Crossing of the Texas and New Orleans Railway and the San Antonio & Aransas Pass Railway
In 1876, the Texas Transportation Co. built tracks along the north bank of Buffalo Bayou between Clinton (now known as Galena Park) and downtown Houston. A few years later, these tracks came under Southern Pacific (SP) ownership and were assigned to its Texas & New Orleans (T&NO) subsidiary as the Clinton Branch. They proved valuable in serving port industries, particularly once the Houston Ship Channel was built.
The San Antonio & Aransas Pass (SA&AP) Railway entered Houston in 1888 from the west, crossing south of the downtown area and constructing a station at Polk Street. To make a connection with the T&NO main line near Englewood Yard, the SA&AP built an extension to the north, bridging Buffalo Bayou and crossing T&NO's Clinton Branch on the north side. On December 4, 1902, Tower 5 was authorized by by the Railroad Commission of Texas (RCT) for operation at this crossing with a mechanical interlocker having 12 functions (four home signals, four distant signals and four derails). Initially, RCT listed Tower 5 as being in "East Houston" but this was subsequently changed to "East of Houston", a location designation that persisted through the final detailed interlocker list published by RCT in 1931.
RCT files indicate that Tower 5 was discontinued on July 11, 1925 and then reinstated on March 10, 1927, but this period of discontinuance was never reflected in RCT annual reports. Other T&NO interlocker documentation explains that Tower 5 was "placed out of service July 11, 1925 account taking over the SA&AP Ry." This is consistent with the original RCT policy that required numbered interlockers only where two different railroads crossed. Once the SA&AP had formally been brought under T&NO control, the numbered interlocker was, in theory, no longer required, although this does not imply that the interlocking function was no longer needed. The T&NO documentation says that Tower 5 was "replaced in service as cabin interlocker on March 10, 1927...". Presumably, this was the date of the actual reactivation of the interlocker as a cabin-type system which would have required RCT approval. This may have been motivated by the approval process for Tower 121 in San Antonio, a Southern Pacific yard tower, in 1925. Tower 121 was the first "stand alone" single-railroad yard tower to be incorporated into the RCT numbering system, setting a firm precedent that interlocker approval was required, at least in some cases, where only one railroad was involved.
The 1928 RCT Annual Report was the first to list Tower 5 as an 8-function "mechanical-cabin". Cabin interlockers were used where the traffic was insufficient to justify a manned tower, typically in cases where one line was more heavily used and the other lightly used. By lining the interlocker to permit continuous movement on the busier track, trains on that line did not have to stop. When a train approached on the lightly used line, the crew would stop and manually throw the interlocker signals to permit passage over the crossing, warning oncoming trains on the busier line that the crossing was occupied. After crossing, the signals could be re-lined by the train crew to permit trains on the busier line to resume normal operations.
Although Tower 5 became a cabin interlocker in 1927, it was a manned tower for many years prior. The 1924 Sanborn Fire Insurance map of Houston (below) shows a small, square two-story "office" structure standing alone at this railroad junction. Presumably this is Tower 5 for there would be no other reason for such a structure to be located near a railroad junction. RCT files state that Tower 5's interlocking functions were moved to Tower 139 in 1940.
Historic Map, Tower 5 Location
Above: The 1924 Sanborn map of Houston shows the T&NO line running east-west along Baron Drive, just north of Clinton
Drive, crossing the SA&AP line about 500 ft. east of the bridge over Ingram's Gully. Below: A magnification of the map
shows Tower 5 documented in the southwest quadrant of the crossing (lower right edge of the image) as a two-story "Off"
[office] structure. The doorway was located on the south side of the building, and the rectangular shape and the lack of an
externally-indicated staircase implies that the staircase was inside.
Site Photo, Tower 5 foundation (Jim King, December 2006)
Above: This crumbling concrete foundation was found at the northeast corner of the adjacent lot, precisely
where Tower 5 appears on the Sanborn map. It is not known whether the cabin interlocker that replaced
Tower 5 also used this foundation.
Track Chart, T&NO Clinton Branch (courtesy,
Above: This image extracted from a 1926 T&NO track chart of the Clinton Branch shows the T&NO
crossing the SA&AP west of Baer Jct., but also includes a closeup of this crossing in the upper left corner.
The Tower 5 location is indicated on the southwest corner of the diamond.
Additional Photos, Tower 5 Site (Jim King, December 2006) - click to
Communications poles line the former T&NO
right-of-way looking west toward downtown.
Tracks remain in place to the north. Westbound trains arrive
from the right edge of photo and curve north toward Englewood
Yard. The "S-curve" in the foreground appears to result from
increasing the radius of the connecting track from the east while
maintaining the original northbound grade. The condition and
use of this track is unknown.
Signals for the grade crossing of the tracks are visible
along the right-of-way to the east, leading to Baer Jct.
South of Clinton Drive, the SA&AP right-of-way is
now an unusual looking greenbelt heading toward