Scope and Content of Collection
Title: Union Pacific Company Elvas Interlocking Control Tower Records
Collection Number: MS 708
Union Pacific Railroad Company
Extent: 1 half box
California State Railroad Museum Library and Archives
Sacramento, California 95814
Abstract: These papers are from the Southern Pacific, later Union Pacific, Sacramento interlocking control tower at Elvas.
Language of Material: English
This collection is open for research at our off-site storage facility with one week's notice. Contact Library & Archives
staff to arrange for access.
Copyright has not been assigned to the California State Railroad Museum. All requests for permission to publish or quote from
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as the owner of the physical items and is not intended to include or imply permission of the copyright holder, which must
also be obtained by the reader.
Union Pacific Company Elvas Interlocking Control Tower Records. California State Railroad Museum Library and Archives
Interlocking towers were commonly used to control and sequence the movement of trains at crossings and junctions where the
tracks of two or more railroad routes crossed or diverged. Southern Pacific's Elvas Tower controlled operations at the junction
of the Donner and Valley routes in North Sacramento. Trains heading east from Sacramento could be routed south to Stockton
or east to Roseville and points beyond.
The Elvas Tower was built in 1910 near the intersection of C Street and Elvas Avenue in Sacramento (adjacent to Interstate
Business Route 80 and across the American River from CalExpo.) The structure was a two-story wood frame building equipped
with a General Railway Signal Company (GRS) Model 1 all-electric interlocking machine. The tower operator's cabin was on
the second floor with windows on all sides. The original GRS machine remained in service until the Tower's last day of
operation. When Union Pacific's Jerry Davis Yard in Roseville was modernized in 1999, Elvas Tower's control functions were
moved to Roseville. On November 1, 1999 at 10:07 a.m., Arthur L. Spackman shut down the Elvas Tower.
Key architectural elements from the second floor and some equipment were donated to the California State Railroad Museum.
Scope and Content of Collection
These papers from Southern Pacific, later Union Pacific, Sacramento interlocking control tower at Elvas include a crew notification
data report sent by the crew caller's office in Omaha to the Elvas Tower on its last day in operation (November 1, 1999).
The report includes the train number, where it originated, the route it took, the time a train was expected to pass the tower,
and crew information from the last day of operation.
Signal control dispatching used the Centralized Traffic Control System and freight car management used the Transportation
Control System. One file contains codes that allowed the Elvas Tower crew to access train movements, consists, routes, schedules
and other important information in these two systems.
The Elvas Tower crew recorded all passing trains and the time they passed the Tower. A record book contains entries for October
19 to November 1, 1999.
System Special Instructions (effective October 25, 1998) provides updated information for rulebooks and Superintendents’ bulletins.
Another file contains telephone lists and directories of Southern Pacific employees in dispatch, operating, and maintenance
of way positions.
Monthly time reports include Elvas Tower crew members and the number of hours they worked during the last few months of operation.
Employees included: Bob Greenfield, J. S. Hansen, R.L. Prince, C. J. Riley, Arthur.L. Spackman, C.J. Riley, and D. Rosen.
There are also track bulletins [Form C] which alert Tower employees of any irregular movements.
The Elvas Tower crew also kept schedules for the Amtrak passenger trains which regularly passed the Elvas Tower.
Miscellaneous documents include: a cover sheet from a fax by California Northern Railroad, a 1999 yearly calendar, and a page
of assignments and changes in car management.