GE "Super 7" Locomotives (Super-7N And Super-7R)

Last Revised: December 21, 2021

By: Adam Burns

The "Super 7 Series," a name coined by Monongahela Railway president Paul Reistrup, according to Brian Solomon's book "GE Locomotives," was a rebuild program implemented during the 1980s to breathe new life into older Universal and early "Dash 7" models.

With sales ramping up for its latest "Dash 8" line, and the expense of new locomotives climbing, GE believed a rebuild series would bring in new buyers while providing them a power plant that featured the latest in electronics and components.

Interestingly, this concept was relatively new at the time; while Electro-Motive had rebuilt some older Baldwins and Alcos with EMD prime mover, and upgraded a few of its own first-generation Geeps, the company had never offered a true rebuild program of like-new locomotives.

The closest in existence then included companies such as Morrison-Knudsen and Precision National, which rebuilt a variety of first, and early second, generation locomotives from Alco and EMD.

Unfortunately, the domestic market for the Super 7s never took off, thanks largely to a saturated market of older first generation EMDs that could be acquired for a fraction of the price.  

Interestingly, Super 7s did gain a large following in Mexico where Ferrocarriles Nacionales de México acquired a large fleet of six-axle variants, the C30-S7, during the early 1990s.

Monongahela "Super 7's" layover between assignments in Brownsville, Pennsylvania on October 5, 1990; #2302 began its career as Western Pacific U23B #2252 while #2300 as Western Pacific U23B #2254. Warren Calloway photo.


Super 7 History And Background

The Monongahela Railway was the only American line to show interest in GE's Super 7 series.  The MGA, then-owned by CSX and Conrail, was a regional coal carrier situated in north-central West Virginia and southwestern Pennsylvania.

It ultimately picked up eleven examples, #2300-2310.  In addition, Roberval & Saguenay of Ontario acquired three units.  The MGA locomotives were all former Western Pacific U23Bs while Ferrocarriles Nacionales de México's were rebuilt from former U30Cs, U33Cs, U36Cs, U36CGs, C30-7s, and C36-7s.

Monongahela Railway "Super 7" #2300 was photographed in Brownsville, Pennsylvania by Warren Calloway between assignments on October 15, 1990.

As Greg McDonnell notes in his book, "U-boats," former Western Pacific U23B #2263 was the chassis selected to become the original "Super 7" variant.

To keep costs down, GE reused the prime mover, 752 traction motors, trucks, and frames.  The company, however, upgraded the locomotive with a new standard comfort cab, Dash 8 specifications, modern toilet, refrigerator, and GE's SENTRY wheel-slip control system.  The company detailed this system in the following:

"The SENTRY system used traction-motor shaft speed sensors in place of older axle-mounted systems.  The motor shaft sensors were as much as six times more sensitive to speed fluctuations, allowing for more detailed corrections to wheel slip and a better application of sand to the rail. 

Seen here at rural Clarksville, Pennsylvania are Monongahela B23-7R's moving an empty string of hoppers towards Emerald Mine on October 14, 1991. The lead unit began its career as Western Pacific U23B #2264. Wade Massie photo.

Depending on the severity of wheel slip, the SENTRY system would automatically sand the rail and make small, calculated reductions to motor output."

With GE's Erie plant at record capacity outshopping new Dash 8 locomotives, the company acquired the old Montreal Locomotive Works facility in Montreal, Quebec to handle new "Super 7" builds.  

Interestingly, this facility had been American Locomotive's Canadian arm and completed many classic diesels, including some models never offered in the domestic United States.  At the time, Alco and GE worked closely manufacturing locomotives, a partnership which ended during the 1950s.


Super 7 Series Data Sheets

B23-S7 (Super7-23B)

Entered Production3/1989 (General Electric #2000)
Years Produced3/1989 - 2/1991
GE ClassB23-S7 (Super7-23B)
Engine7FDL12 (12 cylinder)
Engine BuilderGeneral Electric
Horsepower2250
RPM1050
Length60' 2"
Height (Top Of Rail To Top Of Cab)14' 11 1/2"
Width10' 3"
Weight272,000 Lbs
Fuel Capacity2,900 Gallons
Air Compressor3CDC (Westinghouse)
Air Brake Schedule26L (Westinghouse)
TrucksB-B
Truck TypeFloating Bolster FB2 (GE)
Truck Wheelbase9' 4"
Wheel Size40"
Traction Motors752 (4), GE
Traction AlternatorGTA11 (AC), GE
Auxiliary GeneratorGY27, GE
MU (Multiple-Unit)Yes
Dynamic BrakesYes
Gear Ratio83:20
Tractive Effort (Starting)85,800 Lbs
Tractive Effort (Continuous)64,000 Lbs at 10.2 mph
Top Speed70 mph

C30-S7 (Super7-30C)

Entered Production5/1989 (General Electric #3000)
Years Produced5/1989 - 6/1993
GE ClassC30-S7 (Super7-30C)
Engine7FDL16 (16 cylinder)
Engine BuilderGeneral Electric
Horsepower3000
RPM1050
Length67' 3"
Height (Top Of Rail To Top Of Cab)15' 4 1/2"
Width9' 1"
Weight410,000 Lbs
Fuel Capacity3,000 Gallons
Air Compressor3CDC (Westinghouse)
Air Brake Schedule26L (Westinghouse)
TrucksC-C
Truck TypeFloating Bolster FB3 (GE)
Truck Wheelbase13' 7"
Wheel Size40"
Traction Motors752 (6), GE
Traction AlternatorGTA11AC, GE
Auxiliary GeneratorGY27, GE
MU (Multiple-Unit)Yes
Dynamic BrakesYes
Gear Ratio83:20
Tractive Effort/Starting105,000 Lbs
Tractive Effort/Continuous96,000 Lbs at 9.1 mph
Top Speed70 mph


Super-7 Series Production Roster

B23-S7 (Super7-23B)

Owner Road Number Serial Number Order Number Completion Date Rebuild Location History
General Electric (GECX)20003840925253/1989GE: Erie, PAEx-Western Pacific U23B #2263
General Electric (GECX)20013839725253/1989Morrison-Knudsen: Boise, IDEx-Western Pacific U23B #2251
General Electric (GECX)20023840325253/1989Morrison-Knudsen: Boise, IDEx-Western Pacific U23B #2257
Monongahela Railway23003840025259/1989GE: Montreal, QCEx-Western Pacific U23B #2254
Monongahela Railway230138401252510/1989GE: Montreal, QCEx-Western Pacific U23B #2255
Monongahela Railway230238398252511/1989GE: Montreal, QCEx-Western Pacific U23B #2252
Monongahela Railway230338404252511/1989GE: Montreal, QCEx-Western Pacific U23B #2258
Monongahela Railway230438399252512/1989GE: Montreal, QCEx-Western Pacific U23B #2253
Monongahela Railway230538410252512/1989GE: Montreal, QCEx-Western Pacific U23B #2264
Monongahela Railway23063840325253/1989Morrison-Knudsen: Boise, IDEx-GE Demonstrator #2001
Monongahela Railway23073840825252/1990GE: Montreal, QCEx-Western Pacific U23B #2262
Monongahela Railway23083840625252/1990GE: Montreal, QCEx-Western Pacific U23B #2260
Monongahela Railway23093840725252/1990GE: Montreal, QCEx-Western Pacific U23B #2261
Monongahela Railway23103841125253/1990GE: Montreal, QCEx-Western Pacific U23B #2265
Roberval & Saguenay (Quebec)503752825166/1990GE: Montreal, QCEx-Santa Fe U23B #6337
Roberval & Saguenay (Quebec)5137529251612/1990GE: Montreal, QCEx-Santa Fe U23B #6338
Roberval & Saguenay (Quebec)524153125142/1991GE: Montreal, QCEx-Missouri Pacific U23B #2287

All Monongahela "Super 7s" rode on Blomberg trucks.  These units were all ex-Western Pacific U23B's, which the railroad had equipped with Blombergs from trade-in EMD units.

C30-S7 (Super7-30C)

Owner Road Number Serial Number Order Number Completion Date Rebuild Location History
General Electric (GECX)30003821318615/1989Morrison-Knudsen: Boise, IDEx-Southern U33C #3811
General Electric (GECX)30013821418615/1989Morrison-Knudsen: Boise, IDEx-Southern U33C #3812
General Electric (GECX)30024096118426/1989Morrison-Knudsen: Boise, IDEx-Union Pacific U30C #2956
General Electric (GECX)30033991818716/1990GE: Montreal, QCEx-Milwaukee Road U30C #5653
General Electric (GECX)30043992018716/1990GE: Montreal, QCEx-Milwaukee Road U30C #5655
General Electric (GECX)30053991718716/1990GE: Montreal, QCEx-Milwaukee Road U30C #5652
General Electric (GECX)30063991618716/1990GE: Montreal, QCEx-Milwaukee Road U30C #5651
General Electric (GECX)30073992218718/1990GE: Montreal, QCEx-Milwaukee Road U30C #5657
General Electric (GECX)30083991918718/1990GE: Montreal, QCEx-Milwaukee Road U30C #5654
General Electric (GECX)300938390187110/1990GE: Montreal, QCEx-Milwaukee Road U36C #8502
General Electric (GECX)301039921187110/1990GE: Montreal, QCEx-Milwaukee Road U30C #5656
Ferrocarriles Nacionales de México14000-1400139796, 39795183711/1989-12/1989Aguascalientes Shops, Mexico (NdeM)Ex-NdeM U36C #8986 and #8985
Ferrocarriles Nacionales de México14002-1400539372, 39779, 39363, 3977718371/1990-3/1990Aguascalientes Shops, Mexico (NdeM)Ex-NdeM U36C #8922, 8969, 8913, 8967
Ferrocarriles Nacionales de México14006-1400939376, 39794, 39774, 3977118375/1990-6/1990Aguascalientes Shops, Mexico (NdeM)Ex-NdeM U36C #8926, 8984, 8964, 8961
Ferrocarriles Nacionales de México14010-1401139353, 3935818375/1990San Luis Potosi Shops, Mexico (NdeM)Ex-NdeM U36C #8903 and #8908
Ferrocarriles Nacionales de México140163812518588/1990Aguascalientes Shops, Mexico (NdeM)Ex-NdeM U33Cu #8987, Nee-Southern Pacific U33C #8718
Ferrocarriles Nacionales de México14017-1401939782, 40246, 4024218379/1990Aguascalientes Shops, Mexico (NdeM)Ex-NdeM U36C #8972, 9306, 9302
Ferrocarriles Nacionales de México140203762118443/1990GE: Montreal, QCEx-Guilford U33C #659, nee-Delaware & Hudson #759
Ferrocarriles Nacionales de México140213762018443/1990GE: Montreal, QCEx-Guilford U33C #658, nee-Delaware & Hudson #758
Ferrocarriles Nacionales de México140223762118444/1990GE: Montreal, QCEx-Conrail U33C #6864, nee-Penn Central #6559
Ferrocarriles Nacionales de México14023-1402639377, 39373, 39798, 39802183711/1990Concarrel Shops, Mexico (NdeM)Ex-NdeM U36C #8927 and #8923; U36CG #8939 and #8943
Ferrocarriles Nacionales de México14027-1402839810, 3977618373/1991-4/1991Concarrel Shops, Mexico (NdeM)Ex-NdeM U36CG #8951 and U36C #8966
Ferrocarriles Nacionales de México1402943054183212/1990San Luis Potosi Shops, Mexico (NdeM)Ex-NdeM C30-7 #9601
Ferrocarriles Nacionales de México1403040250189212/1990San Luis Potosi Shops, Mexico (NdeM)Ex-NdeM U36C #9310
Ferrocarriles Nacionales de México1403143829187812/1990San Luis Potosi Shops, Mexico (NdeM)Ex-NdeM C30-7 #11038
Ferrocarriles Nacionales de México14032-1403343913, 4274918791/1991San Luis Potosi Shops, Mexico (NdeM)Ex-NdeM C30-7 #11059 and #6739
Ferrocarriles Nacionales de México140343935418372/1991San Luis Potosi Shops, Mexico (NdeM)Ex-NdeM U36C #8904
Ferrocarriles Nacionales de México140354305018372/1991Aguascalientes Shops, Mexico (NdeM)Ex-NdeM C30-7 #6797
Ferrocarriles Nacionales de México140364324018631/1991Aguascalientes Shops, Mexico (NdeM)Ex-NdeM C30-7 #9644
Ferrocarriles Nacionales de México140374264255781/1991Aguascalientes Shops, Mexico (NdeM)Ex-NdeM C36-7 #9333
Ferrocarriles Nacionales de México140384391918792/1991Aguascalientes Shops, Mexico (NdeM)Ex-NdeM C30-7 #11065
Ferrocarriles Nacionales de México140394320618633/1991Aguascalientes Shops, Mexico (NdeM)Ex-NdeM C30-7 #9611
Ferrocarriles Nacionales de México140404366618763/1991Aguascalientes Shops, Mexico (NdeM)Ex-NdeM C30-7 #11016
Ferrocarriles Nacionales de México140414320818634/1991Aguascalientes Shops, Mexico (NdeM)Ex-NdeM C30-7 #9613
Ferrocarriles Nacionales de México14042-1404439357, 39360, 3936118377/1991-8/1991San Luis Potosi Shops, Mexico (NdeM)Ex-NdeM U36C #8907, 8910, 8911
Ferrocarriles Nacionales de México14045-1405039364, 39805, 39770, 39359, 3978518376/1991-8/1991Aguascalientes Shops, Mexico (NdeM)Ex-NdeM U36C #8914 and #8915; U36CG #8946; U36C #8960, 8909, 8975
Ferrocarriles Nacionales de México14051-1405439384, 39807, 39801, 3979018371/1992-2/1992Aguascalientes Shops, Mexico (NdeM)Ex-NdeM U36C #8934; U36CG #8948 and #8942; U36C #8980
Ferrocarriles Nacionales de México14055-1405940320, 40319, 40325, 40323, 4032118941/1992-6/1992Empalme Shops, Mexico (NdeM)Ex-Ferrocarril del Pacífico U36C #413, 412, 418, 416, 414
Ferrocarriles Nacionales de México14060-1406439787, 39768, 39387, 39792, 3978818373/1992-5/1992Aguascalientes Shops, Mexico (NdeM)Ex-NdeM U36C #8977, 8958, 8937, 8982, 8978
Ferrocarriles Nacionales de México14065-1406637697, 3769618437/1992Empalme Shops, Mexico (NdeM)Ex-Ferrocarril del Pacífico U30C #407 and #406
Ferrocarriles Nacionales de México140673737118167/1992Empalme Shops, Mexico (NdeM)Ex-Ferrocarril del Pacífico U30C #403
Ferrocarriles Nacionales de México14068-1407539383, 39773, 39798, 39810, 39778, 39775, 39769, 3981518376/1992Aguascalientes Shops, Mexico (NdeM)Ex-NdeM U36C #8933, 8963; U36CG #8939 and #8951; U36C #8968, 8965, 8959; U36CG #8956
Ferrocarriles Nacionales de México1407643673182311/1992Aguascalientes Shops, Mexico (NdeM)Ex-NdeM C30-7 #11128
Ferrocarriles Nacionales de México14077-1407840249, 4024718921/1993-3/1993Aguascalientes Shops, Mexico (NdeM)Ex-NdeM U36C #9309 and #9307
Ferrocarriles Nacionales de México140794267818782/1993Aguascalientes Shops, Mexico (NdeM)Ex-NdeM C30-7 #6728
Ferrocarriles Nacionales de México14080-1408143823, 4418118231/1993-2/1993San Luis Potosi Shops, Mexico (NdeM)Ex-NdeM C30-7 #11032 and #11071
Ferrocarriles Nacionales de México140824367318772/1993San Luis Potosi Shops, Mexico (NdeM)Ex-NdeM C30-7 #11028
Ferrocarriles Nacionales de México140834382718783/1993San Luis Potosi Shops, Mexico (NdeM)Ex-NdeM C30-7 #11036
Ferrocarriles Nacionales de México1408437372181610/1992Empalme Shops, Mexico (NdeM)Ex-Ferrocarril del Pacífico U30C #404
Ferrocarriles Nacionales de México1408543618187311/1992Empalme Shops, Mexico (NdeM)Ex-Ferrocarril del Pacífico C30-7 #452
Ferrocarriles Nacionales de México14086-1408740316, 40324189412/1992Empalme Shops, Mexico (NdeM)Ex-Ferrocarril del Pacífico U36C #409 and #417
Ferrocarriles Nacionales de México140884361518735/1992Empalme Shops, Mexico (NdeM)Ex-Ferrocarril del Pacífico C30-7 #449
Ferrocarriles Nacionales de México140894423618264/1993San Luis Potosi Shops, Mexico (NdeM)Ex-NdeM C30-7 #11096
Ferrocarriles Nacionales de México140904507055784/1993San Luis Potosi Shops, Mexico (NdeM)Ex-NdeM C36-7 #9330
Ferrocarriles Nacionales de México140914382618784/1993San Luis Potosi Shops, Mexico (NdeM)Ex-NdeM C30-7 #11035
Ferrocarriles Nacionales de México140923977218374/1993Aguascalientes Shops, Mexico (NdeM)Ex-NdeM U36C #8962
Ferrocarriles Nacionales de México140934227418724/1993Aguascalientes Shops, Mexico (NdeM)Ex-NdeM C36-7 #9322
Ferrocarriles Nacionales de México14094-1409639811, 39797, 3981318375/1993-6/1993Aguascalientes Shops, Mexico (NdeM)Ex-NdeM U36CG #8952, 8938, 8954
Ferrocarriles Nacionales de México140974032218946/1993Empalme Shops, Mexico (NdeM)Ex-Ferrocarril del Pacífico U36C #415
Ferrocarriles Nacionales de México140984248018756/1993Empalme Shops, Mexico (NdeM)Ex-Ferrocarril del Pacífico C36-7 #426

Sources:

  • Solomon, Brian. GE Locomotives: 110 Years Of General Electric Motive Power. St. Paul: MBI Publishing, 2003.

  • McDonnell, Greg. U-boats.  Toronto: Stoddart Publishing, 1994.


Now in Conrail colors, a former Monongahela "Super 7" unit leads a long string of local power towards Conway Yard as the consist rolls through Glenfield, Pennsylvania for light maintenance servicing on June 22, 1997. Wade Massie photo.

In addition, GE subcontracted work out to Morrison-Knudsen's plant in Boise, Idaho.  In fact, MK completed two of the three demonstrators General Electric had built.

The Monongahela acquired one of these demos while the other two were never sold.  From an outward appearance, Super 7's appeared almost nothing like their U-boat predecessors while internally they carried many of the same components.

They became a popular subject on the late-era Monongahela and were the final locomotives to adorn the railroad's classic grey livery with the large stylized "M" adorning the nose and carbody.

The units spent a few years in their original livery before being repainted into Conrail blue.  They were subsequently split up between Norfolk Southern and CSX after the Conrail takeover.  Today, they are scattered around the country at various short lines and private industries.

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