Dutch expertise raises Kursk

The nuclear-powered submarine Kursk sank in the Barents Sea at a depth of 108m on August 12, 2000 with the loss of 118 lives. President Putin of Russia promised to have the submarine salvaged so that the bodies of the drowned crew could be returned to their families. The salvors have just completed the tricky task of lifting the submarine from the seabed. Initial salvage discussions involved a consortium of salvor Smit, heavy lifter Heerema and underwater specialist Halliburton. These initial talks collapsed though, in May 2001, because the financing of the undertaking was incomplete. There was also a belief within the consortium that it was too late to begin the task of lifting the submarine if the job was to be completed this summer. At about the same time Frans Van Seumeren of Van Seumeren of Schiedam stepped in with a bid to do the job. This surprised many because Van Seumeren, although a specialist in heavy lifts on land, had hardly any experience with shipping and certainly none with salvage jobs at sea. Although Van Seumeren had bought Mammoet Transport from Nedlloyd in July 2000, it had hived off Mammoet?s interest in Mammoet Shipping to majority shareholder Spliethoff (which renamed the company BigLift). In spite of this, Van Seumeren teamed up with Smit to negotiate a successful deal with the Russian government. Smit could use such a job, its profitably having nosedived last year due to poor salvage results and higher interest charges, connected with its investments in port towage (increased shareholding in the Belgian Unie van Redding- en Sleepdiensten and the take over of Rivtow Marine in Canada). The f160 million ($66.3 million) deal struck with the Russians involved interim payments after the successful completion of each stage of the salvage, thus lessening the risk of failure. Mammoet, as main contractor, and Smit proposed cutting 26 holes in the submarine?s hull into which it could insert plugs onto which lifting cables could be attached. Before lifting could commence, however, the severely damaged bow section had to be cut off. Smit?s 24,000t pontoon Giant 4 would be used for the lifting operation, whereafter the pontoon would be towed, hopefully with the Kursk safely suspended below it, to Murmansk. Thereafter the Russian navy could take over the vessel by placing two pontoons on both sides to reduce the draft before entering a navy drydock. The contractors worked to a tight schedule, with the operation scheduled for completion in mid-September. In early July, Russian divers and divers of Norway?s DSND Subsea, contracted by Mammoet Transport, began the initial job of clearing the site and cutting the 26 holes in the hull with a high-pressure waterjet cutting tool. Their work, from the diving support vessel Mayo, was frequently delayed by bad weather but was completed nearly on schedule. Other vessels were on the site to guard the area and to monitor possible radiation leaks from the Kursk?s nuclear reactors. In late August they began removing the damaged, 20m long forward section ? using a remotely operated chain saw. Cylindrical drums covered with a very strong abrasive are attached to the chain on which a force between 300 and 500t can be applied. The system is patented by Smit. The cutting operation was required because it was feared that the bow would break off during the lifting operation, which would have a serious impact on the stability of the lift. After a successful start, delays were again experienced, but only partly on account of the weather, which remained favourable most of the time. The cutting saw broke halfway and later on got entangled in a pile of anchor chain when it was nearing the bottom of the submarine. The cutting itself was done without diver assistance, because torpedoes inside the bow section might explode during this operation. On August 28, Giant 4 left Amsterdam where repair yard Shipdock had made the pontoon ready for the job. The yard fitted leading pipes for the lifting wires through the hull of the pontoon, constructed a recess for the submarine?s conning tower and installed the foundations for the lifting gear. Van Seumeren?s hydraulics specialist Leo van Oostrum would oversee the raising of the wreck. After removal of the bow section, which will probably be salvaged next year by the Russian navy, a start could be made with the insertion of the plugs. This work met with delays due to obstructions, such as cables and ribs, inside the hull. Time was running out and the original date of September 15 for completion of the salvage passed. After that date, weather conditions could deteriorate rapidly. Fears were still expressed whether the bow had indeed been cut off entirely and whether the Kursk could be extracted from the mud in which it was partly submerged. Bad weather, with 6m high waves, prevented Giant 4 from starting the job. On September 28, a period of five days of good conditions (with wave height below Giant 4?s safe working limit of 3m) was forecast. Salvors began attach the cables to the plugs. Unfortunately, after only three of the 26 cables had been attached, bad weather again interrupted the operation. This relented though, enabling the operation to resume in early October. After all 26 cables had been attached, the lifting could start. As Giant 4 began its lift, two tugs pulled a cable along under the submarine to reduce the mud?s resistance. On Monday October 8, the wreck had been hoisted to within a few meters of the bottom of Giant 4. Two tugs then commenced towing the pontoon to Murmansk at slow speed. Once the Kursk was safely tied up to the pontoon?s bottom, speed could be increased for a mid week arrival at Murmansk. On arrival in Murmansk, it was necessary to lift Giant 4, with Kursk suspended below it, high enough to float it into the dry dock. This was achieved by two purpose-built sub-pontoons, called Mar and Gon. These were positioned under the port and starboard side of Giant 4. The next step was to pump out the ballast from the pontoons in order to raise the Giant 4/Kursk combination. At the time of going to press, modifications were underway to the sub-pontoons stability towers. Completion of this task will mean mission successfully completed.