Three of the diesel-electric icebreakers - the Kapitan Sorkin, Kapitan Nikolayev and Kapitan Dranitsyn - were constructed as shallow-draft models. The Kapitan Sorkin and Kapitan Nikolayev were subsequently remodeled, the former as a WAAS vessel and the latter with a conical bow.
As the foregoing discussion indicates, Russia's fleet of icebreakers is the world's strongest, in terms of both icebreaking capability and number of ships. Unfortunately, Russia has built no new icebreakers since the construction of the Yamal in 1993. Construction of the Arktika-class nuclear-powered icebreaker Ural began in 1985, but fifteen years later its completion is nowhere in sight (the vessel's name has been changed to Victory in World War II). Despite the lack of new ships, the three oldest icebreakers, the Arktika, Sibir and Yermak, are scheduled to be retired in 2000. The Arktika and Sibir are two of the five 75,000HP icebreakers, while the Yermak was at the heart of Russia's diesel-electric icebreakers. Given the turmoil in Russia's economic condition, no plans to construct successors to these craft are expected to materialize at all in the near future. The demand for the services of these ships in NSR applications is far less than the strategic demand during the Soviet era, and indeed demand for icebreaker support of commercial shipping is shrinking. Some of these vessels are now used to serve the Arctic tourism industry. Nonetheless the polar icebreakers form a critical component of the NSR system. Just as the existing icebreakers are coming to the end of their service lives or becoming over-aged, the maintenance and replacement of Russia's icebreakers is becoming increasingly difficult.
(3) Escort operations
The operation of commercial vessels in the NSR is conducted in one of two modes. The first is unescorted mode, or independent operation, in which the vessel navigates in ice-infested waters on its own. When severe ice conditions are expected to produce significant delay in navigation or may disable the ship, this mode is eschewed in favor of the second: escorted navigation, or ice escort. In this mode, a convoy is formed with an icebreaker whose icebreaking capability is stronger than the commercial ship's. Under ice escort, the icebreaker takes the lead, opening a path through the ice for the commercial vessel. The composition of the convoy is determined by the condition of the ice; the more severe the ice conditions, the fewer ships are escorted by a single icebreaker. Generally, if ice concentration is 5/10 or 6/10, one icebreaker may escort three of four commercial vessels; with concentration of 8/10, the number of escorted ships is dropped to one or two. Thanks to Russia's wealth of experience in NSR operations, the following points of convoy formation have been learned with respect to navigation in ice-covered waters (WP-108).
* When convoys are formed with ships of different icebreaking capabilities, the ship with the poorest capability follow immediately behind the icebreaker and the ship with the greatest capability brings up the rear.
* When multiple icebreakers support a single convoy, the icebreakers are positioned at the front and middle of the convoy. The middle icebreaker assists ships that become unable to operate.
