Northern Pacific semaphore signal display at Chehalis, Washington, on April 8, 1988. This structure is in the 3rd subdivision of the Tacoma division. Photo by GJ Werkema. Other subject classes: Signal, Semaphore

Northern Pacific semaphores, Marshall, Washington, April 13, 1968.

Northern Pacific signal bridge at Martin, Washington, circa 1960. Signal bridge with three signal masts, mainline, east portal of Stampede Tunnel in snow. Photo by J.M. Fredrickson . Other Subject Classes: signal equipment, track, tunnel, mountains

Northern Pacific signal equipment, Union Station, Tacoma, Washington, December 11, 1967. Outside of station with workers hoisting crate with Centralized Traffic Control equipment to platform roof. Photo by J.M. Fredrickson . Other Subject Classes: signal equipment, station, railroad employee

Northern Pacific signal equipment, Union Station, Tacoma, Washington, December 11, 1967. Outside of station with workers hoisting crate with Centralized Traffic Control equipment to platform roof. Photo by J.M. Fredrickson . Other Subject Classes: signal equipment, station, railroad employee

Northern Pacific signal equipment, Union Station, Tacoma, Washington, December 11, 1967. Workers installing new Centralized Traffic Control panel in dispatchers office; A. T. Brumfield, far right. Photo by J.M. Fredrickson . Other Subject Classes: signal equipment, railroad employee, dispatchers office

Northern Pacific signal equipment, Union Station, Tacoma, Washington, December 11, 1967. Outside of station, workers use NP crane to hoist crate with Centralized Traffic Control equipment to platform roof. Photo by J.M. Fredrickson. Other Subject Classes: signal equipment, station, railroad employee, crane

Northern Pacific signal equipment, Union Station, Tacoma, Washington, December 11, 1967. Outside of station, workers hoist crate with Centralized Traffic Control equipment to platform roof. Photo by J.M. Fredrickson. Other Subject Classes: signal equipment, railroad employee, station

Northern Pacific signal equipment, Union Station, Tacoma, Washington, December 11, 1967. Railroad employees installing new Centralized Traffic Control panel in dispatchers office; from left Jim R. Gibson, C. G. Stillman, A. T. Brumfield, unknown. Photo by J.M. Fredrickson . Other Subject Classes: signal equipment, railroad employee, dispatchers office

Northern Pacific signal equipment, Union Station, Tacoma, Washington, December 11, 1967. Outside of station with workers using NP crane to hoist crate with Centralized Traffic Control equipment to platform roof. Photo by J.M. Fredrickson . Other Subject Classes: signal equipment, station, railroad employee, crane