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
- ItemCover - Great Northern Railway Standard Signal Plans; Cover, 1905-1962
- ItemIndex - Great Northern Railway Standard Signal Plans; Index, 1905-1962
- Item167-09 - Great Northern Railway Standard Signal Plans; Rod, Switch Box, 1913
- Item167-09A - Great Northern Railway Standard Signal Plans; Connections - Switch Box Connections, 1922
- Item167-10 - Great Northern Railway Standard Signal Plans; Switch Box Application, 1915
- Item167-11A - Great Northern Railway Standard Signal Plans; Trunking and Capping, 1917
- Item167-11C - Great Northern Railway Standard Signal Plans; Trunking - Groved, 1923
- Item167-12 - Great Northern Railway Standard Signal Plans; Insulation for Switch Rods, 1915
- Item167-13 - Great Northern Railway Standard Signal Plans; Chutes, Elevation, Plan for Signal Foundation, 1913
- 119 more...