Railroad Archives Online
- CollectionE0483 - Great Northern Railway Historical Society Standard Signal Plans Collection
- Series003 - Great Northern Railway Company (U.S.)
- Subseries Level 1009 - Engineering Records
- Subseries Level 2008 - Physical plant drawing
- Subseries Level 3005 - Signals
- 122 more...
- Item167-151 - Great Northern Railway Standard Signal Plans; Pole Steps, 1956
- Item167-152 - Great Northern Railway Standard Signal Plans; End of Siding Signal Layout, 1953
- Item167-153 - Great Northern Railway Standard Signal Plans; Lightning Arrester Innstallation, 1932
- Item167-154 - Great Northern Railway Standard Signal Plans; Lightning Arrester Box, 1927
- Item167-155 - Great Northern Railway Standard Signal Plans; Relay Shipping Box, 1927
- Item167-156 - Great Northern Railway Standard Signal Plans; Signal, Arrangement of Light Type Heads, 1956