Structural Requirements for Polar Class Ships
The hull areas of polar class ships are separated in four parts: Bow, Bow Intermediate, Midbody and Stern. The Bow Intermediate, Midbody and Stern
parts are further divided in the vertical direction into the Bottom, Lower and Ice belt areas (IACS Req. 2006/Rev.3 2016). The bow is designed to resist in ice loads. Ship structures that are not directly subjected to ice loads should be approved from the classification societies (IACS Req. 2006/Rev.3 2016).
Method for determining equivalent ice class
The process for considering A and B categories of ships can be the same for both new or existing ships. The approval for the construction should be undertaken from the state of Flag or by recognized organization acting on its behalf under the provisions of the Code for Recognized Organizations (IMO, Annex 10, 2014). Various classification societies have improved ways to comply with the IACS Polar Class. The scope of IACS Polar Class is to ensure that, machinery installations are capable of delivering the required functionality necessary for safe operation of ships (IMO, Annex 10, 2014). If the vessel doesn’t full comply with the requirements, then the risk increased and the insurance premium. Moreover, vessel that would approve for PC 5 requirements but in limited areas is only PC 7 could still be considered as a category A, PC 5 vessel (IMO, Annex 10, 2014). Additionally, in all below cases the ships that complying with the ice class categories should have Polar Ship Certificate (IMO, Annex 10, 2014).
Figure: INTERNATIONAL ASSOCIATION OF CLASSIFICATION SOCIETIES, Requirements concerning POLAR CLASS, IACS Req. 2006/Rev.3 2016
Generally, the ice class ships are structured from strength hull structural steels. The range of the structural steels varies 235 ; ReH; 390 N / mm^2 and Re?315 or 355 N / mm^2 according to the type of the ship and the thickness of the ice that it will be activated. (GERMANISHER LLOYD, 2016). Furthermore, aluminum alloys are suitable for seawater as specified in the GL Rules for Materials and they are used for the building of superstructures, deckhouses, hatchway covers. The conversion from steel to aluminum scantlings is to be carried out by using the material factor (GERMANISHER LLOYD, 2016).
In conclusion, the Shipping Routes will be very popular in the futures as the climate change melt the ice of North Pole. As mentioned before, vessels must have specific characteristics, materials and design for the ice conditions. All the above contain expensive and high standard ships, if we would like to build or buy them. Moreover, if we want to use the existing fleet and they are not ice class contractions we should do fleet conversion, with other words reconstruction of the existing fleet. The ship conversion is a very sophisticated, expensive and bureaucratic project according to my research. On the other hand, a new ice Polar fleet is very expensive and time-consuming project that involve risk as a business plan. Despite the above fact, it is my belief that using the Arctic Shipping Route safety risks overweight the cost risks. In long term period original ice class vessels will be more profitable than a conversion fleet that hide both safety and cost hazards. Finally, I would conclude that activating in high risk area both safety measures and cost estimates are never enough.