Pimore than 1.6 million tons of unexploded ordnance pollute the North Sea and the Baltic Sea. Remotely operated bottom crawlers and robots with “smart tweezers” are now cleaning up these toxic munitions.
A box-shaped robot crawls along the seabed off northern Germany, reaches into the murky waters with a metal claw and picks up its target: a rusty hand grenade thrown into the sea after World War II. Above him, another robot swims to the surface, scanning the bottom for more ammunition. More robotic tongs reach into the water from above, picking up bombs and mines from the sediment.
When will this happen?
One pilot program supported by the German government will deploy these and other technologies in a Baltic Sea bay this summer to test a rapid, industrial-scale process for cleaning spent munitions that pollute the North and Baltic Seas. The project is part of a wider €100 million (£84.6 million/$106.9 million) program by the German government to develop a way to safely remove and destroy munitions scattered across parts of the country. North and Baltic Sea – a toxic legacy estimated at 1.6 million tons of discarded explosives and weapons.
“The problem is that in all maritime areas where a war has occurred or is occurring, there is ammunition in the sea. And when they remain there for a long time, they can release carcinogens” and other toxic materials, says Jens Greinert, professor of deep-sea monitoring at Christian-Albrecht University in Kiel, Germany, who works at the Helmholtz Geomar Center for Ocean Research in Kiel and is one of the scientists supporting the project. This interactive map shows where discarded conventional or chemical munitions were found.
“These munitions rust and our research has shown that over time, they release more and more carcinogens (and other toxic substances), traces of this have been found in fish and shellfish,” says Greinert. “The longer we wait, the more they will rust and the concentration of harmful substances in the water will increase. So now is the time to think about what we are going to do with these things while the ammunition is still intact enough to be grabbed.”
Based on scientific discoveries about the rusted and leaking ammunition, Germany decided that It’s time to try to get them out of the sea in scale. “Our starting point was to ask ourselves: what do we need to do to achieve a healthy marine ecosystem?” says Heike Imhoff, a marine conservation specialist at the German Ministry of the Environment, who oversees the project. The long-term goal is to build an offshore platform where munitions can be destroyed in a firing chamber after being recovered from the sea in a robot-assisted process, she says.
Until now, people have tended to take a piecemeal approach to removing unexploded ordnance (UXO) from the sea. For example, developers of offshore wind farms systematically examine potential bomb or mine sites and then avoid or remove them. To keep human divers out of harm’s way, these tasks increasingly involve robots that swim, dive or crawl. Untracked vehicles are also used in scientific research for ecological monitoring. They include remotely operated vehicles (ROVs), which are swimming or diving vehicles operated remotely via a deep-sea cable attached to a ship, and deep-sea crawlers, remotely operated vehicles that roll along the seabed on crawlers and can be equipped with various types of sensors and cameras.
What’s new in the program?
What’s new about the German pilot program is that it combines a range of specially modified technologies, including ROVs and custom crawlers, and uses them not only to remove individual bombs, but also to quickly remove masses of mixed munitions from densely populated areas. These rubbish bins are the legacy of Germany’s disarmament. After World War II, Allied forces seized their conventional and chemical weapons and dumped entire shipments of grenades, bombs and other munitions into the sea.
“For the last 10, 20 years we have been cleaning munitions for construction purposes – for wind farms, cables, port expansion– and we always clean them in areas where there is not much to clean, because landfills tend to avoid these projects,” says Dieter Guldin, head of SeaTerra, one of the UXO research and cleanup companies participating in the pilot program. “No one has ever said before: ‘let’s clean the munitions for the good of the environment, let’s clean the munitions to clean the sea’. It’s a completely new approach.”
A key part of this new approach is “direct disposal sites and do it on an industrial scale, working 24 hours a day”, it says. “With our current methods, it would take another 150 years” to clean German waters of munitions, Guldin estimates. “The goal of this project is to develop methods that will help us clean the sea within about 30 years.”
![German robots scour the sea for World War II bombs 1](https://thegurumedia.com/wp-content/uploads/2024/06/xartis_pyromaxika.png)
The first phase of the project, in which SeaTerra and other specialized companies are involved, will address several of these submerged piles in the Bay of Lübeck in the Baltic Sea. This is a fraction of the 400 stacks in the bay, but the idea is that the project will generate insights into how to automate and speed up the process.
Most of the technologies are already being used in offshore projects, Guldin says, but have been adapted to the challenge of dealing with landfills, which he describes as a “wild mix” of bombs, mines, grenades, ammunition crates and debris.
How is collection done?
O tools include an ROV equipped with a camera to inspect the seabed from above. Guldin describes it moving over the bottom, filming munitions, which experts aboard a ship can see on a screen and identify.
![German robots scour the sea for World War II bombs 2 robot thalassa](https://thegurumedia.com/wp-content/uploads/2024/06/robot_thalassa.png)
SeaTerra will also use “smart calipers,” a series of differently shaped sensor-equipped grippers that are attached to a ship’s cranes, Guldin says. They reach into the water and grab the ammunition gently or firmly, depending on its condition – a collapsed box full of ammunition may, for example, need to be retrieved with a claw that can be closed in a basin, he explains.
A crawler will roll along the bottom of the crawlers and pick up items like small-caliber ammunition with its smaller claw, Guldin says. All grabbers are equipped with cameras, allowing onboard experts to view munitions on screens. Smart handles then place the munitions into underwater metal baskets, pre-sorting them into roughly one or two types per basket. The specialized ship will be manned in shifts and will operate 24 hours a day: “All they do is identify the munitions and place them in the baskets, day after day,” says Guldin.
Source: BBC