Ice class notations
The IACS Polar Class notations PC1 to PC7, the Finnish-Swedish ice classes, and what each requires of hull scantlings, machinery output and operating limits.
Ice class notations are the class characters that state what ice conditions a ship is built to operate in, and they come from two largely separate systems: the IACS Polar Class notations PC1 to PC7, applied through the IACS Unified Requirements for polar ships, and the Finnish-Swedish Ice Class Rules used for Baltic winter navigation and administered by the Finnish and Swedish maritime authorities.
The full article will set out both ladders and the consequences that attach to each rung: hull scantlings and the ice belt, propeller and shafting strength, minimum propulsion power, steering gear and appendage protection, and the machinery and system arrangements needed to keep a ship working at low ambient temperature. It will explain why the two systems are not interchangeable and why a Baltic ice class does not translate into a Polar Class.
The article will also connect the notation to the operational regime that sits above it: the Polar Code, the Polar Ship Certificate, the Polar Water Operational Manual and the operational assessment that determines where a given ship may go and in what conditions, together with the fuel and lubricant cold flow requirements that follow. It links to the Polar Code and marine gas oil .