Polar Service Temperature (PST)

Polar Service Temperature (PST) is the design temperature a polar-class or winterized ship is built to operate in, set by the IMO Polar Code at the mean daily low temperature for the intended area and season, minus 10 degrees Celsius. The PST drives material grades for exposed steel (low-temperature notch-toughness selection), the design of deck machinery, winterization of systems, and the suitability of survival craft and personal protective equipment. It appears on the Polar Ship Certificate alongside the assigned Polar Class. Steel and equipment must remain serviceable down to the stated PST.