UR I
Polar Class
UR I1 Rev2 CLN
UR I1 Polar Class Descriptions and Application - Rev.2 Apr 2016
UR I2 Rev4 CLN
UR I2 Structural Requirements for Polar Class Ships - Rev.4 Dec 2019 Clean
UR I3 Rev1 Corr1 CLN
UR I3 Machinery Requirements for Polar Class Ships - Rev.1 Corr.1 Oct 2007