View source for EMD SDP40F

{{Short description|Class of diesel passenger locomotives}}
{{distinguish|text=the [[EMD SDP40]]}}
{{good article}}
{{Use American English|date=July 2017}}
{{Use mdy dates|date=July 2017}}
{{Infobox locomotive
| name             = EMD SDP40F
| image            = File:AMTK 629 with 5 Emi gap Feb 1978xRP - Flickr - drewj1946.jpg
| alt              =
| caption          = EMD SDP40F {{Abbr|No.|Number}} 629 with the ''[[San Francisco Zephyr]]'' in 1978.
| powertype        = Diesel–electric
| designer         =
| builder          = [[General Motors Corporation|GM]] [[Electro-Motive Diesel|Electro-Motive Division]] (EMD)
| ordernumber      =
| serialnumber     =
| buildmodel       = SDP40F
| builddate        = June 1973 – August 1974
| totalproduction  = 150
| rebuilder        =
| rebuilddate      =
| numberrebuilt    =
| aarwheels        = C-C
| uicclass         =
| Britishclass     = <!-- e.g. [[Bo-Bo]] [[1Co+Co1]] -->
| driver           = <!-- e.g. 1st, 2nd  or 3rd coupled axle -->
| gauge            = {{track gauge|ussg }}
| trucks           = HT-C
| bogies           =
| leadingdiameter  =
| wheeldiameter    =
| trailingdiameter =
| minimumcurve     =
| wheelbase        =
|  engine total    =
|  leading         =
|  drivers         = <!-- USA terminology -->
|  coupled         = <!-- British terminology -->
|  trailing        =
|  truck           = 
|  bogie           = <!-- British terminology diesels and electrics -->
|  tender total     =
|  tendertruck     = <!-- USA terminology -->
|  tenderbogie     = <!-- British terminology -->
| pivotcentres     = <!-- Garratts, diesels and electrics -->
| wheelspacing     = <!-- bogies or coupled wheels with asymmetrical wheel spacing -->
| length           = {{convert|72|ft|4|in|m|1|abbr=on}}
|  over couplers   =
|  over bufferbeams=
|  body            =
| width            = {{convert|10|ft|4|in|m|1|abbr=on}}
| height           =
| axleload         =
|  leadingbogie/pony= <!-- load on leading bogie or pony wheel -->
| weightondrivers  =
| trail bogie/pony = <!-- load on trailing bogie or pony wheel -->
| locoweight       =
| fueltype         =
| fuelcap          = {{convert|2500|gal|abbr=on}}
| lubecap          =
| coolantcap       =
| watercap         = {{convert|3500|gal|abbr=on}}
| sandcap          =
| powersupply      =
| consumption      =
| watercons        =
| primemover       = [[Electro-Motive Diesel|EMD]] [[EMD 645|16-645E3]]
| rpmrange         =
|  rpmrange low    =
|  rpmrange idle   =
|  rpmrange max    =
| enginetype       = [[V16 engine|V16]] [[Diesel engine|diesel]]
| aspiration       =
| displacement     = <!-- per cylinder -->
| alternator       =
| generator        =
| tractionmotors   =
|  t/m amps 1 hr   = <!-- Power output rating per motor -->
|  t/m amps cont   = <!-- Power output rating per motor -->
| headendpower     =
| cylindercount    = 16
| cylindersize     =
| transmission     =
| gear ratio       =
| multipleworking  =
| trainheating     =
| locobrakes       = [[Railway air brake|straight air]], [[Dynamic braking (locomotive)|dynamic brakes]]
| dynamicpeakeffort=
| locobrakeforce   =
| trainbrakes      = [[Railway air brake|air]]
| reservoircap     =
| compressorcap    =
| exhaustercap     =
| coupling         =
| maxspeed         = {{convert|94-100|mph|abbr=on}}
| poweroutput      = {{convert|3000|hp|MW|abbr=on}}
|  poweroutput start=
|  poweroutput 1 hr=
|  poweroutput cont=
| tractiveeffort   =
|  t/e starting    =
|  t/e 1 hr        =
|  t/e continuous  =
| factorofadhesion =
|  f/adh starting  =
|  f/adh 1 hr      =
|  f/adh continuous=
| safety           =
| operator         = [[Amtrak]]<br />[[Atchison, Topeka & Santa Fe]]<br />[[BNSF]]
| operatorclass    =
| powerclass       =
| numinclass       = 150
| fleetnumbers     = 500–649
| officialname     =
| nicknames        =
| axleloadclass    =
| locale           = [[United States]]
| deliverydate     =
| firstrundate     =
| lastrundate      =
| retiredate       =
| withdrawndate    = 2002
| preservedunits   = One (BNSF No. 6976 - ex-Amtrak No. 644) preserved, remainder presumed scrapped
| restoredate      =
| scrapdate        =
| currentowner     =
| notes            =
|disposition      = Amtrak No. 644 currently operational in [[Boulder City, Nevada]]
}}

The ''' EMD SDP40F''' is a six-axle {{convert|3000|hp|MW|abbr=on}} [[AAR wheel arrangement#C-C|C-C]] [[Diesel–electric transmission|diesel–electric]] [[locomotive]] built by General Motors [[Electro-Motive Diesel|Electro-Motive Division]] (EMD) from 1973 to 1974. Based on Santa Fe's EMD FP45, EMD built 150 for [[Amtrak]], the operator of most intercity passenger trains in the [[United States]]. Amtrak, a private company but funded by the United States government, had begun operation in 1971 with a fleet of aging diesel locomotives inherited from various private railroads. The SDP40F was the first diesel locomotive built new for Amtrak and for a brief time they formed the backbone of the company's long-distance fleet.

A series of derailments in the mid-1970s shattered Amtrak's confidence in the locomotive, and many railroads banned it from their tracks. Multiple investigations pointed to issues with the locomotive's trucks, the weight of the water and steam generators used for train heating, the rough and poorly maintained tracks, or the harmonic  vibration of [[baggage car]]s behind the locomotive. In 1977, Amtrak decided to retire the SDP40F in favor of the [[EMD F40PH]], which was already in use on short-distance routes. Amtrak traded most of its fleet into EMD; the components were incorporated into new F40PHs. The remainder were traded to the [[Atchison, Topeka and Santa Fe Railway]] (ATSF) for use in freight service. The Santa Fe rebuilt the locomotives and designated them '''SDF40-2'''. The [[Burlington Northern Santa Fe Railway]] (BNSF), successor to the Santa Fe, retired them in 2002. One of them is preserved, that one being ex-Amtrak No. 644.

==Background==
{{main|Amtrak#1970s: the Rainbow Era}}
Amtrak assumed operation of most intercity rail passenger service in the [[United States]] on May 1, 1971. Until then such services were operated by [[List of railroads eligible to participate in the formation of Amtrak|various private railroads]]. The private railroads chose to retain their second generation passenger locomotives for freight service, or to operate the various [[commuter rail|commuter]] services which, by law, did not pass to Amtrak. To operate these intercity services the Amtrak had to buy or lease from the private railroads whatever locomotives remained. This left Amtrak with an aging and mechanically incompatible fleet of diesel locomotives. The mainstays of Amtrak's road diesel fleet were veteran [[EMD E8|E8]]s, [[EMD E9|E9]]s, [[EMD F3|F3B]]s, [[EMD F7|F7]]s, and [[EMD FP7|FP7]]s. These ranged from 7 to 24 years old and were due for replacement.<ref name="Holland-2009-57">{{Harvnb|Holland|2009|p=57}}</ref><ref>{{Harvnb|Thoms|1973|pp=38–39}}</ref>

==Design==
[[File:AMTK 551 with 11 at NewhallMay75x (11847875626).jpg|thumb|left|alt=Red and silver locomotive|No. 551 at [[Newhall Yard]] in [[San Jose, California]], with the ''[[Coast Starlight]]'' in 1975. The later SDP40Fs were distinguished from the first 40 by lower-profile cooling fans.]]
The SDP40F was a full-width [[cowl unit]]. It was based on the [[EMD FP45]] passenger locomotive and [[EMD SD40-2]] freight locomotive. All three shared the [[EMD 645]]E3 [[diesel engine|diesel]] [[Prime mover (locomotive)|prime mover]], which developed {{convert|3000|hp|MW|abbr=on}}.<ref>{{Harvnb|Pinkepank|1973|p=125}}</ref><ref name="McDonnell 2015 155">{{Harvnb|McDonnell|2015|p=155}}</ref> The locomotive had a gear ratio of 57:20. Maximum speed at full horsepower was {{convert|94|mph|abbr=on}};<ref>{{Harvnb|NTSB|1976|p=19}}</ref> the locomotive exceeded {{convert|100|mph}} in tests.<ref name="Cook-February-1991-44" /> The SDP40F was fitted with a [[Leslie Controls]] SL4T (S4T) [[train horn|air horn]]. There were doubts at the time about Amtrak's long-term viability, so the locomotives were designed for easy conversion to freight locomotives should Amtrak cease operation.<ref name="Holland-2009-57" /><ref>{{Harvnb|Solomon|2000|p=162}}</ref>

In the early 1970s Amtrak's passenger car fleet was [[steam generator (railroad)|steam-heated]]; Amtrak's requirement called for two steam generators.<ref>{{Harvnb|Ingles|1975|p=25}}</ref> These were located at the rear of the locomotive. Forward of the generators was a {{convert|1350|gal|adj=on}} water tank. This tank rested above the floorline. The lateral motion of the water within was later implicated in several [[derailment]]s. The primary underbody tank was split between water and diesel fuel, carrying {{convert|2150|gal}} of water and {{convert|2500|gal}} of diesel.<ref>{{Harvnb|Cook|1991a|p=64}}</ref>{{refn|group=note|Sources agree on a {{convert|6000|gal|adj=on}} total tank capacity and {{convert|3500|gal|adj=on}} water capacity, but some say the carbody tank was {{convert|1500|gal}}. EMD's specifications manual says 1350 gallons.<ref name="Cook-February-1991-44" /><ref name="Holland 2009 58">{{Harvnb|Holland|2009|p=58}}</ref><ref>{{Harvnb|NTSB|1976|p=17}}</ref>}} Provision was made for eventual conversion to [[head-end power]] (HEP), but it was never carried out.<ref>{{Harvnb|Cook|1991b|p=47}}</ref>

EMD based the SDP40F name on the existing [[EMD SDP40|SDP40]]. Several years earlier, EMD had made similar versions of the [[EMD SDP45|SDP45]] and [[EMD SD45|SD45]] in a full-width cowl unit, which it named [[EMD FP45|FP45]] and [[EMD F45|F45]]. Although the SDP40F was externally nearly identical to the FP45,<ref>{{Harvnb|McDonnell|2015|pp=154–155}}</ref> EMD chose not to give the new locomotive a similar name such as FP40. EMD wanted to avoid adding a new locomotive type to their catalog due to [[Incomes policy#United States|price controls]] in effect in the early 1970s.<ref>{{Harvnb|Graham-White|2002|pp=97–98}}</ref> The following year, the [[EMD F40C|F40C]] name was used for a similar locomotive ordered by the [[Chicago, Milwaukee, St. Paul and Pacific Railroad]] (the "Milwaukee Road"), equipped with HEP instead of steam generators.<ref>{{Harvnb|McDonnell|2015|p=156}}</ref>

There were several minor differences between the first 40 locomotives built and later examples. The most important was the installation of lower-profile cooling fans and [[train horn|air horns]] to avoid [[Loading gauge|clearance]] problems in the Eastern US.<ref name="Harvnb|Cook|1991b|p=42">{{Harvnb|Cook|1991b|p=42}}</ref>

==History==
{{Stack|
[[File:Amtrak Coast Starlight-Daylight 1974 postcard.jpg|thumb|right|An [[EMD E8]] on the ''[[Coast Starlight]]'' in 1974. Amtrak planned to replace its E-units with the SDP40F]]
[[File:Southwest Limited Photos (28780374161).jpg|thumb|right|[[EMD F40PH]]R with an SDP40F on the head of the ''[[Southwest Chief|Southwest Limited]]'' 1981. The SDP40Fs time with Amtrak was drawing to a close]]
}}
Amtrak ordered 150 SDP40Fs, in two batches. The first order, placed on November 2, 1972, was for 40 locomotives, at a cost of $18 million. A second order, for 110 locomotives at $50 million, followed on October 12, 1973.<ref>{{Harvnb|Congress|1974|p=41}}</ref> These orders were Amtrak's first for new-build locomotives.<ref>{{Harvnb|Ingles|1975|p=23}}</ref> Amtrak deployed the original 40 locomotives on long-distance trains in the [[Western United States]]. The locomotives entered revenue service on June 22, 1973, hauling the ''[[Super Chief]]'' from [[Chicago]] to [[Los Angeles]] over the [[Atchison, Topeka and Santa Fe Railway]]. SDP40Fs were also used on the [[Burlington Northern Railroad]].<ref name="Harvnb|Cook|1991b|p=42"/> The arrival of the second order enabled Amtrak to deploy the SDP40Fs throughout the country, displacing the inherited E-units.<ref>{{Harvnb|Ingles|1975|pp=26–27}}</ref>

=== Derailments ===
In late 1975 J. David Ingles called the SDP40Fs the "stars of Amtrak's long-distance trains,"<ref>{{Harvnb|Ingles|1975|p=24}}</ref> but engine crews reported that the locomotives rode poorly compared to the E-units they had replaced.<ref>{{Harvnb|Cook|1991b|pp=43–44}}</ref> Even as Amtrak and EMD investigated the ride quality, the SDP40F was involved in a series of derailments that led to the end of its career as a passenger locomotive. Between 1974 and 1976 the [[Federal Railroad Administration]] (FRA) identified thirteen incidents for which the locomotive was responsible. None of the incidents were serious, but their frequency was a concern. Most of the derailments occurred on trains with two SDP40Fs on the front and at least one trailing baggage car. While the rear truck of the second locomotive and the front truck of the baggage car were pinpointed as the source of the derailment, the actual cause of the derailments was unclear.<ref name="Cook-February-1991-44">{{Harvnb|Cook|1991b|p=44}}</ref>

EMD, Amtrak, the [[Association of American Railroads]] (AAR), and the FRA tested the locomotive thoroughly, with suspicion falling on the "hollow bolster" truck design. In the end, the investigators theorized that the steam generators and water tank may have made the rear of the engine too heavy and created too much lateral motion.<ref name="McDonnell 2015 155"/> Later FRA investigations concluded that the actual culprit was the light weight of the baggage cars, which caused harmonic vibrations when placed directly behind the much heavier SDP40F.<ref>{{harvnb|Graham-White|2002|pp=105; 107}}</ref> A contributing factor was the sometimes poor quality of track the locomotive operated over.<ref>{{Harvnb|Sanders|2006|p=126}}</ref>

Amtrak took several corrective measures, including operating with a reduced speed on curves, emptying the smaller of the two water tanks to reduce lateral motion, and making various alterations to the trucks.<ref name="Holland 2009 58" /><ref name="Cook-February-1991-44" /><ref>{{Cite web |url=https://www.ntsb.gov/safety/safety-recs/recletters/R77_36.pdf |title=Safety Recommendations: R-77-36 |website=National Transportation Safety Board |date=November 7, 1977}}</ref> The measures helped, but the trouble continued. Several railroads, including the Burlington and the [[Chesapeake and Ohio Railway]] (C&O), banned the "rail breakers" from their tracks; they were suspected to be causing the spreading of rails because of their lateral swaying, which may have contributed to the derailments.<ref>{{Harvnb|Cook|1991b|p=46}}</ref> For the Chicago–Seattle ''[[Empire Builder]]'', the speed restrictions added 6 hours to what had been a 46-hour schedule.<ref>{{Harvnb|Sanders|2006|p=160}}</ref> Another important development was the [[Blizzard of '77#Winter of 1976–1977|unusually harsh winter of 1976–1977]], which sidelined many of Amtrak's aging steam-heated coaches. Amtrak suspended numerous routes and pressed the new HEP-equipped [[Amfleet|Amfleet I]] coaches, designed for short runs, into service. The new [[EMD F40PH]], intended for short-distance service and equipped with HEP, handled these trains.<ref>{{Harvnb|Graham-White|Weil|1999|p=56}}</ref>

In the spring of 1977 Amtrak faced a power crisis. In addition to the SDP40Fs derailing, Amtrak was having trouble with two other six-axle designs. The [[GE E60|GE E60CP and E60CH]] electric locomotives were having derailment problems. The [[GE P30CH]] had the same truck design as E60s and rode poorly, although it did not exhibit the same tendency to derail.<ref>{{Harvnb|Holland|2009|p=59}}</ref> Amtrak decided to abandon the SDP40F in favor of the F40PH, a four-axle design with none of the riding problems of the six-axle locomotives. Amtrak traded 40 SDP40Fs back to EMD. Components including the prime mover were installed into an F40PH's frame.<ref>{{Harvnb|Cook|1991b|p=49}}</ref> Between 1977 and 1987 Amtrak traded 132 of the SDP40Fs back to EMD for F40PHRs. The SDP40F remained in service on the Santa Fe longer than elsewhere, although the arrival of HEP-equipped [[Superliner (railcar)|Superliner]] cars on the Western routes displaced them from there as well. The last SDP40Fs left the Amtrak roster in 1987. The remaining Amtrak SDP40Fs that weren't sold to the ATSF (seen below) are presumed to have been scrapped.<ref>{{Harvnb|Cook|1991b|p=50}}</ref>

===Freight use===
[[File:ATSF 5261 CA Caliente.jpg|thumb|right|Santa Fe SDF40-2 {{Abbr|No.|Number}} 5261 in [[California]] in the late 1980s.]]
In 1984 Amtrak, low on [[switcher|light-duty power]], traded 18 SDP40Fs to the Santa Fe for 43 switchers: 25 [[CF7]]s and 18 [[SSB1200]]s. Santa Fe rebuilt the traded locomotives for freight use. Modifications included removing the steam generators and regearing for lower speed.<ref>{{Harvnb|Danneman|1986|p=52}}</ref> The locomotives were also given front steps and platforms, and notched noses in order to improve boarding access. The rebuilt locomotives were designated SDF40-2.<ref>{{Harvnb|Foster|1996|p=88}}</ref> The SDF40-2s continued in service with the [[BNSF Railway]], successor to the Santa Fe, until their retirement in 2002.<ref>{{Harvnb|Lustig|2003|p=29}}</ref>

===Preservation===
One SDF40-2, ex-Amtrak No. 644 (later ATSF and then BNSF 6976), was acquired by Dynamic Rail Preservation Inc. and is in [[Boulder City, Nevada]] having been previously displayed in [[Ogden, Utah]].<ref name="trn201405" /><ref>{{Cite web |url=http://trn.trains.com/news/news-wire/2019/01/06-historic-diesels-relocated-from-utah-to-nevada |title=Historic Diesels relocated from Utah to Nevada |last=Mitchell |first=Alexander D. IV |date=January 6, 2019 |website=Trains News Wire |access-date=January 7, 2019 |archive-date=August 30, 2020 |archive-url=https://web.archive.org/web/20200830184420/https://trn.trains.com/news/news-wire/2019/01/06-historic-diesels-relocated-from-utah-to-nevada }}</ref> It was restored to its [[Maersk|Maersk Sealand]] livery and returned to operation in November 2019, now running on the [[Nevada State Railroad Museum Boulder City|Nevada Southern Railroad]].<ref>{{Cite web|title=DynaRail - Updates|url=http://dynarail.org/updates.html|website=dynarail.org|access-date=September 7, 2019|archive-date=January 4, 2020|archive-url=https://web.archive.org/web/20200104070358/http://dynarail.org/updates.html}}</ref><ref>{{Cite web|url=https://www.facebook.com/dynarail/photos/a.632487670174843/2654490161307907/?type=3&theater|title=Dynamic Rail Preservation 6976 returns to service|website=facebook.com}}</ref>
{{clear}}

== Notes ==
{{Reflist|group=note}}

== Footnotes ==
{{Reflist|30em|refs=
<ref name="trn201405">{{cite web | last=Franz | first=Justin | title=With the torches fired up, railfans hope to save F45 in the eleventh hour | work=[[Trains (magazine)|Trains News Wire]] | date=May 22, 2014 | access-date=April 2, 2017 | url=http://trn.trains.com/news/news-wire/2014/05/with-the-torches-fired-up-railfans-hope-to-save-f45-in-the-eleventh-hour}} {{subscription required}}</ref>
}}

== References ==
* {{cite journal| volume = 10| issue = 1| pages = 58–67| last = Cook| first = Preston| title = The SDP40F: From Varnish to Vanquished (Part 1)| journal = [[Railfan & Railroad]]| date = January 1991 | issn=0163-7266 | ref={{Harvid|Cook|1991a}} }}
* {{cite journal| volume = 10| issue = 2| pages = 42–50| last = Cook| first = Preston| title = The SDP40F: From Varnish to Vanquished (Part 2)| journal = [[Railfan & Railroad]]| date = February 1991 | issn=0163-7266 | ref={{Harvid|Cook|1991b}} }}
* {{cite journal | last=Danneman | first=Mike | title=Who would have guessed! | journal=[[Trains (magazine)|Trains]] | volume=46 | issue=4 | date=February 1986 | pages=52–53 | issn=0041-0934 }}
* {{Foster-Field Guide}}
* {{cite book | title=Electro-Motive Division's Classic Cowl Units | last=Graham-White | first=Sean | year=2002 |publisher=Four Way West Publications |location=La Mirada, CA | isbn=1-885614-53-5 }}
* {{cite journal | title =The little locomotive that did | pages=52–61 | journal=[[Trains (magazine)|Trains]]| last1=Graham-White |first1=Sean | last2=Weil | first2=Lester | date=December 1999  | volume=59 | issue=12 | issn=0041-0934 }}
* {{cite journal | last=Holland | first=Kevin J. | title=Amtrak's F40PH: From dark clouds, a silver lining | journal=Railroad History | date=Spring–Summer 2009 | issue=200 | pages=56–65 }}
* {{Cite journal| volume = 36| issue = 2| pages = 22–29| last = Ingles| first = J. David| title = The power behind the pointless arrow| journal = [[Trains (magazine)|Trains]]| date = December 1975 | issn=0041-0934 }}
* {{Cite journal| volume = 63| issue = 1| page = 29| last = Lustig| first = David| title = End of the line for SDP40Fs| journal = [[Trains (magazine)|Trains]]| date = January 2003 | issn=0041-0934 }}
* {{McDonnell-Locomotives-2nd}}
* {{cite book | title=Derailment of Amtrak train on Louisville and Nashville Railroad, Pulaski, Tennessee, October 1, 1975 | series=Railroad accident report |year=1976| author-link=National Transportation Safety Board | author=NTSB | oclc=9560324 | url=https://www.ntsb.gov/investigations/AccidentReports/Reports/RAR7606.pdf }}
* {{Pinkepank diesel spotters guide 2}}
* {{Sanders-Heartland}}
* {{Solomon-American Diesel}}
* {{cite book | title=Reprieve for the Iron Horse: The AMTRAK Experiment–Its Predecessors and Prospects | publisher=Claitor's Publishing Division | last=Thoms|first=William E. | year=1973 | location=Baton Rouge, LA  | oclc=1094744 }}
* {{cite book | title=Amtrak authorization—1975 hearings before the Subcommittee on Transportation and Aeronautics of the Committee on Interstate and Foreign Commerce, House of Representatives, Ninety-third Congress, second session, on H.R. 15427 and H.R. 15428 ... June 17 and 20, 1974 | author=United States. Congress. House. Committee on Interstate and Foreign Commerce. Subcommittee on Transportation and Aeronautics | date=1974 | location=Washington, D.C. | publisher=[[United States Government Printing Office]] | url=http://memory.loc.gov/service/ll/pdbs/pdbs13a/PDBS_300_test/00078709959/00078709959.pdf | ref={{Harvid | Congress | 1974}} }}

==External links==
{{commons category|EMD SDP40F locomotives}}
* [http://atsf.railfan.net/cowls/sdp40f.html Santa Fe SDF40-2s] on Santa Fe Subjects
* [https://www.thedieselshop.us/Data%20EMD%20SDP40F.HTML EMD SDP40F Data Sheet]
{{Amtrak rolling stock}}
{{EMD cab and cowl}}
{{Santa Fe Cowls|state=collapsed}}

{{DEFAULTSORT:Emd Sdp40f}}
[[Category:Amtrak locomotives]]
[[Category:Electro-Motive Division locomotives|SD40PF]]
[[Category:C-C locomotives]]
[[Category:Passenger locomotives]]
[[Category:Diesel–electric locomotives of the United States]]
[[Category:Railway locomotives introduced in 1973]]
[[Category:Standard-gauge locomotives of the United States]]
[[Category:American Passenger Locomotives]]
[[Category:Atchison, Topeka and Santa Fe Railway locomotives]]