Railroad Archives Online
- CollectionE0482 - 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
- 37 more...
- Item167-42A - Great Northern Railway Standard Signal Plans; Insulated Spread Rod, 1923
- Item167-46A - Great Northern Railway Standard Signal Plans; Signal, Semaphore Train Order - Location Number 1, Tools, 1917
- Item167-46B - Great Northern Railway Standard Signal Plans; Signal, Semaphore Train Order - Location Number 2, Tools, 1917
- Item167-46C - Great Northern Railway Standard Signal Plans; Tools, Signal, 1927
- Item167-48A - Great Northern Railway Standard Signal Plans; Train Order Signal - Location Number 1, 1917
- Item167-48B - Great Northern Railway Standard Signal Plans; Train Order Signal - Location Number 2, 1917
- Item167-53A - Great Northern Railway Standard Signal Plans; Bearing, Crank and Clamp for 6 Inch Pipe, 1917
- Item167-53B - Great Northern Railway Standard Signal Plans; Bearing, Crank and Clamp for Ground Signal Base, 1918
- Item167-54 - Great Northern Railway Standard Signal Plans; Clamp, Stay, for 5 Inch and 6 Inch Pipe, Ladders, Train Order Signal, 1917
- 82 more...