The IMO Polar Code: what it requires of equipment on board

What the Polar Code is

The Polar Code is mandatory under SOLAS and MARPOL for ships operating in the polar waters defined by IMO. A ship gets a Polar Ship Certificate after a survey against the Code, and carries a Polar Water Operational Manual that describes how the ship and crew handle the conditions the certificate allows.

• Category A: ships designed for operation in polar waters in at least medium first-year ice
• Category B: ships designed for operation in thin first-year ice
• Category C: ships designed for open water or ice conditions less severe than A and B

Polar Service Temperature

The central number for equipment is the Polar Service Temperature (PST). For a ship intended to operate in low air temperature, the PST is set at least 10 °C below the lowest mean daily low temperature for the intended area and season. Systems and equipment required by the Code must be able to function at the PST, and materials exposed to it must be suitable for it. The PST is the temperature the heat tracing design, the thermostats and the lanterns have to be checked against.

The chapters that drive winterization

• Life-saving appliances: survival craft, launching arrangements and embarkation areas must be operable at the PST, which in practice means anti-icing of davits, release gear and the routes to them
• Machinery installations: machinery and systems must function at the PST, with attention to icing of intakes, freezing of piping and materials at low temperature
• Ship structure and stability: ice accretion is included in the stability calculations, which is why de-icing capacity on deck matters
• Safety of navigation and communication: navigation equipment must be protected against ice, and the ship must have the means to keep a clear view and keep the lights and antennas working

What it means for the equipment we deliver

The Polar Code does not prescribe products; it prescribes function at the PST and documentation of it. That is why the heat tracing package for a Polar Code vessel is designed per circuit against the PST, and delivered with the certificates and the data class needs:

• Raychem heating cables selected for the PST and the wind, with cut-to-length installation on davits, walkways and piping
• TEF 1058 heat trace junction boxes and terminations in stainless steel AISI 316L, tested well below the PST of most polar operations
• Thermostats and ThermoConnect controllers with alarm output, so the crew sees in the Polar Water Operational Manual which circuits are running
• Navigation lights and floodlights rated for the PST, and Compact navigation lights with heating base

Polar Code and class notations

The Polar Code sets the statutory minimum. Class notations such as DNV Winterized and the Polar class notations add detail and often go further. Most polar newbuildings carry both, and the winterization package is scoped against whichever is stricter for each area.

This article describes the structure of the Code. The binding text is the IMO Polar Code as amended, and the flag state and class interpret it for each vessel.