RedTex Tower, later renamed Staley, was the tower on the riverbank in Oklahoma just north of the Red River bridge, about 3 miles north of Denison. Since it was not in Texas, this tower is not included in the list of Texas Interlocking Towers. RedTex controlled traffic coming off of the Frisco from Madill, and leaving the Katy main for its own track into Denison. It also controlled the junction of the line to Ray Yards where it separated from the passenger main into Denison. It was also the terminus of the distance-separated double track (MKT) into Durant.
To understand how this tower came to be, some MKT history is in order. When Katy outgrew its facilities in downtown Denison, it built a new freight classification yard on the west edge of town and called it Ray. (Alongside was the Katy-controlled W.J. Smith Wood Preserving Company, which was Katy's source of crossties, poles, bridge timbers, etc., until the Katy was merged into the Union Pacific and the "tie plant" as it was known locally died.)
In time, the Katy outgrew Ray, and in the early 'Twenties built a huge new multiple-yard, rider-hump freight terminal complete with a new, brick roundhouse with locomotive shop northwest of Denison, named it Ray, and abandoned old Ray. The main line that went by old Ray remained in place and became the passenger main to Fort Worth and Wichita Falls until it was abandoned by William N. Deramus III, President of the MKT from 1957 to 1962.
Just east of old Ray, Katy installed a turnout in the main, named it Dallas Junction, and built a new, slightly serpentine freight route to the east end of new Ray. This new route was used by freights going through downtown Denison to/from the Dallas Subdivision line and by transfer runs between new Ray and the Katy car shops and the interchanges with the Espee, the Frisco, the Kansas, Oklahoma & Gulf, the Texas & Pacific, and the Texas Electric Ry., downtown. A new freight line was built from the west end of new Ray to a connection with the old main line named Pottsboro Junction. This was used by freights going to/from Whitesboro and thence Wichita Falls or Fort Worth.
Rather than having all freight traffic to/from the north wind its way through Denison over numerous grade crossings, Katy built a new freight line--named the Warner Cut-off--from the south end of the Red River bridge to the east end of new Ray. The new tower at Redtex/Staley was part of the overall new Ray project. If I remember correctly (and I AM a little fuzzy on this); it seems as if all switches were straight hydraulic (moving rods) on the north side of the river; but were controlled by electric transmission across the bridge to a hydraulic "shed" on the south side of the bridge, where the "rods" once again took over. Some of those runs would have had to been 3/4 of a mile.
In the photo, that's the old Frisco (now BNSF) line to Tulsa curving off to the left. If you look at the photo very carefully, you can see another turnout in the distance. This was the south end of Katy's double track that extended to Stringtown, OK, site of a huge limestone quarry. The southward track came straight down the hill, but the northward track turned east for a bit, found a somewhat easier climb, bypassed the town of Colbert, OK, then swung back to parallel the southward track at a point between Colbert, OK and Calera, OK.
South of the bridge, you had--from east to west--bridge tenant Frisco's main line into Denison, Katy's original line into Denison (passenger main), and Katy's Warner Cut-off to new Ray on the northwest corner of Denison.
Notice the Nunn-type train order signal on the tower. This device gave rise to the expression, "red board," often misapplied to block signals, but that's another story, and this one has reached the tonnage rating.
There was a tower at Staley (nee Redtex) operated by the Katy. It controlled switches at both ends of the bridge that allowed Frisco access to it, the switch on the south side where the old Katy main to the Denison passenger station and the Warner cutoff split, the siding, "Excess," and the switch on the north side where the double track from Staley to Stringtown, OK, began. The northward track swung to the east before turning north on an easier grade, bypassing Colbert, OK. The interlocker was part mechanical rods and part electrically controlled. It late years, the tower was closed, and control transferred to a panel at the Ray yard office. I suspect that control now is done by the Choctaw Subdivision dispatcher. TheStaley/Redtex tower stood at the north end of the bridge on the east side of the track.