Waterjet Deconstructs Retired Ship Hulls

WEDNESDAY, NOVEMBER 15, 2023


German-based ship recycling company Leviathan is reportedly utilizing a large robotic arm, armed with a waterjet powerful enough to slice through steel, to chop up the hulls of large ships that are no longer in use.

According to a report from BBC, these hulls yield easily to the power of a cutting jet in comparison to previous methods of dismantling ship hulls.

About the Process

According to the report, when large vessels retire from ferrying cargo like consumer goods, or oil, between continents, they sometimes end up in recycling yards on heavily polluted beaches across South Asia.

At these locations, workers reportedly use fossil fuel-powered torches to take the ships apart. Protective clothing for the workers is reportedly scarce, and injuries and death can often result from this type of work.

The report states that contaminants, including heavy metals, often get washed into the sea from these beaches. Workers and locals are often exposed to asbestos and other dangerous materials because of this.

Over the next 10 years, 15,000 ships will need to be recycled, over two times the volume of the past decade, estimated the Baltic and International Maritime Council (BIMCO).

Now, the report says that Leviathan is looking for ways of doing this work in a much cleaner and safer way. However, there are still reportedly no guarantees that the companies will be able to compete with the low-cost yards being used in South Asia.

Leviathan reportedly plans to use a team of robots to dismantle huge ships to recycle steel instead of the current method, which has been referred to as “dirty” and “exploitative.”

"You can have robots starting at the bow and the stern, and two points in the middle, and working towards each other," said Bryce Lawrence, operations director at German based firm Leviathan.

"Compared to traditional ship recycling, we're very, very low carbon," Lawrence added, noting how machinery at Leviathan's Stralsund facility on Germany's Baltic coast will be powered by electricity, not on-site fossil fuels.

Additionally, Lawrence stated that recovered steel will be transported to mills around Europe on electrified trains and that commercial operations are reportedly set to start in the coming months.

The report states that Leviathan’s prototype system is a combination of created technologies. The robot arms are the same kind used in car factories, and the waterjet is built by another German firm, ANT AG.

This device reportedly shoots a mixture of water and sand at high pressures, acting accurately enough to be used by bomb disposal experts while cutting the fuses out of bombs.

"Somebody has to approach the bomb, put the manipulating system on," said Till Weber, ANT AG's general manager, "then go as far away as possible." Weber added that the jet can be used from a distance of half a kilometer (0.3 miles). Weber added that this technology is currently in use in the ongoing war in Ukraine.

When it comes to ship cutting, the system reportedly needs less workers than previous methods of shipbreaking do. Lawrence argued that this could serve to complete the job much faster at some point in the future.

The report states that computer software being developed by Leviathan is expected to automatically plan how to chop up a vessel as efficiently as possible. However, the robot arms reportedly need to be correctly mounted on special rigs fixed to a dry dock, they cannot be simply placed on a beach.

Sefer Gunbeyaz at the University of Strathclyde has studied workers' exposure to toxic materials at shipbreaking facilities in the U.K. and Spain. Even in these countries, exposure was "worrying," specifically to lead and iron particles.

"It's a promising start," Gunbeyaz said of the waterjet-based system in Germany. However, he noted that contaminants in the water used for cutting up ships still need to be carefully managed.

Lawrence explained that the Stralsund facility would have a containment area made to capture jet water and toxic substances that are blasted off ships. Once decontaminated, this water can reportedly be reused for more cutting.

Further Research

Additionally, earlier this year, Elegant Exit Company in the Netherlands also stated it has the technology to dismantle ships responsibly when it began recycling the Wan Hai 165, a 160-meter-long container vessel.

The company reportedly utilizes gas-fueled cutters at its Bahrain facility, though states that it removes hazardous materials before processing ships into large pieces of steel of up to 25 tons for transportation.

"We de-Lego a ship," said a spokeswoman, adding that the idea is to properly disassemble each vessel, part by part. The firm has stated that it will evaluate waterjet, plasma and hydraulic mechanical cutters in the future.

Recycling ships has been a dirty business for too long, stated Ingvild Jenssen, founder and director of Shipbreaking Platform, a non-governmental organization monitoring the industry.

"What is even more shocking is that you have a whole shipping sector that is well aware of the problems," she added.

Some ship owners reportedly try sending ships from Europe to South Asian shipbreaking yards despite such exports being illegal. A BBC investigation in 2020 revealed that three oil rigs detained by the Scottish Environmental Protection Agency (SEPA) in 2018 had been earmarked for dismantling on a beach in India.

Two of the structures have since been broken up at a European-approved yard in Turkey.

"[The third rig, Ocean Princess] has not been dismantled and recovered yet as it was only exported to Turkey in May 2023," stated Colin Morrow, of SEPA.

Improved documentation of the hazardous materials contained in a vessel could reportedly help recyclers process it properly, suggested Jenssen.

Kuishuang Feng at the University of Maryland agreed, adding that ship owners could be charged a levy when buying a vessel, which would be redeemable if it is later recycled safely.

Both Feng and Jenssen state that current legislation, including the ratified Hong Kong Convention, does not work hard enough to make shipbreaking sustainable.

However, a spokeswoman for the International Maritime Organization retorted, saying that the convention could potentially reduce the environmental impacts of ship recycling.

Lawrence stated that Leviathan hopes to license its system to other shipbreaking yards, though he insists that he would only allow this in safe, controlled environments with the same capacity for capturing hazardous substances that is in place at Stralsund.

At the moment, the situation in many South Asian yards remains one of "constant exploitation," said Jenssen.

"You have workers that go to work—and they're not coming home."

More Water Jetting

In June of last year, Everett Ship Repair, LLC, in Washington announced that it had purchased two new ultra-high-pressure water blasting systems to expand its surface preparation services. The 40,000 psi UHP systems were delivered to the shipyard and put into production in March 2022. 

According to the release, the system allowed the facility to deploy up to four water blasters simultaneously in a wide variety of applications, including internal tank hydro blasting for cleaning and coatings removal. The UHP systems were capable of standard surface preparation and specialty applications.

The robotic system also reduced the need for manlifts and scaffolding to access and remove coatings from a ship’s hull and other structures. Additionally, the water blasting system minimized labor and reduced the risk of injury or fatigue of personnel.

According to ESR, because UHP water blasting was a more cost effective and environmentally friendly alternative to solid abrasive blasting materials, the equipment moved towards the shipyard’s goals and commitments to adopt sustainable techniques to protect the environment as a green shipyard.

In terms of environmental impact, water blasting produces no air pollution, creates significantly less waste disposal over solid grit blasting and reclaims water through a separation system to leave non-hazardous sludge behind for disposal. Water blasting also creates less noise compared to sandblasting and mechanical methods of coatings removal.

ESR reported that it would also use the UHP system outside the shipyard, in addition to offering surface prep services for removal of unwanted or contaminated surface materials. The shipyard also planned to perform pipe cleaning, tank cleaning and UHP surface preparation for marine and industrial customers.

   

Tagged categories: Asia Pacific; EMEA (Europe, Middle East and Africa); Health and safety; Latin America; Marine; Marine; North America; Program/Project Management; Research; Research and development; Safety; Ships and vessels; Surface preparation; Technology; Tools; Tools & Equipment; UHP waterjetting; Waterjetting; Z-Continents

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