The Murmansk, a 210 m (689 ft) 13,000 tonne cruiser built for the Russian Navy in 1955 had been withdrawn from military service and was being towed to India to be scrapped. She broke away from her tug and ran aground in bad weather off the coast of Sørvær in Finnmark, northern Norway, in 1994.
Radioactive substances were identified on the wreck and the Norwegian Ministry of Fisheries decided that she had to be dismantled and recycled.
Six tenders were received by the Norwegian Coastal Administration for the €32 million (US$40.5 million) contract, with AF Decom winning out because its proposal was considered the safest according to health, environmental and technical feasibility.
AF Decom’s plan involved the construction of breakwaters and the establishment of a dry dock around the vessel to allow for its dismantling in situ. This plan offered a number of distinct advantages. It eliminated the risks and uncertainties that are involved with underwater operations and lifting; it minimised any health, safety and security issues; it minimised weather limitations during the demolition since the area is exposed to high winds and is renowned for rough seas; and it uses reputable and proven methods and principles. A significant advantage offered by the method was the ability it conveyed to control environmental issues that might arise during the ship’s removal – water dispersion routes are eliminated by the dry site and the dry dock itself serves as an effective barrier against the proliferation of waste and other materials that would inevitably fall from the wreck during its cutting up and removal.
Once the dry dock was completed, the water surrounding the ship was pumped out. Two Hitachi demolition specification excavators (a ZX800 and an EX1200-6) then began work to break the cruiser down using a variety of attachments, including 15 and 25 tonne Genesis shears. The machines then segregate the materials for recycling, including electrical components, asbestos, wood, chemicals, batteries, metals and material with low levels of radioactive contamination.
AF Decom’s goal is to achieve a recycling rate of 95% on the project. Material is sorted into containers on site, which are in turn transported by ship to appropriate waste and recycling facilities, eliminating the need for storage and additional transport to minimise the project’s impact on the local environment.
Waste is accounted for on a continuous basis during the project, with all outgoing containers being registered and recorded in project-specific records that are quality assured against waste and weight receipts from the recycling facilities in accordance to current Norwegian legislation. Complete waste records will be included in the project’s final report.
AF Decom manager Eirik Wraal said of the project: “By the end of July we had almost removed the whole of the top part of the ship had been removed and the ship cleaned and cleared of hazardous waste and explosives. The first few thousand tonnes of scrap had also been shipped for recycling.” Work on the Murmansk is expected to be concluded later this year.
The project was delayed by a massive storm that occurred during November 2010 that effectively destroyed the dry dock, thus necessitating its being rebuilt, a task that took almost a year to complete.
Removal and recycling of such constructions clearly require high standards where safety and handling of hazardous materials are concerned. “AF Group has, through several demanding decommissioning projects – onshore and offshore – built up core competence within this area,” said Pål Egil Rønn, CEO of AF Group.
Source: 14 November 2012http://www.khl.com/magazines/demolition-and-recycling-international/detail/item80583/The-Murmansk-a-ship-breaking-challenge-for-AF-Decom