EMD's Dual Purpose SDP

SP #3207 with Rose Bowl special at Cabazon, CA in January 1987 -- (John Shine photo)


Several U.S. railroads by the early 1960s were wrestling with issue of how to replace their aging passenger locomotive fleets. Investing in new E9s or FP9 cab units was far from a popular option, given declining passenger train revenues. Moreover, any capital investment in new motive power was surely going to be evaluated in terms of overall flexibility, which was hardly a cab unit's strong point.

The first indication that a practical solution had been achieved appeared in the Summer of 1964 with introduction by EMD of a new six-axle, 2500-horsepower locomotive, dubbed the SDP 35. Seaboard Air Line (SAL) was first to sign a purchase order; they acquired 20 of the 567-V16 powered model (#1100-1119). Atlantic Coast Line (ACL) followed-up with an order for a single unit (#550); the decision was influenced to some degree by the on-going merger discussions between the two long-time competing railroads. Union Pacific's purchase of ten of the dual-purpose locomotives in 1965 brought production of the SDP35 to a close. However, 6500 miles to the west,The Korean National Railroad was interested in a comparable 2000-hp version, and thus the 567-driven SDP28 was born.

Interestingly, KNR was the single largest buyer of any SDP model, including the 3000-hp SDP40 and the 20-cylinder, 3600-hp SDP45, both of which were driven by EMD's new 645 engine that had been introduced at the start of 1966. KNR's purchase called for forty non-turbocharged SDP38s; the 2000-hp locomotives were delivered during 1967/1968.

After retirement from mainline service, only a few of the dual-purpose SDPs found a place in the second-hand market, and that story will be covered next month. It is also not surprising, given their limited production, only two were targeted by preservation groups. SAL SDP35 #1114, part of the the original SDP order, became a permanent display outside the train station at Hamlet, South Carolina. And a Burlington Northern SDP40 (ex-Great Northern #325) found a long-term home at the Minnesota Transportation Museum.

Perhaps, the most notable of all SDPs is Burlington Northern SDP40 #1976, which wore a U.S Bicentennial-inspired red, white and blue paint-scheme during a four-year-long celebration. The six-axle passenger hauler had been built originally for GN as #323.


Photo Gallery: The purpose of the following collection of photos is to portray (where possible) the dual-service nature of the SDP on the railroads that were original purchasers. By the way, there has been no reference here to Erie Lackawanna's popular SD45s with the elongated carbody, nor Louisville & Nashville's stretched SD35s. It is because they were not dual-purpose SDPs; most notably both lacked a steam generator. EL ordered several modified SD45s with a 5000-gallon fuel tank rather than the standard 4000-gallon tank. A longer frame and carbody were necessary to support an "olympic-size" fuel tank. The L&N units housed new "LocoTrol" equipment (master/slave technolgy) in the rear-end rather than a boiler.
SDP45
GN #330 with eastbound "Empire Builder" leaves Seattle, fall of 1967.  
(Jim Lancaster photo)
BN 9857 (ex-GN 323) leads freight through Marion, OH on 27 July 1974 
(Mike Woodruff photo)
Southern Pacific 3207 with train at Ventura, CA on 27 April 1976
(Greg Brown photo)
Southern Pacific 3203 with freight at Wilmington, California in October 1987
(Joe Blackwell photo)
SDP40
Great Northern  323 with train at Vancouver, WA on 31 July 1971
(Dave Wingfield photo)
Burlington Northern 9853 (ex-GN 323) at Minot, ND on 2 October 1970 
(Keith Ardinger photo)
National de Mexico #8524 with freight at xxxxxxxx on 31 July 1971
(James C. Herold photo)

TFM/FNM 1320 on the KCS at East St. Louis, Illinois on 21 August 2009 
(Mark Mautner photo)
SDP38
KNR #6351 with express train at Taegu, Korea on 17 September 1969
(R. Craig photo)
KNR freighter #6217 (S/G-equipped) on passenger train, 3 November 1969.
(R. Craig photo)
SDP35
SAL 1114 with freight at Raleigh, NC on 1 September 1966
(Warren Calloway photo)
SAL 1102 with pasenger train #10 at Raleigh, NC on 25 July 1965
(Warren Calloway photo)
ACL 550 with freight at Hamlet, NC on xxxxxx
(Tom King photo, Warren Calloway collection)
ACL 1099 at Richmond, Virginia on 16 June 1966 
(Keith Ardinger photo)
UP #1409 helps a six-hour late w/b Zephyr in Utah during Janaury 1979
(Lee Hower photo)

UP 1404 leads unit coal train at Ontario, CA on 15 June 1980. 
(Bob Hanggie photo)
SDP28
KNR #6105 at Taegu freight yard, Korea on 12 July 1969 
(R. Craig photo)
KNR #6103 with caboose hop at Taegu, Korea in 1994
(Sheldon Perry photo)
Notable SDPs
BN #1976 (ex-GN #323) at Clyde, Yard (Chicago) 21 May 1975
(Gib Allbach photo, Chuck Zeiler) collection
Seaboard Air Line SDP35 #1114 at Hamlet, SC on 29 March 2016
(Justin Smathers photo)

* * * SDP Rosters * * *

Railroad Road Nmbr Serial Nmbr Bldr date Subsequent Ownership & Notes
SDP45 (quantity built: 18)
Great Northern 326-333 33041-33048 6-8/67
  • Re-#d at merger time to BN 9856-9863
  • BN 9856-9863 > BN 6592-6599
  • BN 6593 > NRL 6592?
  • BN 6599 > PNC #??
Southern Pacific 3200-3209 32849-32858 5-7/67
  • Retired 1988-1992
  • #3202 and 3204 to NRE and then ??

SDP40 (quantity built: 20)
Great Northern 320-325 (31592-31597) 5/66
  • At merger time re-#d BN #9850-9855 > BN 6394-6399
  • BN #9850 > BN #6395 > MRL SD40-2XR #290
  • BN #9853 > BN 6397 > BN 1976(3rd) > BN 6397 > BNSF 6325 > GCFX 3093 (rebuilt to SD40-2 in 2000)
  • GCFX 3093 > Gardendale RR 9043
  • BN 6398 & 6399 > BNSF 6326 & 6327
  • BNSF #6327 to Minnesota Transportation Museum as BN 325
National de Mexico 8522-8531 & 8532-8535 (33371-33378) (36156-36159) 5/68, 5/70
  • NdeM 8524-8527, 8532 & 8535 > FXE xxxxxxxxx
  • NdeM 8522, 8523, 8528-8531, 8533 & 8535 > FNM 8522, 8523, 8528-8531, 8533 & 8535
  • FNM 8522, 8523, 8528-8531, 8533 & 8535 > TFM 1314-1321
  • TFM 1315 & 1318 > KCSM 3009 & 3057
  • TFM 1319 rebuilt to KCS SD22ECO #2600
  • TFM 1320 rebuilt to KCS SD22ECO #2601

SDP38 (quantity built: 40)
Korea National 6351-6390 32914-32953 6-8/67
  • #6351-6373 retained S/G during the 1960s, later re-#d to 6218-6240 and S/G removed
  • #6374-6389 re-#d 6201-6216; S/G removed by railroad and placed in freight serice
  • #6390 re-#d 6217 and retained S/G during the late 1960s
  • Note: Some of this data was collected first-hand while in Korea 1968/1969; additional data was collected during an interview in 1969 with KNR chief mechanical officer. (It all needs to be confirmed.)


SDP35 (quantity built: 31)
Atlantic Coast Line 550 30531 9/65
  • ACL 550 > ACL 1099 > SCL 600/1950 > L&N 7035/1289/4540 > SBD 4540
  • Retired and scrapped
xxxxx
Seaboard Air Line 1100-1119 29339-29358 8-11/64
  • SAL 1100-1119 > SCL 601-620 > SCL 1951-1970
  • SCL 1951, 1955, 1957 & 1964 reblt to H15 SCL #5, 2, 1 & 6
  • 1952, 1954, 1956 & 1958-1961 re-#d L&N 7036 & 7038-7043
  • SCL 1953, 1962 & 1966 retired
  • SCL 1963, 1965 & 1967-1970 > SBD 4594-4599
  • L&N 7036 & 7037-7043 re-#d L&N 4541 & 4543-4548
  • L&N 4541 & 4543-4548 > SBD 4541 & 4543-4548
  • SCL #5, 2, 1, & 6 > SBD 0005, 0002, 0001 & 0006
  • SBD 0005, 0002, 0001 & 0006 > CSX 1005, 1002, 1001 & 1006
  • SBD 4541 & 4543-4548 > CSX 4541 & 4543-4548
  • SBD 4594-4599 > CSX 4594-4599

  • CSX 1002 sold to Respondek (Yankeetown Dock #11)
  • CSX 4595 restored to SAL 1114 and put on display at Hamlet, NC
Union Pacific 1400-1409 30671-30680 9/65 Retired and assumed scrapped

SDP28 (quantity built: 6)
Korean National 6301-6306 31408-31413 5/66
  • Re-#d KNR 6101-6106
  • EMD V16-645 engine replaced V16-567 powerplant in some units and operated into the mid 1990s
* * * Notes & credits * * *

Sources:

  • BN 1972 Motive Annual by F. Hol Wagner
  • Extra 2200 South Locomotive Newsletter
  • EMD Order Numbers at TrainWeb.com
  • KCS 2011 roster by FL "Dutch" Schultz
  • RRPicturesArchives.net

Original upload: 1 June 2020

Additional Contributions: Michael Richmond

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