the new icebreakers, referred to as project 21900m, represent a further development of the original project 21900 design. modifications to the original design include, among smaller general improvements, a slightly different diesel-electric power plant configuration and more efficient pulling-type propulsion units where the propeller is facing forward. while project 21900m vessels were still sometimes referred to as "16-megawatt icebreakers", their propulsion power was increased to 18 megawatts. externally, the most apparent difference is the helideck which has been moved to the foredeck and enlarged for the bigger mil mi-8 helicopter.