www.txrrhistory.com - Tower 70 - Dobbin

A Crossing of the Trinity & Brazos Valley Railroad and the Gulf, Colorado & Santa Fe Railway

The Central & Montgomery (C&M) Railway was chartered in late 1877 by Montgomery interests to build a 25-mile rail line from Montgomery to Navasota, where a connection to the Houston & Texas Central Railway could be made. While all small towns desired to gain rail service during this era, it is likely that the impetus for this particular line was Montgomery's need to compete with Conroe, which had obtained  rail service in 1870. [It didn't work -- Montgomery lost the county seat of Montgomery County to Conroe in 1889.] The line between Montgomery and Navasota was completed in 1878, and in 1882, it was sold to the Gulf, Colorado and Santa Fe (GC&SF) Railway which wanted to build a line east from its main line at Somerville to the lumber mills of East Texas. The C&M line fit well with Santa Fe's projected route, and, despite some legal issues related to the sale, the C&M tracks were extended west from Navasota to GC&SF's main line at Somerville in 1883 and east to Conroe in 1885. The line remains in operation today by GC&SF's eventual successor, Burlington Northern Santa Fe (BNSF).

The Trinity & Brazos Valley (T&BV) Railroad was chartered in 1902 for construction of a line between Hillsboro and Mexia, but by 1905, it had become acquired by the Colorado & Southern Railroad under the control of B. F. Yoakum. Yoakum was also the CEO of both the Rock Island and the St. Louis San Francisco ("Frisco") railroads, and he used the T&BV charter to build from Mexia to Teague, and from Teague south to Houston and north to Waxahachie, where trackage rights to Dallas were obtained from the Katy on their Hillsboro line. This created a direct route between Dallas and Houston via Teague for the benefit of Yoakum's other railroads, including the Gulf Coast Lines. The north/south T&BV crossed the east/west Santa Fe line at a small community known as Bobbin. The name was changed to Dobbin in 1909, perhaps to avoid confusion with Bobville, a small town on the Santa Fe line about a mile from the crossing. The T&BV line was unprofitable, causing the railroad to enter receivership in 1914. Receivership ended in 1930 under the newly organized Burlington-Rock Island (B-RI) Railroad; its successor, BNSF, operates the line today.

To control the T&BV/Santa Fe crossing, Tower 70 was commissioned as a 12-function mechanical interlocker on April 25, 1907. The 1907 Annual Report of the Railroad Commission of Texas (RCT) lists the location as Bobbin. Despite the 1909 name change to Dobbin, the Bobbin name persists in the RCT reports until 1924. Tower 70 was likely a manned structure, but its fate is unknown and no photographs of it have been located.

Tower 70 Site Photos, courtesy of Tom Kline

This view north across the diamond was taken July 1, 1995. The former Santa Fe line crosses east/west (right-to-left) and the former B-RI line goes north/south
(top-to-bottom). The lines cross at an acute angle -- see satellite image at bottom of this page -- so the interlocker cabinet is actually due west of the diamond.
Note the manual interlocker control stand adjacent to the cabin, and the "70" on the side of the cabin.

In the late evening of March 4, 2001 we see BNSF conductor Charlie Holson opening the control box marked
'ATSF' at the former GC&SF/B-RI interlocker at Dobbin, TX. Charlie has walked down from his train seen
stopped in the distance at the absolute signal which is traveling east on the former AT&SF Conroe Sub between
Somerville and Silsbee. Charlie is pushing a button in the box which will check the track circuits for traffic on
the BNSF Houston Sub running behind him. If the interlocker finds the Houston Sub clear his engineer will get
a green signal to proceed through the crossing. The Houston Sub is the former B-RI mainline which runs between
Teague and Houston and their trains do not need to stop at this interlocker. If they do receive a stop indication
their crews follow the same procedure by pushing buttons in the adjacent box marked 'BN'.

While the interlocker is going through it's timing procedure a southbound BNSF train arrives in the distance
as Charlie gets a permissive white light on the control panel in the box. Even though the southbound on the
Houston Sub normally has the right of way, since it arrived after Charlie asked for permission, it will have to
wait since manual operations dictate first come-first served.

As the last car of the eastbound clears the diamond we see the southbound on the former B-RI is sitting stopped at
the absolute signal. In a few moments, they will get a clear signal to proceed through the plant and on into Houston.

Tower 70 Satellite/Location Map

A large inverted U in the lower part of this image shows a connection built by BNSF
to allow northbound trains on the former B-RI to go west on the former Santa Fe,
and eastbound trains on the Santa Fe to go south on the B-RI. The crossing diamond
is just above and right of the center of the photo, with the two lines forming a large
X pattern. The former B-RI runs southeast/northwest and the former Santa Fe runs


Last Revised: 12/6/2009 JGK - Contact the Texas Interlocking Towers Page.