QUOTE: Originally posted by West Coast S THE ERA OF THE SPECIAL DUTY SERIES ARRIVES ON THE SOUTHERN PACIFIC; In 1952 EMD began production of a model that would come to signify the Southern pacific's answer for severe tonnage ratingsover sever grades and light trackage requirements, the SD7 packing 1700hp with the new twelve axle Flexcoil trucks and employing maxium ballast in the frame for enhanced traction. SP could have placed this order for forty eight units with Baldwin or Alco, as both builders had a history of heavy road switcher deliveries to the SP, in the end, SP chose EMD reliability over increased horsepower per unit. SP wanted no surprises out on the road. Deliveries continued until mid 1954 when the SD9 sucessor was announced. They arrived wearing the standard switcher paint for units of over 1500hp of black carbody,silver ends and Daylight orange Tiger stripes, the famous "Black Window" colors were still a few years away for the SD7's. Numbered 4301-4347 the SD7's were immediently assigned to the tough and grueling Shasta Division, were they not only replaced steam but F7's as well. The displaced F units migrated to the Donner crossing, until sufficient SD deliveries caused them to be homeless again. No longer would it be required to mu ten or more F units to avoid burning traction motors when half the number of SD's could handle the task. Beginning in 1954 and continuing until 1957, 148 of the improved 1750hp SD9's were deilvered, SP rostered the largest fleet of both versions, numbered 4401-4547 these units were delivered from the factory in the now standard Black widow. With these units SP could retire steam en mass. Some of the SD7's, wore orginal switcher derived colors to the introduction of Grey and scarlet in 1961, the 7-9's were still considered first line mainline power, however, by 1965 with the arrival of newer power, SP reclassified them as heavy switchers and per standard practice renumbered them into the 3800 series, indvidule model classfication was no longer a factor. , however two SD9's escaped the renumbering 4450/4451 were reclassified as passenger power and retained their steam boilers for use on the Lathrop connection of the Daylight, considered the best scrubbed units on the road they were nicknamed "Huff and Puff" in difference to their lack of speed, they later migrated to the commute pool and saw service on company trains as well until retirement in 1984 . The SD's reigned supreme on the North Western Pacifc, heavy lumber traffic, questionable track conditions and many grades required as many as six to get the job done and there they stayed until the Union Pacifc merger. The complete SD roster was included in the 1967-1973 GRIP rebuild program, SP had no intent to re-invent the wheel, but incorporate new technologies not available when built, the horsepower ratings was not changed, no chopped noses were applied, but improved traction motors/ wiring and filter/spark arrestors were installed and the rear hood stripped of all light packages and the number boards plated over. Despite being renumbered yet again back to the 4300/4500's and offically confined to yard/transfer service, SP dispatchers would find mainline assignments for them as the recovery began and SP was caught flat footed with not enough locomotives and increased business, on a rare occasion they could be observed in the lead position leaving much newer designs to the trailing postions well into the nineteen eighties. All divisions of the vast system rostered the SD series for helper duty, locals, branch at one time or another. The final use of the 7-9's occured under Union Pacifc ownership when the final four serviceable units were assigned to duty out of Bakersfield in helper duty, lack of sufficient available ni the valley power caused UP to dispatch them in a pure set for one final mainline assignment in 1997. Thus writing the final chapter a magical era harking back to very begining of dieselization on the SP and the history of a remarkable locomotive series.. Dave
QUOTE: 100 was built by American Car in 1917 as Alton Granite & St Louis 60. In 1926 the line was reorganized as the St Louis & Alton Ry and the car remained 60. In 1930 the IT took over the line and renumbered the car 100 in April 1931
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