In my travels to our friends north of the US border, it is not uncommon to find “used vessels” in service that were never intended to be used that far north and for the record, this occurs in the USA northern states as well. The figure below is one that is used by many to establish the Minimum Design Metal Temperature (MDMT) of their vessels based on where in North America the vessel will be placed into service. There is quite a bit more to establish the MDMT of a vessel, but a basic test during an assessment/PHA/Audit is to find the MDMT on the nameplate or U1A form and then compare it to said map. If the MDMT does not correspond to the temperature based on your location, then there may be more that needs to be investigated. It is NOT as simple as a 1-to-1 comparison, but it is an excellent means to do a high-level evaluation.
MDMT and Atmospheric Temps
