A Crossing of the Galveston, Harrisburg & San Antonio; Galveston, Houston & Henderson; and Gulf, Colorado & Santa Fe railroads
Galveston was the major port for Texas and the southwest U.S. until well after the Houston Ship Channel was completed as a deep water port in 1919. It is not surprising that railroads crisscrossed the island to provide land connections for ocean freight. One major Texas railroad, the Gulf, Colorado & Santa Fe (GC&SF) Railway, was founded in Galveston, while two other major roads, the Galveston, Harrisburg & San Antonio (GH&SA) and the Galveston, Houston & Henderson (GH&H), had "Galveston" in their names; all three had roundhouses there. Via the Galveston Island Causeway, these three railroads accessed Galveston and its labyrinth of rail spurs to the docks and wharves. To help manage access to these rails, Tower 38 was established in Galveston on May 16, 1904 with a 66-function electrical interlocking machine built by Taylor Signal Co. incorporating 44 active control levers. The Railroad Commission of Texas (RCT) Annual Report for 1903 lists the location as "Galveston, 'Z' tracks" among a listing of interlockers authorized and under construction. The term "Z track" referred to a track that crossed the major rail lines in Galveston diagonally near 49th Street.
Galveston "Z Track"
Above: The "Z track" is the diagonal rail line running from lower-left to upper-right across the center of this image extracted from the 1912 index sheet of the Sanborn Fire Insurance map of Galveston. Tower 38 was located near the intersection of Market St. (Ave. D) and 49th St. Because this Sanborn map series was drawn so that most streets would appear horizontal or vertical, "up" is actually east-northeast (see compass image), and the Z track heading is east-southeast (left to right). A detailed Sanborn map (below) shows the precise location and orientation of Tower 38.
Above: "Interlocking Tower" (Tower 38) appears along the lower left edge of this image taken from the 1950 update to the original 1912 Sanborn maps. Again, "up" is east-northeast. The "2" in the tower rectangle indicates a two-story structure, and the dot indicates a door located along the short side of the tower facing the intersection of 49th St. and Avenue D ("impassable"). The map depicts the tower situated with a long side parallel to and southwest of the Z track, and north of the adjacent GH&H tracks on Ave. D. In the photo above, the main tracks are to the left of the tower, precisely the opposite of this map. This implies that the photographer was looking "down" the map, i.e. facing west-southwest, with the GH&H tracks extending to the horizon and the Z track crossing in front of the tower. The photographer is positioned above the side track that connects a "westbound" (outbound) movement from the GH&H to a "northwest" heading on the Z track. In the photo, where this connecting track nears the point where it will begin to curve to the right toward the Z track, a short crossover track to the left is visible that would permit a movement onto the GH&H outbound main track. This matches the track alignment shown in the above map. Note that the door represented by the dot on the short side of the tower is visible in the photo.
The above scan of a 1956 aerial photo shows the 51st St. overpass under construction. Tower 38 is to the left of center with the Z track crossing in front of it and the GH&H main lines behind it. The Z track continues into the foreground and connects to the Southern Pacific (SP, ex-GH&SA) tracks near the SP yard office (the two-story office building near the overpass). [photo courtesy Don Harper and the Galveston Railroad Museum].
Additional Photos from Don Harper, November 2006 (click to enlarge)
Don's comments: "Looking east, ground level, the inbound UP (ex-GH&H) lead is to the right and the outbound lead is in the middle. At far left is the lead to the Z track connecting the former SP (GH&SA) yard. The crossover from the Z track to the outbound UP lead can be seen. This is the same crossover that is seen in the 1921 photo (top of page)."
Don's comments: "Looking northwest, ground level, the UP inbound lead is to the left, the outbound lead is in the middle, and the Z track curves away to the right. In the background are the 51st Street overpass running left to right, and the elevated portion of Harborside Drive. Tower 38 was located very close to the power pole in the middle of the photo."
Don's comments: "Looking southeast from the Harborside Drive overpass, the Z track curves away from the UP leads heading toward the former SP yard. Tower 38 stood close to the power pole (upper center of photo surrounded by a clump of vegetation."
Don's comments: "Looking east from the 51st Street overpass, the UP (ex-GH&H) leads run straight from the UP yard toward the causeway bridge. The Z track can be seen curving off to the left toward the former SP yard. Tower 38 stood near the shorter power pole (surrounded by vegetation). The switch diverging from the inbound lead toward the right serves cotton warehouses. At one time (see the 1921 photo at top of page), a track diverged from the Z track, crossed both GH&H mains, and continued to the warehouses - the switch in this photo was not present in 1921. The ROW for this former track can be seen in the satellite image below. The ties from this track are still in place on the south side of the UP leads."
The Sanborn maps depict well-defined streets from the Galveston master plan, but some were never more than dirt tracks, many of which were never actually opened as streets. Thus, Ave. B (GH&SA), Ave. C (GC&SF) and Ave. D (GH&H) appear to have been used only as railroad rights-of-way in this area, and 49th St. no longer exists near the Tower 38 site (if it ever did). The elevated street junction is Harborside Drive and the Pelican Island Causeway (51st St.). Although the Z track crossing of the GH&H main is abandoned, the remainder appears to be in use. According to T&NO historian David Bernstein, the Tower 38 interlocker was replaced by two automatic interlockers in 1960. Interlocker 38A controlled the Z track crossing of the Santa Fe tracks and was retired in 1969. Interlocker 38B controlled the Z track/GH&H crossing and was retired in 1983. Don Harper reports that the mysterious faint line that tracks the apparent route of 49th St. (particularly noticeable crossing the lagoon at the 'F' in "GC&SF Main Tracks") is a pipeline!