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
- 110 more...
- Item167-139B - Great Northern Railway Standard Signal Plans; Bracket, Horn, 1925
- Item167-140 - Great Northern Railway Standard Signal Plans; Markers, Permissive and Stop Signal, 1929
- Item167-141A - Great Northern Railway Standard Signal Plans; Dragging Equipment Dector, 1947
- Item167-142 - Great Northern Railway Standard Signal Plans; Interlocking Relay Test, 1953
- Item167-143 - Great Northern Railway Standard Signal Plans; Motor Car Shunt, 1953
- Item167-144 - Great Northern Railway Standard Signal Plans; Fouling Turnout, 1946
- Item167-145 - Great Northern Railway Standard Signal Plans; Washer Plate, 1944
- Item167-146 - Great Northern Railway Standard Signal Plans; Signal Locations , 1957
- Item167-147 - Great Northern Railway Standard Signal Plans; Background Adams and Westlake Lamp, 1958
- 9 more...