Classic AT&SF Signaling
The 2nd District
History of Double Track and Signals on the 2nd District
Glossary
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This year will mark the end of classic D-251, left-handed signaling on the AT&SF. The once ubiquitous black cantilevers and signal bridges supporting H-2 searchlights and R2 color lights, all continuously lit, between Winslow and Gallup, New Mexico will fall in favor of field-side RACOs, as the final CTC push marches across Arizona to New Mexico. Once upon a time, D-251 left-handed stretched from Pineveta, Arizona to Belen, New Mexico, over 399 miles. Line relocations and CTC over the last 40 years has left only the Winslow to Defiance, New Mexico (west of Gallup) as the remaining stretch.
Why Left-handed Running?
One always associates left-handed running in the States with that of the C&NW's double-track mainline between Chicago and Council Bluffs, Iowa. Various explanations for this non-standard practice have ranged from initial ownership by the English, who naturally favored the left, to the station placement along the commute district. For whatever the reason, the C&NW was fortunate in that they installed cab signalling (1927-1928) on the entire routine, alleviating the need for wayside signaling. The result being they were not forced to erect signal bridges or cantilvers to satisfy the then standing ICC rule of no field-side signaling; hence it didn't cost them anymore to run on either the left or the right. The Santa Fe, on the other hand, preferred right-handed running when possible, but were forced to the left from time to time due to topology.
Nearly 400 Miles of Left-handed D-251
When President Ripley began the ambitious double-tracking program between San Bernardino, California and Belen, New Mexico the two most urgent areas was Cajon Pass and Supai Hill in Arizona. Both lines featured tortuous 3% grades, and in both cases, the newer and more favorable lines where located to the "north" of the original. The newer grades became the uphill track (eastward), and the original mainline became the downhill track (westward). Though the lines were states apart, they had the same effect of forcing a pattern of left-handed running, where the only solution when it came time to complete the double tracking and signaling was to construct fly-overs, or go to the expense of signal bridges and cantilevers. On Cajon Pass, a fly-over was constructed 13 miles east of Summit at Frost, to return to right-hand running. In Arizona, a fly-over was constructed on the westside of Supai Hill 10 miles west of Ash Fork at Pineveta, but for some unknown reason, the AT&SF never built a fly-over east of Supai Summit to return traffic to the right. So from Pineveta, on to Williams, Flagstaff, Winslow, Gallup and Belen, the AT&SF ran to the left. And where the grades were not separated, the AT&SF was forced to place signal bridges or cantilevers every mile or so. That's a lot of steel.
The First Changes
The Santa Fe's double tracking project was finally complete when DT Junction and Joseph City, Arizona was linked in 1940. And all was fine until faced with mounting competion from the new Interstate system in the late 1950s, This forced the Santa Fe to eliminate one of the biggest bottlenecks on the system by building an entirely new line between Crookton and Williams. The line change eliminated forever the fly-over at Pineveta, which they decided not to replace. The problem was how do you now cross the traffic from the north main to the south main between Crookton and Williams? The answer was two-track CTC. This obviously factored into the decision to put CTC into an already expensive project, but intially the CTC covered only from Seligman to Maine. The dispather was limited to 7 crossovers for which to swap traffic. Eventually CTC was extended to Winslow in 1966, and for the most part, the swapping was then done at Winslow, where the dispatcher had the luxury of a 3 track mainline. Mandatory lefthanded D-251 had been reduced to 250 miles, from Winslow to Belen.
More CTC
Though the really bad and sustained grades where in western Arizona, the railroad across New Mexico and the Continental Divide could drag a train down with grades of 1%. In the late 70's when coal reserves in western New Mexico became available and a number of on-line coal spurs where built, the AT&SF decided it was time to invest in more CTC. Consequently, by 1984 the entire 1st District of the Albuquerque Division between Gallup and Belen had two main track CTC. The practice remained, however, to run left-handed out of Belen. This relieved the dispatcher from having to needlessly swap a train south to north, or north to south, from Belen to Gallup. The 3rd District (Winslow to Seligman) was always forced to make the crossover because the 4th District (Seligman to Needles) was D-251 righthand (until recently).
This left the 3rd District as the final holdout of left-handed D-251, a mere 150 miles. For a long time on the Albuquerque Division you had this typical scenario of a westward train from Belen: Leave Belen left-handed, and though options abound, must be left-hand by Defiance (west of Gallup). Defiance to Winslow left-hand D-251. Winslow most likely the swapping point, but somewhere between Winslow and Seligman, the train needed to be on the north track.
The End of Left-handed D-251
It probably wasn't so much the left-handed running that doomed the 2nd District as it was the D-251, where slower trains are forced to hand throw the switch at a siding and, since the loss of the caboose, either line behind or leave it to the following train to reline the switch. In any case, the delays were becoming intolerable on a transcontinental that continues to see more traffic, especially the premium Z trains. Add to this the fact that the signal department wants to get rid of all pole lines, and where the safety requirements for a signalman to climb a bridge or canilever is becoming more restrictive, and CTC seems like a worthy capital expenditure. For classic D-251, left-handed, continously lit siganls, its time has come. Once the last CTC is cut-over, probably at the end of the year, will the dispatchers continue to run trains left-handed, where some grade separation in New Mexico favors this approach, or will it be right-handed all the way?
You are invited to take a tour of the railroad of the 2nd District, the last of the classic AT&SF signaling.