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
- 99 more...
- Item167-124 - Great Northern Railway Standard Signal Plans; Bridge Rail Lock (Special), 1921
- Item167-126 - Great Northern Railway Standard Signal Plans; Latch Lock Shackles, 1921
- Item167-127 - Great Northern Railway Standard Signal Plans; Adapter Electric Lamp, 1912
- Item167-128 - Great Northern Railway Standard Signal Plans; Circuit Controller, End Lock, 1922
- Item167-129 - Great Northern Railway Standard Signal Plans; Cable, Dead Ends and Hangers, 1962
- Item167-131 - Great Northern Railway Standard Signal Plans; Cover, Station Indicator, 1923
- Item167-132 - Great Northern Railway Standard Signal Plans; Indicator, Station, 1923
- Item167-133 - Great Northern Railway Standard Signal Plans; Base for 4 Inch Mast, 1923
- Item167-134A - Great Northern Railway Standard Signal Plans; Bonding, Wireing, for Switches and Crossovers, 1928
- 20 more...