Panhandle & Santa Fe Yard and Junction Interlocker at Canyon
Canyon, named for its proximity to the spectacular Palo Duro Canyon, received rail service in 1899 when the newly chartered Pecos & Northern Texas (P&NT) built a line between Amarillo and Farwell. In 1901, the P&NT was acquired by the Atchison, Topeka and Santa Fe Railway, which used the P&NT charter to expand operations in the Texas panhandle. New construction included a line from Canyon to Plainview in 1907, continuing to Lubbock (and a branch from Plainview to Floydada) in 1910. The P&NT was subsequently leased by (and eventually merged into) Santa Fe's Panhandle & Santa Fe (P&SF) subsidiary.
The busy Amarillo-Farwell main line ran through the middle of the Canyon yard with siding tracks on both sides, and the tracks to Plainview intersected the main line on the west edge of the yard. The proximity of the yard, the junction and the busy main line, with increasing speed and traffic, was the likely motivation for Santa Fe to improve yard safety by installing an electronic interlocker in 1927. All of these lines were P&NT tracks, so Santa Fe assumed that a new interlocker at Canyon would not require approval of the Railroad Commission; no other railroad was involved. As the Commission became aware of Santa Fe's construction, they inquired as to when they could expect to see the interlocker plans. In a letter dated October 12, 1927, P&SF responded to the Railroad Commission stating
"...it was not our understanding that plans should be filed with the Commission when an interlocking plant was constructed merely for the purpose of handling trains in and out of a junction point and no other railroad involved."
The Commission responded that they had never interpreted their policy as having any restriction on their authority to approve all interlockers. The precedent had already been set for single-railroad yard-related interlocking plants to be approved by the Commission with the establishment of Tower 117 and Tower 121 in 1924 and 1925, respectively, but both of these were actual tower structures built to house the interlocker controls and operators. Since the work at Canyon did not include a tower structure (but did include a branch line junction), the Commission's response to Santa Fe established that their approval policy was enforced for all interlocking plants regardless of structures and other railroads. Shortly after the Commission's response, P&SF submitted the required documentation and their electric interlocker at Canyon was designated Tower 135, authorized for operations on December 9, 1927.
This was a significant event in the history of state-level railroad interlocker management. From this point on, all railroads were officially on notice that internal junction and yard interlockers would require Commission approval. Ultimately the policy was extended to require Commission approval of more sophisticated controls such as Centralized Traffic Control. This policy ended in the mid-1960s by which time technological advances in control systems had long surpassed the ability of the Commission to manage and approve them. The last interlocker to be numbered and approved was circa 1966.
Above: This satellite image of Canyon shows the double track main line crossing
east/west and curving to the north toward
on the east side of town. The line to Plainview departs the main line on the
west side of town heading south. The
yards were located east of this junction, ending approximately where the main
line first begins to angle to the
actual location of the Tower 135 controls has not been determined, but was
probably a depot or yard office. Below: A westbound freight passes under the signal tower next to
interlocker/equipment cabinets in Canyon at the junction for
the line to Lubbock, the former site of the Tower 135 interlocker. (Microsoft
Virtual Earth image)