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
- 68 more...
- Item167-78 - Great Northern Railway Standard Signal Plans; Wall Cover Plate, for Train Order Signal, 1918
- Item167-80 - Great Northern Railway Standard Signal Plans; Forms for Signal Foundations, 1923
- Item167-80A - Great Northern Railway Standard Signal Plans; Forms for Signal Foundations, 1923
- Item167-80B - Great Northern Railway Standard Signal Plans; Foundation Concrete Signal and Cable Post, 1924
- Item167-80D - Great Northern Railway Standard Signal Plans; Foundation Concrete for Case, 1955
- Item167-80E - Great Northern Railway Standard Signal Plans; Foundation Concrete Dwarf Signal Type S. A., 1957
- Item167-80F - Great Northern Railway Standard Signal Plans; Foundation Concrete Dwarf Signal, 1953
- Item167-80G - Great Northern Railway Standard Signal Plans; Foundation Concrete Pier for Large Case, 1952
- Item167-80H - Great Northern Railway Standard Signal Plans; Foundation Concrete Instrument House, General Railway Signal Compan (GRS), 1957
- 51 more...