Nord Stream pipeline in the Baltic Sea waters off the coasts of Sweden and Denmark, Andersson followed the news like everyone else. He says he didn’t see it as a massive geopolitical mystery or an event of much consequence beyond the potential environmental impact in the water. “It wasn’t like a big thing when it happened,” he recalls. “I found the media coverage fishy,” he said. “It was like they were downplaying it.” Initial news reports showed a pool of bubbling water caused by the discharge of gas in the sea. The possibility that the gas release was the result of a leak or other accident was quickly ruled out once the Danish and Swedish authorities did an initial survey of the site. And once the other bombs went off 17 hours later in multiple sites, there was no doubt. Government authorities swiftly concluded that an intentional act of sabotage had been carried out against a high-profile, profitable, and controversial international project controlled by Russia.

Andersson saw video clips circulating on Twitter that showed Biden and other U.S. officials appearing to threaten to take out the pipeline in the months before the attacks. “With all the history of the Nord Stream 2 and the motivation, I suspected that this was somehow a U.S.-sponsored action, I guess, but I wasn’t thinking much about that,” he said. Andersson had spent years working on jet fuel calculations for major airline corporations, and he was curious, on a scientific level, to hear details of how the pipelines exploded.

He was frustrated that very few technical details had filtered into the media. There were aerial images of the bubbling pools, but nothing showing the aftermath of the immediate impact. The first explosion had happened on the Nord Stream 2 pipeline off the coast of the Danish island of Bornholm at 2:03 a.m., so it is not surprising there was no active surveillance of the event itself.

“It was annoying me tremendously that the first footage was like 12 hours after. While in the immediate event, the gas plume must have been enormous and just the thought of what could have happened,” said Andersson.

The Nord Stream 1 and 2 pipelines each had two lines that stretched from northwestern Russia and under the Baltic Sea to northern Germany. On Sept. 26, 2022, three of the four lines were severely damaged in an act of sabotage. The first explosion occurred on Line A of Nord Stream 2 at 2:03 a.m. off the coast of the Danish island Bornholm. Seventeen hours later, off the coast of Sweden, three more explosions occurred, damaging both of the Nord Stream 1 Lines and a second section of Nord Stream 2 Line A. Line B of Nord Stream 2, the one closest to Russian territory, was the only line left undamaged.

Map: The Intercept

Sweden, Denmark, and Germany all launched investigations with the support of the United States. Divers filled shipping containers with underwater evidence and conducted marine video surveys and forensic analysis. Publicly, insinuations and accusations proliferated. The U.S. all but accused Russia of blowing up its own pipeline. Ukraine directly accused Vladimir Putin of responsibility. Open-source analysts began monitoring ship movement data and speculating about how Moscow might have done it. Putin charged that “Anglo-Saxon powers” were behind the attack. Some analysts speculated that Poland, the most aggressive supporter of Ukraine’s fight against Russia, may be the culprit. Given the larger context of the Russian invasion, Ukraine clearly had the strongest motive, but Kyiv steadfastly denied it had anything to do with the bombing.

Andersson tweeted some criticism of the government investigations of the incident, mostly focused on the lack of transparency. He also criticized media outlets for not uncovering more forensic evidence, despite the official pronouncements that the explosions were a deliberate act of terrorism and the possibility the sabotage was conducted or sponsored by a major world power. He found the secrecy disturbing. “There was no real information being shared with the public about the evidence that had been gathered or just sort of what exactly happened down there on a scientific or forensic level,” he said. “I think that when the government is so secretive, they’re feeding speculation and conspiracy theories.”

On February 8, Hersh published his story on Substack, charging that Biden had personally authorized the bombing of the pipelines and that U.S. navy divers had planted the bombs on the Nord Stream 1 and 2 pipelines during NATO’s BALTOPS 22 exercises in the Baltic Sea three months before they detonated. Russia publicly embraced Hersh’s story and introduced it as evidence of the need for an independent United Nations investigation into the attacks. The White House called Hersh’s report “utterly false and complete fiction.”

“When the government is so secretive, they’re feeding speculation and conspiracy theories.”

Andersson had never heard of Hersh, but when he saw journalists and commentators he admired on Twitter defending the 85-year-old reporter from the almost immediate deluge of attacks on his credibility by prominent media and political figures, as well as the denials from the White House, his gut instinct was that the right people were attacking Hersh. “I saw he had a lot of respect. I mean, this is a very experienced journalist, and he knows how to deal with sources, to evaluate his sources.” Andersson’s sense was that Hersh’s story was “probably true,” but he was mostly interested in the voluminous details contained in his report.

Soon, Andersson was spending his days and nights poring over every news story on the bombing that he could find, watching hours of news footage, and exchanging analyses with a wide cross section of people on Twitter, mainly accounts scouring the internet for open-source data that might shed light on who perpetrated the attacks and how. Andersson would engage both critics and supporters of Hersh and argue his case, ask questions, or share information. He eventually helped assemble an informal online war room with a handful of other amateur sleuths, and they publicly and privately compared notes and built on one another’s research. He also watched countless interviews Hersh did about his story, hanging on to every new detail that had not been in his original article, including an assertion that some of the bombs planted by the saboteurs did not detonate, leading to a scramble by the U.S. to remove the evidence.

At the beginning of his full-time obsession with the Nord Stream attacks, Andersson worked exclusively online. He began tinkering around with MarineTraffic, a service for monitoring the movement of ships and vessels and began reviewing all the data from the Baltic Sea to search for corroboration of various aspects of Hersh’s report. He also argued with open-source analysts aligned with the research group Bellingcat, whose network emerged as a leading force in trying to debunk (and mock) virtually every detail of Hersh’s story. Andersson often appeared in the Twitter feed of Oliver Alexander, a Danish researcher who has been particularly vicious in his denunciations of Hersh (he refers to him as “Senile Hersh”) to argue with him about his conclusions. He also discreetly joined Bellingcat’s Discord forum on the Nord Stream bombing and said it appeared to him to largely be a groupthink operation aimed at proving that Russia was behind the attack.

Andersson also began corresponding with some prominent scientists and researchers in Sweden, Denmark, and Norway, sharing his theories and analysis. Several leading researchers working to document the seismic activity caused by the Nord Stream blasts engaged in extended email exchanges with him, and some thanked Andersson for his insights and for pointing out discrepancies or errors in their data presentations.

On March 7, the New York Times and a consortium of German media outlets led by Die Zeit and ARD reported that U.S. intelligence and German law enforcement sources were investigating what they characterized as a “pro-Ukrainian” group suspected of being involved in the attacks. Neither story directly accused the Ukrainian government of involvement. The German reports identified a 50-foot sailboat, the Andromeda, rented in the Baltic Sea port town of Warnemünde by a company registered in Poland and owned by two Ukrainians. According to the reports, a team of six people, at least some of whom allegedly used fake passports, left a slew of evidence onboard, including explosive residue. Ukraine vehemently denied it had any involvement in the attacks. For his part, Hersh suggested that the Andromeda evidence had been concocted as part of a cover story to counter his exposé and draw attention away from the actual perpetrator, the U.S. government.

DRANSKE, GERMANY - MARCH 17: In this aerial view the Andromeda, a 50-foot Bavaria 50 Cruiser recreational sailing yacht, stands in dry dock on the headland of Bug on Ruegen Island on March 17, 2023 near Dranske, Germany. According to media reports, German investigators searched the boat recently and suspect a six-person crew used it to sail to the Baltic Sea and plant explosives that detonated on the Nord Stream pipeline in September of 2022, causing extensive damage. Investigators reportedly found traces of explosives on the table inside the yacht. While initial findings point to a possible Ukrainian connection to the sabotage operation, many questions remain open.  (Photo by Sean Gallup/Getty Images)

In this aerial view, the Andromeda, a 50-foot Bavaria 50 Cruiser recreational sailing yacht, stands in a dry dock on the headland of Bug on Rügen island on March 17, 2023, near Dranske, Germany.

Photo: Sean Gallup/Getty Images

Andersson grew tired of the online information wars and speculation based on publicly available data that he believed was subject to manipulation or biased interpretations. He had watched scores of documentaries and news reports about the Nord Stream attacks, including the handful of films featuring underwater footage of the damaged pipelines. He says he got the sense the journalists filming under the waters of the Baltic “were not guided by some forensic interest to figure out what was going on” and only filmed superficial footage of the crime scene. “There was no primary damage from the explosion anywhere, so there was nothing that could narrow down the number of possible narratives.”

In March, Andersson began looking for a captain with a ship willing to take him on his own expedition. Within days, he had contracted a vessel with Patrik Juhlin, a captain Andersson jovially described as a “cowboy.” Juhlin was an experienced and knowledgeable Baltic skipper willing to push the bounds of rules and regulations and cruise around in the international waters where multiple bombs had exploded. Andersson’s mission, he said, centered around “very simple objectives: the type, size, and placement of the bombs.”

Andersson spent $10,000 on the boat charter and another $10,000 on an underwater drone with a high-resolution camera and other equipment. He taught himself how to use the remotely piloted marine surveillance vessel, beginning in his backyard swimming pool and then eventually conducting tests off the coast of Gothenburg. He also wanted the ability to take sediment samples from the seabed, so he improvised a valve that looked like a high school science project. He used plastic cylinders and bicycle inner tubes to collect samples that might contain traces of explosives.

Andersson applied for permission from the Swedish and Danish authorities and was pleasantly surprised when they approved his request to conduct a survey. “It was perfectly legal and allowed to go there, but it was still prohibited by some sort of insinuation that we’re not supposed to do it,” he said.

Although Sweden, Denmark, Germany, the U.S., and Russia are all currently investigating the sabotage of the pipelines and are doing so with vastly superior equipment, resources, and access, Andersson was skeptical there would be any meaningful transparency from the national investigations — certainly not anytime soon. He had no hope that new organizations would do serious forensic investigations of the blast sites. “I think that there must be some competition if they are just sweeping the things under the carpet.”

Aboard the Baltic Explorer, Erik Andersson and his daughter Agnes monitor the video feed from an underwater drone over Line A of the Nord Stream 2 pipeline on May 24, 2023.

Screenshot: The Intercept, Video: Agnes Andersson

The Engineer

If you look at Erik Andersson’s CV, it paints an impressive picture of a successful entrepreneur and inventor. Early in his career he worked for Volvo, before his work caught the eye of major airline corporations and he negotiated the buyout of a program he had developed. He helped start a new company where, as chief technology officer, he oversaw the development of software for major airlines. Eventually, the firm was acquired by Boeing subsidiary Jeppesen in 2006 for $100 million. Andersson wanted to continue working for Boeing, so he stayed on as an engineer. “I worked on trajectory optimization and aircraft performance modeling. I learned a lot about flight physics and forces generated by accelerating gas masses,” he said. “Some of this general knowledge has been useful to me in the Nord Stream investigation.”

In 2016, he left Boeing and retired, though he continues to work on a variety of projects, including a teak wood harvesting plantation on a rainforest he manages in Brazil. How he came to own a majority share of that business is a story unto itself, but it centers around Andersson allegedly getting swindled out of $1 million by a Swedish politician and businessman. He aggressively fought back against the fraud, a battle that was covered by Swedish media. The politician denied any wrongdoing, but Andersson emerged from the battle with a majority stake in the business.

When you talk to Andersson or look at his social media feeds, you quickly encounter two major strands of his personality. Clearly, he has a sharp scientific and analytical mind. He researches his hypotheses extensively and tries to use solid scientific and mathematical approaches to proving or disproving them. He readily admits when he is wrong, though he first stubbornly exhausts all possibilities that he might be right. He engages in lengthy and detailed email exchanges and conversations with scientists and government officials in Sweden and elsewhere.

“I think it’s a healthy thinking process to create narratives and then look for confirmation as long as you are aware that’s what you are doing, and you’re ready to say you were wrong if the evidence says so,” he argues. “If you pretend to be ‘objective,’ you are much more likely to be fooled by your biases, I think. It’s also much easier to change your mind if you go all in for some narrative until you are exhausted and done with it.”

But there is another aspect to Andersson that would seem to contradict his scientific disposition, and that is his enthusiasm for a mishmash of fringe theories about Covid-19, the 2020 presidential election in the U.S., and other dubious narratives popular in MAGA world. He admires Donald Trump; disparages climate crisis activists; and retweets dubious theories about Anthony Fauci, Covid, and China. Andersson said he liked many of Trump’s campaign pledges, including on immigration, deregulation, and pulling back from foreign wars. He also supported Trump’s posture toward Putin and Russia.

Andersson didn’t just watch the Trump campaign. He logged onto a betting marketplace in October 2015 and saw that oddsmakers were offering 18 to 1 odds, so he placed an initial bet of 100,000 Swedish krona, a bit more than $12,000 at the time, that Trump would win in 2016. When he woke up the morning after the election, he was 2.5 million Swedish krona — or $300,000 — richer. “I should have put up a third of my fortune, the optimal bet, which should have been bigger. So, it was a small bet. I was very conservative.”

Andersson was elated when Trump won and said he wished Sweden could have a leader like Trump. Mostly, though, he was excited that a bombastic outsider might shake up the system in the world’s most powerful nation. “I was interested to see what would happen. You know, it’s like a big sledgehammer coming in.”

Perhaps it was his fascination with such counter-narratives that led him to believe so fervently in Hersh’s account of the Nord Stream bombing. But unlike many social media warriors, when confronted with empirical evidence that refuted his hypothesis, he changed his position.

Andersson retrieves soil samples taken near Line A of the Nord Stream 2 pipeline to test for explosive residue on May 24, 2023.

Screenshot: The Intercept, Video: Agnes Andersson

Andersson began his investigation onboard the Baltic Explorer on May 22 and declared his mission an act of “popular oversight.” If governments, especially those whose allies may be responsible for the attacks, “can control all the evidence and then tell a story and expect us to take it at face value, that’s not how the system should work.” He said he wanted to prove that private investigations of major world incidents could serve as a guardrail against media outlets spinning false narratives or governments covering up crimes. “This is no criticism of [lead prosecutor] Mats Ljungqvist and the Swedish investigation. I see signs that they might actually do a good job,” he said. “It’s more a general observation from similar cases that a certain amount of citizen oversight is good to help authorities to not abuse their control of information.”

For three days, Andersson’s vessel traversed the crime scene in the Baltic Sea, and he created extensive sonar maps of each of the blast sites. He filmed the damage from the explosions and the sites where sections of pipelines ruptured. In the case of one section of Nord Stream 2, which was punctured by a blast but did not explode because it had been depressurized, he captured what appears to be the only private footage of primary damage from an explosive device used in the bombing. He discovered craters from gas explosions and found evidence suggesting that the bombs had been dug into the mud, indicating that divers, not drones, likely placed explosives under or along the lines. “I felt that the Swedish investigator sounded very credible when he said that this could only be done by big state actor. And I don’t really see that now,” Andersson said. He also believes his research shows that it is unlikely a marine drone or other underwater vessel was used to plant the bombs, as has been suggested by analysts who believe Russia carried out the attack. “I think it would be very difficult to place the bomb under the seams with a remote-operated vehicle and do the variety of tasks of digging a hole and putting it in in there. It was a slab that you dig down next to the pipeline. I think a diver could have done it in a very short period of time.”

Hersh has been adamant that the bombs were placed by American divers and that it was a highly complex task necessitating not only U.S. Navy specialists, but also the support of Norwegian maritime forces. Some analysts, including Hersh, have also suggested that the 80-meter dive could not have been accomplished from a sailboat, such as the Andromeda, which has been connected by German law enforcement to the operation.

“Totally false,” says Peter Andersson, an executive at Poseidon Diving Systems, a Swedish company that provides advanced diving equipment to militaries around the globe, including the U.S., Germany, and Sweden. A world-class diver who travels the globe teaching military and civilian diving instructors to use Poseidon’s equipment, Peter (no relation to Erik) says he personally knows at least 30 divers in Sweden alone who are capable of such a dive. “It’s very common in Germany, very common in the U.S. and so on around the world doing these kinds of dives. I could easily do this, no problem,” he said. “You don’t need to be super experienced, but for a military diver or a paramilitary diver, it is no problem at all.”

Peter Andersson, who estimates that he has personally done several hundred dives in the Baltic Sea, said that if the divers dispensed with traditional safety precautions and backup equipment and used underwater propulsion devices to descend to the pipelines, the entire sabotage mission would be achievable in a matter of hours with two divers and a support crew. “In the case of doing this, bending all the rules, don’t care about security, don’t care about having bailout tanks that we normally have, if you’re in a war mode, you can easily go down with the machine,” he said. “Of course, if something happens, they will never find you. But I think that in this case, putting some explosives there has nothing to do with the rules and regulations and backup plans.”

While a sailboat would not typically be a sound choice for most deep-sea diving operations, in the case of a clandestine military or paramilitary operation, Peter Andersson says it would be a brilliant cover. “When you see a sailboat, the last thing you think of is diving,” he said. “That is a perfect disguise. If you take all the ships and the vessels that you can figure out to take — like a freight boat, canal boat, or whatever — the sailboat is the best way to disguise the diving operation because nobody would think that’s what you’re doing.” He said that if you had three or four strong individuals onboard, they could use ropes and other tools to retrieve the divers and equipment.

The divers, he said, would not have to be tethered to the boat. They could be dropped in the water and later use a marker buoy to identify themselves once they ascend. The boat could then cruise around in wait for the mission to be accomplished. Transporting the explosives to the bottom of the sea, even if they weighed hundreds of kilograms, he added, would be possible if the saboteurs used buoyancy bags. “And then you can work down there and even if you want to stay down there for one hour, it will only take like 3 hours to get to the surface in total,” he said.

Just because it would be possible to conduct such a dive operation from a sailboat does not mean that is what happened. Jens Greinert, a marine geologist who chairs the Deep Sea Monitoring Group at the GEOMAR Helmholtz Centre for Ocean Research in Kiel, Germany, said he believes it would have been easier for the saboteurs to use remotely piloted devices rather than human divers to plant the explosives. “Personally I think it was either a small submersible, which doesn’t have to be big, or it was something along the lines of a robot,” he said in an interview with our reporting partner ARD. “You don’t need a diver to put anything in the sediment. I would even say machines can do it better.”

A former German military diver, however, was skeptical a submersible or robotic device was used to plant the explosives. Noting that the Baltic Sea is heavily surveilled, he said that using such equipment capable of planting bombs would have drawn far more attention and potentially necessitated a much larger vessel than a sailboat. “Both are possible, but it would have been a very sophisticated and very expensive robotic,” he told our reporting parter Die Zeit. “If it was a sailing yacht, it would have been complicated to deploy a robotic, because of the weight but also for the steering mechanism. You would need a calm sea and no wind.” He estimated that if humans planted the bombs, each dive would take between 30 minutes to two and a half hours depending on the equipment used and how much time was spent on the sea floor identifying the lines and planting the explosives.

When the Andromeda story first emerged in March, German officials cautioned that the ship could be a “false flag” to conceal the true identity of the saboteurs or that other ships may have been involved. The amount of evidence left on the boat and the trail of digital clues leading to Ukrainian individuals appeared to be either deliberate or the work of sloppy amateurs.

DRANSKE, GERMANY - MARCH 17: The kitchen area and table stand inside the Andromeda, a 50-foot Bavaria 50 Cruiser recreational sailing yacht, as the boat stands in dry dock on the headland of Bug on Ruegen Island on March 17, 2023 near Dranske, Germany. According to media reports, German investigators searched the boat recently and suspect a six-person crew used it to sail to the Baltic Sea and plant explosives that detonated on the Nord Stream pipeline in September of 2022, causing extensive damage. Investigators reportedly found traces of explosives on the table inside the yacht. While initial findings point to a possible Ukrainian connection to the sabotage operation, many questions remain open.  (Photo by Sean Gallup/Getty Images)

The kitchen area and table stand inside the Andromeda on March 17, 2023.

Photo: Sean Gallup/Getty Images

German investigators appear to be intensifying their probe of possible Polish connections to the attacks, something Warsaw has consistently denied. The Andromeda is known to have made at least one 12-hour stop at a port in Poland during its voyage in the Baltic, and the Wall Street Journal reported that the Andromeda suspects “used Poland as a logistical and financial hub.” The Polish government said that allegation was “completely false and is not supported by the evidence of the investigation.”

Along with Ukraine, the Polish government was the most vehement opponent of the Nord Stream pipeline. Poland has direct access to the sea and held its own exercises, code-named REKIN-22, in the Baltic in late September, just days before the pipelines were sabotaged. The day after the blasts, Poland cut the ribbon on a new pipeline that was established as a direct competitor to the Moscow-led initiative. The Wall Street Journal revealed that the Ukrainians who rented the Andromeda were Polish residents and used local bank accounts and paralegals for their business. “There is no evidence whatsoever that would indicate the involvement of Polish citizens in blowing up the Nord Stream pipeline,” Polish investigators said in a carefully worded statement June 21.

“Russia, the United States, and any number of other state or independent actors have the infrastructure and ability to have carried this off at a reasonable cost,” said a former U.S. Navy underwater demolition specialist who reviewed Erik Andersson’s footage and other images. He spoke on the condition of anonymity because he now works in the private sector and is not authorized to speak to the media. “It doesn’t have to necessarily be a James Bond-esque operation.”

Erik Andersson, at his home in Gothenburg, Sweden, explains why he decided to launch his own investigation into the Nord Stream pipeline bombings and the route he took on his expedition to the Baltic Sea.
Credit: Video footage courtesy of our reporting partner ARD.

Seismic Readings

Andersson’s data suggests that the seismic readings registered after the explosions were not caused exclusively from the detonation of the bombs, but were also the result of the sudden and immensely powerful release of the pressurized gas from inside the pipelines. Andersson reached that conclusion after he and his son, a computational engineer who works on seismic surveys in the oil industry, ran a series of advanced mathematical equations. First, they solved Euler’s equations in the geometry of the pipelines, which created a basis for them to make calculations about what happened inside the lines after they were punctured by bombs. This data allowed them to utilize seismic air gun simulation software developed at Stanford University to understand the dynamics of the massive gas bubbles caused by the puncturing of the lines. They also ran the rocket equation to calculate the propulsive force of the gas. “The signature of the gas explosion is much bigger than the signature from the bombs,” Andersson said.

If their calculations are correct, various speculations that the explosions would have required 500-900 kilograms of explosives may be erroneous. The New York Times cited a European lawmaker briefed by his country’s foreign intelligence service late last year as saying more than 1,000 pounds, or 453 kg, of “military grade” explosives were used in the operation. “I am saying with high confidence that I don’t think the bombs were that big,” Andersson said. “The size of the bomb cannot be determined by the seismic data currently available.”

Andersson used side scan sonar imaging to create underwater maps depicting the condition of all four Nord Stream pipeline strands in May 2023. The images were captured by Captain Patrik Juhlin of the Baltic Explorer. The first explosion of the Nord Stream sabotage occurred on a section of Line A of the Nord Stream 2 pipeline off the coast of the Danish island of Bornholm at 2:03 am on September 26, 2022. The puncturing of the pipeline caused a massive release of gas, resulting in high thrusts that severed sections of the pipeline and left large craters on the seabed.

Graphic: The Intercept / Sonar images by Patrik Juhlin of the Baltic Explorer and Erik Andersson

But Andersson is not just relying on calculating seismic and hydroacoustic levels to determine the size or placement of the bombs. His footage of a blast hole and other detonation sites suggest that the sabotage could have been accomplished with a smaller quantity of explosives: 50 kg or less for each line. “Fifty kilograms placed at intersections with concrete supports would probably do the trick,” said the former Navy demolition specialist who reviewed the footage. “At given pipeline pressures? Wow.” He and a German military explosive expert who also reviewed Andersson’s images agreed the bombs could potentially have been as small as 10 kg each depending on the specific type of explosives used.

Andersson’s video footage of the pipelines has convinced him that the saboteurs used slabs of explosives, rather than shaped charges, to puncture the lines. “It’s sloppily put there. It’s not professionally applied to surgically cut a hole in the pipeline or anything like that. That’s not what we’re seeing. It was crudely dug in a little bit in the mud next to the pipeline,” he said. “I think it tells a story of a diver who was in a hurry, perhaps diving without the possibility of surface decompression and thus only having 10-15 minutes to spend on the bottom.”

The former German military diver, who reviewed Andersson’s footage, agreed with his assessment that slabs of explosives rather than shaped charges were likely used at the site of the second explosion on Line A of Nord Stream 2. “With a shaped charge, we would see markers, cuts, the impact of the charge,” he said. “We would recognize it clearly. We don’t see that here. Everything speaks to a slab charge.”

With the images and footage currently available to the public, it is difficult to determine the nature of all of the bombs and whether they were identical at each site. The former U.S. Navy specialist said he would not entirely rule out that the saboteurs used cutting or shaped charges at some point in the operation because of their ability to forcefully and quickly pierce through metal and concrete. “I don’t think ‘cutting charges’ are mandatory given hydraulic pressures at depth and placement of charges,” he said. “Deformation of the pipe at a welded junction to the point of failure doesn’t require a cutting charge, in my opinion. But cutting charges make sense and are within the realm of plausibility for sure.”

Andersson also believes that his footage indicates that only one bomb was intended for each line, not two as Hersh has at times suggested. “I gave up the theory of double bombs after the expedition,” Andersson said. “I think there were just four.” All of this in turn could make it more plausible that a small team of divers could have pulled off the operation and not necessarily one sponsored or deployed by a major nation state like the U.S. or Russia. This would not exonerate any particular suspect, but it does suggest a wider circle of actors, nation states, or private groups could have pulled it off. 

Andersson may also have solved one of the several sub-mysteries of the Nord Stream saga: Why were only three of the four pipelines attacked? Proponents of the theory that Moscow did the bombing have pointed to the fact that the line closest to Russian territory was not damaged. This, they say, may be evidence Russia wanted to preserve a line in order to swiftly resume gas delivery should political winds shift on support for Ukraine or if Germany had faced a fuel or heating crisis last winter, as many analysts had predicted. Hersh, meanwhile, claimed that the bomb planted on the line closest to Russia simply failed to detonate and that the U.S. military clandestinely removed the evidence. “We were there within a day or two and picked it up and took it away so nobody else could see what kind of evidence there might be with the weapons used,” Hersh said.

Andersson believes that the saboteurs accidentally placed a second bomb on a northern section of Line A of the Nord Stream 2 pipeline. That explosion did not result in the type of massive damage as the other three bombs because it had been depressurized following the initial blast 17 hours earlier. Line B of Nord Stream 2 was the only line to escape damage from the sabotage. Andersson believes the saboteurs experienced magnetic interference with their compasses when trying to place a bomb on Line B and accidentally rigged a second bomb to the A line, which was just 50 meters away.

Graphic: The Intercept / Sonar images by Patrik Juhlin of the Baltic Explorer and Erik Andersson

On June 20, Der Spiegel reported that German investigators believe the fourth line was actually rigged with a bomb, but that it was a much smaller device than the others. But an official from Nord Stream 2 AG, the company that owns the pipeline, said that line is functional and remains filled with gas, though the company intentionally reduced its pressure to half the level it functioned at prior to the blasts. “Our concern is to safeguard the integrity of the line and safeguard any risk to the environment, to understand how we could stop any further gas seepage from the lines,” said the official, who was not authorized to speak on the record.

On his expedition, Andersson filmed the aftermath of the destruction caused by the first bomb of the sabotage action, the one that blew up Line A of the Nord Stream 2 pipeline at 2:03 a.m. About 70 kilometers northeast of that blast site, Andersson shot video of a puncture wound he believes was caused by a second bomb on that line. This was the discovery he described as the “holy grail” of his mission. He was able to film it because the line had depressurized after the initial blast, so it did not break the pipeline apart, and the hole from the bomb remained intact. That hole is just 50 meters away from the other strand of the Nord Stream 2 pipeline, the one closest to Russia.

Andersson suspects that the saboteurs encountered magnetic anomalies on their compasses when they were under water causing them to accidentally place two bombs on Line A of Nord Stream 2. “I would have made the same mistake with my drone if the captain hadn’t told me to make small moves and always return to the starting point,” Andersson said. “The compass pointed in the exact opposite direction of what it should, and before [the captain] advised me to turn back, I was heading full speed towards the wrong pipe. They are only 50 meters apart in that location. Maybe the compass failure was because of stray electrical currents in the pipeline itself, and if that situation appeared when the perpetrators executed their mission their compasses would have led them to the wrong string. It is possible that they accidentally blew up the A-string of Nord Stream 2 twice.”

On May 24, 2023, Erik Andersson filmed a northern section of Line A of the Nord Stream 2 pipeline. Andersson believes this footage contains the only known images of primary damage from the sabotage bombings. He believes the saboteurs mistakenly placed a second bomb on this line instead of strapping one to Line B of Nord Stream 2. This site may offer clues as to the size, nature, and placement of the bombs. It may also explain why Line B was apparently not directly attacked.
Credit: Footage copyright Erik Andersson.

A group of journalists who filmed a documentary for the BBC and Sweden’s Expressen newspaper encountered a compass malfunction similar to the one Andersson experienced when they filmed over the site late last year, according to a source who participated in the expedition.

Poseidon’s Peter Andersson made clear he has no decisive theory on what happened but said he believes the erratic compass theory is technically plausible. “When you’re trying to put the bombs under the pipe, you need to dig a little bit with your hands. It’s not rock-solid clay or something, it’s more like silt. It’s very loose, but you need to dig a little bit. And when you do this, the visibility becomes totally zero. It’s like in a mud cloud,” he said. In this case, he said, the saboteurs would have needed to rely exclusively on the compass readings. If those were inverted, as was the case with Erik’s readings during his survey of the Nord Stream 2 lines, it is possible they mistakenly placed a bomb on the wrong line. “If you’re doing this, you’re a little bit stressed. You have no clue. It’s not like walking in the forest. You have no clue when you look up which direction you are going or which direction you came from, because you just have to look at the compass.”

The former German military diver agreed that such compass interference can happen, including near pipelines like the Nord Stream, but he said professional divers should know how to calibrate them and adjust to such anomalies.

Andreas Köhler is the senior research seismologist at Norwegian Seismic Array, a joint initiative established in 1968 between the U.S. and Norway to aid in the detection of earthquakes and nuclear explosions. He co-authored an academic research study with colleagues from Germany, Sweden, and Denmark on the Nord Stream blasts, which was presented at a geosciences conference in Vienna in April, and is working on another report with an international team. “We observe seismic signals from four explosions,” he said via email. “One in the early morning at NS2 Southeast of the island of Bornholm, and three in the afternoon Northeast of Bornholm. Our data suggests that at least two occurred at NS1, possibly all three.” Based on their modeling and available data, the scientists determined they could not rule out a second explosion on Line A of the Nord Stream 2 pipeline.

Andersson suspects that the possible second bomb on that line was not detected by seismologists because it occurred at the same time as much more massive explosions were taking place. Köhler, who was aware of Andersson’s expedition, declined to comment. “We can’t comment on any public or private investigation as we’re only focused on analyzing the seismological data, which is our expertise,” he said.

Another scientist involved with the international academic study did not want to be identified for fear of irritating their government. That person said that multiple nations operating in the Baltic, including the U.S., have access to a far greater array of data, including from seismic readings and hydrophones, than the scientists possess and would likely be able to determine exactly where bombs were detonated and how large they were. Those governments have not made any of that data available.

“It goes way back to at least the ’60s — where we had this program of planting underwater microphones, hydrophones, under the water, in various chokepoints around the world, under the different oceans and sea,” said James Bamford, an expert on U.S. surveillance systems who has written several books about the NSA and CIA. “So, working secretly with the Swedish government, the U.S. planted a lot of these undersea hydrophones under the Baltic Sea, and those are sitting down there. And what they do is they listen, and they’re listening constantly.”

Eric Dunham, a geophysics professor at Stanford University, has been studying the Nord Stream blasts and is trying to determine which underwater events were a result of bombs and which were caused by gas release or other aftereffects of the puncturing of the pipelines. There are many challenges involved in answering these questions — or to definitively test Andersson’s theories. “Larger explosives produce higher amplitude blast waves as well as create larger gas bubbles that oscillate more slowly. Both the blast wave and bubble oscillations create hydroacoustic and seismic waves,” Dunham said. “However, a likely complication in the case of the Nord Stream events is gas discharge from the pipes. If the gas discharge is large enough, it can alter the hydroacoustic and seismic waves that are generated.”

Andersson said the image painted by Hersh of a state of alarm among planners of the U.S. operation when one of the bombs did not explode was, to him, one of the most interesting parts of the story. “It seemed to have some account of what happened after the blast, that it was panic,” Andersson said. “Hersh referred to some panic when everything didn’t explode and that eventually they were racing with American ships to the site and picked up those bombs. And I’ve been really trying to get the actual time when this happened.” He spent months reviewing marine traffic data and satellite images for any evidence of a U.S. ship in the area to conduct the sort of crime scene cleanup that Hersh reported. “If it turns out that there actually were no unexploded bombs, then of course this is something that’s just a major hoax,” he said. When pressed, Andersson finally says, “I just don’t think it happened.”

Andersson’s current hypothesis is that a small team of divers placed a single bomb under both lines of the Nord Stream 1 pipeline and mistakenly placed two bombs on Line A of the Nord Stream 2 pipeline. For yet unexplainable reasons, the first bomb on that line exploded at 2:03 a.m. and then all the other bombs exploded 17 hours later.

Erik Andersson on the Swedish island of Lyr on June 17, 2023.

Photo: Agnes Andersson

Unresolved Questions

After Andersson’s expedition, reports emerged that German investigators had determined the type of explosives used in the operation, including octogen, which is insoluble in water and not difficult to obtain, particularly for a government. The Germans have reportedly matched samples taken from the blast site with the explosive traces left on the Andromeda. Andersson said he would like to verify those reports with his own evidence. “We took some sediment samples at the place where the bomb exploded on a depressurized pipeline,” he said. “It never hurts to double check.”

Two weeks after Andersson’s expedition, the Washington Post reported that the U.S. had intelligence three months before the attack that the Ukrainian military was planning an operation to sabotage the Nord Stream 1 pipeline using a small team of six divers. The paper asserted that European intelligence reports “made clear they were not rogue operatives. All those involved reported directly to Gen. Valerii Zaluzhnyi, Ukraine’s highest-ranking military officer, who was put in charge so that the nation’s president, Volodymyr Zelenskyy, wouldn’t know about the operation.” Die Zeit then reported that last summer the CIA directly warned Ukraine not to carry out such an attack.

Though it was not his aim, Andersson’s research directly challenges Hersh’s details, as well as the narrative preferred by analysts who believe Russia carried out the bombing. In short, his findings bolster the case that Ukraine — or private actors — could be responsible for the attack. As for his confirmation bias in favor of Hersh’s narrative, the expedition changed his mind. “It’s not the main hypothesis anymore in my mind. In my main story, they were fairly primitive divers going in with a big slab of explosives. They dug in next to the pipelines and they placed them. There were four separate dives, but there was simplified logistics. It could have been a small boat, and they made a big mistake, and they ended up putting one bomb on the wrong pipe. That’s the story that is in my mind.”

Andersson’s mission did not solve the mystery of the Nord Stream bombing — he never thought it would — but the data he collected does contribute to the public understanding of what occurred.

During his expedition, Andersson also discovered a single diver’s boot near the site of the string of the Nord Stream 2 pipeline that was bombed but did not explode. A freelance journalist who accompanied Andersson published an article speculating about the boot’s origins, but Andersson acknowledges that the boot could have belonged to any number of actors in the highly trafficked sea and may not be connected to the bombing. He admits that experts he consulted “didn’t make much of it.” But, he says, he cannot rule out that it was lost by one of the perpetrators and may contain forensic evidence linking it to the crime. “We never expected to find any traces of the perpetrators, but nevertheless we ran across a diver’s boot,” he said. “I have talked to Captain Patrik about retrieving the boot. We can do it, if someone pays for it. That would also be a good demonstration of what it means to dive at this site.” 

Greinert, the German marine geologist, cautioned that Andersson’s expedition took place eight months after the Nord Stream bombings. During that time, multiple governments have examined the crime scene and retrieved evidence. “What was looked at here in May is no longer the original,” he said. “You have to take that into account.” He added, “From what you see, you can only draw conclusions about what happened, not who. Unless someone has left his credit card there.”

Andersson said he is keeping an open mind about all possible culprits and is eager for his data to be reviewed by more experts who can fact-check his own calculations and hypotheses. “I want to put everything in open source for people to look at,” he says. “I think if a person is doing something, you should assume innocence until they’re proven guilty. But when big governments do things, they shouldn’t have that protection.” The Baltic Sea, he adds, is a heavily surveilled and trafficked body of water. It is populated by swarms of advanced underwater monitoring devices, with the skies above and the water below patrolled by multiple nations’ naval vessels and aircraft. Andersson refuses to accept that the U.S. and its allies do not know exactly what happened last September 26, and he questions the motives behind their secrecy. “I don’t think the nationality of the divers is the huge thing,” said Andersson. “The Hersh story and Andromeda story are very similar in terms of how the bombs were placed and the size of the bombs.”

While Andersson now doubts the veracity of many details in Hersh’s account of the Nord Stream bombings, he is not yet prepared to exonerate the Biden administration. “Even if Ukraine planned and executed the operation, I can’t stop thinking that the U.S. was in on it in a way that makes them responsible,” he said. “At a minimum, Ukraine must have been certain that the U.S. would celebrate a successful sabotage of Nord Stream. And that’s what happened. Antony Blinken said it was a ‘great opportunity’ and Victoria Nuland cheered that the pipes had been turned into scrap metal. So, if Ukraine did it, they did it for the team, and if they didn’t inform their team leader, the USA, about all details, it was because that’s what was expected of them.”

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