SP AC4400’s

In 1995, the Southern Pacific Railroad purchased a fleet of brand-new locomotives from General Electric to relieve its power crisis.  SPL had been cash-strapped for years, and much of its motive power was worn out, over-used and under-maintained.  Several years after the merger with Rio Grande, SPL was just beginning to show signs of economic health, and after much testing decided to spend money on GE’s newest locomotives, which utilized alternating-current technology.

The AC4400 line was designed for high tractive effort at low speeds, just the thing for a railroad that operated a lot of coal trains in the mountains.  The three-phase AC traction motors produce maximum horsepower throughout their speed range with little or no overheating, unlike DC motors.  Heavy grades and sharp curvature in the Rockies would put the technology to the test.  A simultaneous technological development, Distributed Power (radio-control of remote locomotives, usually abbreviated DPU, for Distributed Power Unit), increased the versatility of these units.  However, DPU controls were not installed in the first 100 units of SP’s order.

SPL’s 279 new AC4400’s began arriving in May 1995, and immediately went to work in heavy service.  Although not used exclusively in coal service, they did displace most other kinds of power on coal trains in short order.  At 4,400 horsepower, 210 tons, and producing 145,000 lbs continuous tractive effort at 13.7 mph, two of these units could replace three SD-family locomotives.  Operating practices began to change too, as DPU-controlled swing and rear helpers began replacing manned helpers on most long-distance trains. Basically, it was seen as more economical than paying a crew to operate out of a dedicated helper base.

The acquisition of the AC4400’s was the last major locomotive purchase by SPL before the merger with Union Pacific, coming a mere 16 months beforehand.  As a result, they have spent most of their service life with UP.  After a few years, they were caught up in the renumbering program, just like most other power acquired in the merger.  Initially this generally meant the addition of a yellow patch on the cab with the new UP number, but over time more and more have been completely repainted.

Aesthetically, there is no denying that they were strikingly beautiful when new; even the professional railroaders of my acquaintance remark on this.  They were far more reliable than most of the existing SP power (Grand Junction crews referred to the older units as “that red-and-gray crap”).  I lamented the loss of the older power they replaced, but I didn’t have to ride on them every day– the crews thought they were a big step up.

At first, these units seemed very generic: every train had six identical-looking locomotives on it.  Later, after learning of the DPU situation, I started paying attention to the numbers. Anything numbered 100-199 indicated it was a non-controller unit.  In fact, units in this series could not lead a train that used any remotes. This did, however, create a unique niche for them.  The North Fork branch, between Grand Junction and the coal mines near Paonia, was an operation that only needed two locomotives per train, due to the profile.  Since all uphill trains were empties and all downhill trains were loads, remotes were not deemed necessary.  For many years, one found the 100’s on this branch more than any other kind of power.  (Practices began changing by 2010.)

Another spotting feature is the small white lightning-bolt emblem on the side of the nose, rear edge of the “wing”, on 200-378. This indicates a DPU controller unit.

One main difference between the SP AC4400’s and their UP counterparts (C44AC) is that the SP versions do not have an isolated cab.  Essentially, the UP units have some  additional cushioning and acoustic insulation that makes them quieter for the crews.  Espee chose not to spend the money on the option when they placed their order.  Having ridden in the cab of No. 277 between Grand Junction and Glenwood Springs, I can say that it would have been money well-spent!  The noise level in the cab when the train is running at Notch Eight is significant (you need hearing protection).

With the near-completion of the patching and repainting program, these unique units have lost some of their special identity.  In that light, I decided to create this page of images to remember the heyday of the red-and-gray AC4400’s, and to track what has become of them.

The photographs below the table are arranged chronologically. However, you may also jump directly to specific units by using the table.

(If you have photos you’d be willing to share, contact me thru the comments.)

100 101 102 103 104 105 106 107 108 109
110 111 112 113 114 115 116 117 118 119
120 121 122 123 124 125 126 127 128 129
130 131 132 133 134 135 136 137 138
141 142 142
143 144 145 * 146 147 148 149
150 151 152 153 154 155 156 157 158 159
160 161 162 163 164 165 166 167 168 169
170 171 172 173 174 175 176 177 178 179
180 181 182 183 184 185 186 187 188 189
190 191 192 193 194 195 196 197 198 199
200 201 202 203 204 205 206 207 208 209
210 211 212 213 214 215 216 217 218 219
220 221 222 223 224 * 225 226 227 228 229
230 231 232 233 234 235 236 237 238 239
240 241 242 243 244 245 246 247 248 249
250 251 252
253 254 255 256 257 258 259
260 261 262 262 263 264 265 266 267 268 269
270 271 272 273 274 275 276 277 278 279
280 281 282 283 284 285 286 287 288 289
290 291 292 293 294
295 296 297 298 299
300 301 302 303 304 305 306 307 308 309
311 312 313 314 315 316 317 318 319
320 321 322 323 324 325 326
327 328 329
330 331 332 333 334 335 336 337 338 339
340 341 342 343 344 345 346 347 348 349
350 351 352 353 354 355 356 357 358 359
360 361 362 363 364 365 366 367 368 369
370 371 372 373 374 375 376 377 378

* NOTE: Nos. 145 and 224 were wrecked at Pando on February 21, 1996.

 Top: Brand new trio of AC4400’s, Nos. 130, 219, and 200 are seen at Grand Junction on June 25, 1995.  They are a month old, and look resplendent in shiny scarlet and lark gray. Sadly, the paint formulation for the red would oxidize badly over time. UPDATED IMAGE

Bottom: Closer look at the leader, No. 130. It’s one of the non-DPU controller units. Interestingly, look at No. 219 behind it.  Although it is equipped for DPU controls, it does not yet have the lightning-bolt emblem denoting such units applied to the wing. NEW PHOTO



A pair of brand-new AC4400s are the sole power on a westbound empty coal train at Glenwood Springs on June 29, 1995.  No. 142 is in the lead. (images captured from video)
SP132_GS_1995 A pair of brand-new AC4400s are the sole power on a westbound empty coal train at Glenwood Springs on June 29, 1995.  No. 132 is trailing.(image captured from video)
SP160_1996 Three AC4400s are spotted on the yard lead south of Denver North Yard on February 24, 1996.  No. 160 is the lead unit.(image captured from video, taken from on board the Ski Train)
SP310 Three AC4400s are spotted on the yard lead south of North Yard on February 24, 1996.  No. 310 is the middle unit.(image captured from video, taken from on board the Ski Train)
SP251 Three AC4400s are spotted on the yard lead south of North Yard on February 24, 1996.  No. 251 is the trailing unit. Unlike the other two, this one is quite dirty, a typical appearance as time wore on.(image captured from video, taken from on board the Ski Train)
SP330_215-1996-08-16 A pair of AC4400’s led by No. 330 (No. 215 trailing) have an eastbound freight at Cotopaxi, CO on Aug. 16, 1996.
SP254-1996-08-16 Immediately afterwards, No. 254 led an eastbound freight past Cotopaxi, CO on Aug. 16, 1996.

(Yes I realize it’s a terrible photo…  I had to sprint for the river, clamber down through the trees and skid to a halt on the gravely slope, and take a photo while gasping for breath.)

SP362 SP103 About 7:20 AM on 8/17/96, No. 362, No. 103, and another sister are leading a westbound train.  I shot a lot of these units during a three-day  trip to Cotopaxi and the Royal Gorge area. UPDATED IMAGE
WB_Manifest Before the UP merger, SP used the AC’s to power certain manifest trains on its Central Corridor route. Here, No. 289 and a couple of older tunnel motors lead a westbound at Cotopaxi (Aug 17, 1996).  It’s three weeks until the merger, and a year before the Tennessee Pass line was severed.
SP289-081796 Here’s a closer look at No. 289 as she motors past up the canyon. (8/17/1996)
SP354-081796 No. 354 is glimpsed through the trees, leading a westbound  manifest.  If this line were to reopen, I would definitely stay at this particular campground again!
SP202 On the same day as the previous shots, two units (Nos. 202 and 102) lead an eastbound manifest at Coaldale, CO (east of Salida).  The Tennessee Pass route was very busy at this point in time.  Barely year later it was cut in two, and through traffic ceased.
Back to Table
SP357-081796 We chased this manifest train with its pair of AC4400’s all the way from Texas Creek to Coaldale, in terrible lighting (and lighning) conditions.  Here it’s rounding the curve at Coaldale, with 357 in the lead.  The shot’s a little blurry, but the colors on these yet-new and yet-clean locomotives are still vibrant.  These were classy units.
SP326-263-081896 The following day, a pair of AC4400’s with all the same numerals but different order (Nos. 326 and 263) lead an eastbounder past the campground at Cotopaxi.  No. 263 is a tad grimy at this time.
SP205 Not long after the merger, January 5, 1997 to be exact, an empty coal train with 2+2+2 Espee AC4400s roared westbound through Crescent on the Moffat Route.  Here, No. 205 is the trailing unit on the rear helper.Image is a capture from video .
SP305_19970104 Shortly after the train above passed, a loaded coal train led by No. 305 rolled eastbound through Crescent.
SP272_19970104 Same train as above; No. 272 is part of the swing helper.  Notice that the paint is still reasonably clean and shiny, despite the heavy use in coal train service.  That will change with time.
SP134 At dawn on August 3, 1998, No. 134 waits on the ready line at Grand Junction. That’s No. 117 behind her; they are a typical North Fork pair.
SP146_GJ_1998 Same day as the photo above, No. 146 is also ready to go for more coal up the North Fork branch.
SP306_GJ_1998 Again the same day, Nos. 306 and 186 wait on the service tracks at Grand Junction, in the company of a number of UP C44AC’s and a few second-generation locomotives.
SP364-Pinecliffe-98-12-26 The day after Christmas, 1998, No. 364 is running second on a westbound coal empty at Pinecliffe, Colorado.  As usual, it’s cold and windy.
SP365-Pinecliffe-98-12-26 Same train as above, the swing help consists of SP No. 365 and UP No. 7124.  At this time, some empties were still returning with remote helpers.  Later, practice changed to put all the power on empties at the head end.  [What I won’t post here is the pic of my cousin waving to the unmanned remote…]
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SP164-Pinecliffe-98-12-26 Rear remotes on the same train as above, No. 164 is leading.  However, since the 100-series lack DPU control capability, it’s actually No. 275 (below) that’s the controlling unit in this pair.  Note that all the units on this train are remarkably clean.
SP275 The day after Christmas, 1998, No. 275 is the trailing unit on a westbound coal empty at Pinecliffe.   This is one of my favorite photos.
CoalCreek-98-12-26-1 December 26, 1998– a westbound coal empty is about to split the intermediate signals at Coal Creek bridge.  SP AC4400 No. 142 is fourth back, and looks to be just along for the ride.  There were two other SP units on this train, which had all the power up front (the first three locomotives doing all the work).
SP252-WP-9908 August 1999 has No. 252 leading an eastbound coal train up the approach to West Portal.  A UP SD9043MAC is right behind.  No. 252 is shown below in nearly the same location but very different  conditions, in February 2002.



August 1999 at West Portal of the Moffat Tunnel– No. 326 leads a PSCX load up the grade.  The train is only managing about 10 mph at this point, though it accelerated as it reached the lesser grades inside the tunnel.

In this sequence, we can see the train as it negotiates the curve between Winter Park siding and the tunnel portal itself.  I can’t quite make out the number of the second unit, but it’s in the 100 series.

SP147 September 4, 1999: the Front Range was a busy place.  Here, No. 147 is the second unit on an eastbound coal train at Rocky.

This and next 3 images captured from video .

SP319 Same day, No. 319 leads a westbound CSUX train at Blue Mountain crossing.  The train was creeping up the hill towards a scheduled meet at Plainview.
SP153 No. 153 is the second unit on the CSUX train on 9/04/1999.
SP268 No. 268 is the lone mid-train helper in this 2+1+2 configuration on the CSUX train on 9/04/1999.
SP319-153 Here’s the view from across the canyon mouth as Nos. 319 and 153 lead the train into Tunnel 1.
SP222 Same day, a couple hours later, a westbound coal empty (4+2 configuration) roars out of Leyden.  No. 222 was the third unit from the front.  No. 102 is just ahead.
SP274 October 9, 2000, another coal train rolls through Crescent, led by Nos. 274 and 114.  The locomotives are starting to show the effects of several years of hard work with few washings.
SP214 On the same train as above, No. 214 is a solitary swing unit.  It has received a replacement battery box door from a UP unit.
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SP140-Fraser-1 Late in December 2000, No. 140 is second on an eastbound coal load at Fraser, CO.  The train is at the toe of the 2% grade leading up to the Moffat Tunnel, and the locomotives are starting to work harder.  By the time the last of the train was on the grade, its speed was down to a crawl.  CNW No. 8808 is leading.
SP262-GS-2001 On August 6, 2001, No. 262 leads a westbound coal empty out of the morning shadows of Glenwood Canyon.  I photographed this from our window at the Hotel Denver.  (photo enhanced to mute the  shadows…)
CCCan3 August 2001 at Coal Creek sees another PSCX coal train, led by No. 337.  This train had an interesting setup of power: three pairs of locomotives, each pair an Espee AC4400 and a UP SD9043MAC.  Evidently they were experimenting with tractive effort balancing.  The SD9043’s tend to load up quicker, leading to a jerkier start and more wheel slippage.
SP344-2001-08 Here’s a look at the rear of the same train, showing the final pair of locomotives.  No. 344 is the SP component.
SP252 2002 02 10 Wintertime in the Rockies, and No. 252 leads a load through West Portal.  This train had a mix of SP and UP power.  Probably due to the stiffer winter conditions, this train had three units on the point.  By the way, this photo appears in my book.
WP-20020210_022 Same train as above, with No. 163 and UP SD9043MAC No. 8243 cut in mid-train and pushing for all they’re worth. By now, with most of the train on the lesser 1.1% grade in the tunnel, speed has picked up from about 10 mph to closer to 20 mph.
WP-20020210_024 The rear help consists of a pair of AC4400s including SP 148 (actually, the UP unit is designated a C44AC, but it’s essentially the same hardware).  The UP unit is the controller in this pair. Now the train is up to a majestic 25 mph.  Long after it disappeared into the tunnel, a significant amount of noise and vibration could still be detected. By the way, that made for a total of seven locomotives on this train…
In November 2002 I found No. 294 on the Grand Junction ready line, right by the street.  It’s worth mentioning that, up close, these locomotives are huge, at 73′ 2″ in length and 15′ 5″ high..
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NoName04 One morning in June 2003, an eastbound coal load begins its transit of Glenwood Canyon behind Union Pacific C44AC No. 6823 and Southern Pacific AC4400 No. 107— a non-DPU-equipped unit.  They’re passing No Name at a pretty good clip, considering the grade and such.
SP138 SP158 Later the same day, over near Paonia, Nos. 138 and 158 were on a coal load passing Bowie mine.  Both are non-DPU-equipped; these units were at home on the North Fork, where remotes were seldom used until much later.
Bowie11  No. 138 leads a coal load under the bridge at Bowie.  This train had loaded at West Elk.  This shot is a good monochrome close-up of her cab.  You can see all kinds of interesting details this way.
SP310_Tabernash-2004-01-01 New Years Day 2004: this pair of units is the rear DPU set on an eastbound coal train at Tabernash, CO.   No. 310 is the SP component, as yet unpatched after nearly 8 years of UP ownership.
Crescent03 No. 271 was an early repaint, coming out of the shops on Feb 10, 2001.  Now as UP 6316, it’s leading a coal train at Crescent on November 8, 2004.  More photos from this day here.(I have been discovering a number of ex-SP AC4400’s in my photos, disguised in yellow…)
Crescent13 Let the patches begin…  It’s November 8, 2004.  UP No. 6390 is the former SP No. 260.  It’s running Tail-end Charlie on a loaded coal train at Crescent.  The sun has just gone down behind us.  The unit was given this number the previous September.
20050817_001  July 28, 2005 (nearly nine years after some of the shots at the top of this page), I encountered a pair of patched units leading a train just east of Delta.  Dirty but doing their job.  No. 6190 is the former SP 142 and No. 6193 was SP 138 (see the black/white close-up shot above).
20050817_002 An hour later, I was quite pleasantly surprised to find two unpatched units, Nos. 144 and 140, at West Elk.  These were some of the last AC4400’s in original paint and number.
UP6153-20061230 December 30, 2006: All of Colorado east of the Divide was buried under a series of blizzards that shut down the whole region, including its railroads.  Here, an eastbound coal train sat idling at Pinecliffe, nowhere to go.  The second unit on the train this evening was patched AC4400 No. 6153, the former SP 110, renumbered fifteen months earlier.(One irony of all this was that the Ski Train was cancelled because of too much snow!  Too bad they hadn’t announced that before I drove 400 miles on ice and snow to ride it.  And the bitterness continues to fester… 🙂 )
SP347 July 29, 2007 in Denver revealed a pleasant surprise: two unpatched AC4400’s.   Here is the first, No. 347, with the light on the wrong side for good photos.  It’s in North Yard, north end of the loco service area.
sp187 Buried in the yard and only half-visible, No. 187 waits for a job.  It has a patched SP SW1500 for company.
up6413 More typical of 2007, patched UP 6413 is spotted in front of the yard tower.  This was originally SP No. 367.
Back to Table
UP 6416 Basic Union Pacific C44AC, right?  Look again.  This is the former SP No. 370, leading an eastbound coal train at Sulphur on 8/9/2007. Number 370 was the first Southern Pacific AC4400 to be renumbered and repainted into this series, on May 24, 2000.
up6295 A pair of patched units are in the swing helper at Sulphur on 8/9/2007.  Our unique vantage point (on the signal mast) gives a pretty good close-up view…  These are the former Nos. 363 and 218.
up6376 One reason why I don’t like low-end digital cameras– you don’t always have good control of the shutter.  No. 6376 is the former SP 294 (listed above) and is pushing on the end of an eastbound train at Sulphur, 8/9/2007.
ex-sp124 Former No. 124, staged in Glenwood yard on 9/01/2008.  She’s starting to show her age.  [On the same day I spotted No. 352, unpatched, just west of here. Unfortunately I couldn’t get the camera working in time…]
ex-sp328 Former No. 328, DPU’d onto the back of an eastbound coal load as it moves ahead to the east end of Glenwood yard (9/01/2008).

(I actually modeled this unit in HO.)

UP 6204 Former No. 157, now UP 6204, at Glenwood yard, also on September 1st, 2008.
UP 6170 Former No. 353, now UP 6170, running third on the Denver-to-Roper manifest freight on 12/06/2008.
KONICA MINOLTA DIGITAL CAMERA Former No. 276, now UP 6373, is the rear remote on a westbound load near Delta (Roubideau siding).  It was the evening of April 15, 2010 and the North Fork was still a busy branch line.
ex-sp165 Former No. 165, now UP 6211, in Glenwood Springs on 7/29/2011. I had overlooked this photo– sorry about the delay in sharing! Unit renumbered in August 2004.  Note the yellow sill stripe.
up6417 Former No. 371, now patched to UP 6417, is flying west near Deming with a heavy freight; it’s running second. Changes, other than the patch, seem to be limited to the yellow Scotchlite stripe and a replaced battery box door. Not a bad photo considering I was going about 80 MPH at the time!  (10/14/2013)

Unit renumbered in January 2002.

Back to Table
UP6337_nee_SP292 Former No. 292, now in full UP camo as No. 6337 but in its usual haunts on 4/12/2014.  Here it’s leading an eastbound coal load out of tunnel 21 west of Denver. This is a nice big image for your enjoyment!  Note the graffiti on the nose.

Repainted September 2003.

UP6216neeSP303 Former No. 303, working in a mid-train DPU set eastbound between tunnels 21 and 20. (4/12/2014)

Patched to UP 6216 in October 2007.

UP6357neeSP304 Former SP No. 304, a full repaint to UP 6357, is the trailing unit on a westbound coal empty coming out of tunnel 19 on 4/12/2014. Note the complex array of antennae on the roof.
UP6279neeSP248 Former No. 248, trailing unit on an eastbound load preparing to leave Grand Junction on 4/28/2014.

Patched as UP 6279 in June 2006.

SP177_Denver_2014 No. 177, one of perhaps a dozen units remaining unpatched as of December 2014.  I spotted it buried deep in the service tracks at Denver on 12/16/2014 at maximum telephoto. This is one of the non-DPU-equipped units (not a leader, in other words).  It does have the mandated yellow sill stripe of Scotchlite now, of course.  This is the last un-patched unit I caught.
UP6307 nee SP262 Former No. 262, showing off the typical appearance as these units near their 20th birthday: red paint faded pink, nearly to white; yellow Scotchlite sill stripes; patched; grimy and oxidized. What is unusual here is that the locomotive is running on a BNSF freight, rolling through Las Cruces, NM with a long southbound string of autoracks.  (4/05/2015)This likely will be my last shot of an SP AC4400 still in original paint.

This is my second encounter with this particular unit– see the table for a link to its appearance before being patched.

UP6233_neeSP189-2018-02-18  No. 6233 on an eastbound coal load at West Portal on 2/18/2018. Originally SP 189, delivered May 1995, and lacks DPU controls.
Renumbered March 2004, though I guess it was only a patch at that time (this paint job looks far too fresh to be that old).
UP6197_2019 No. 6197, former SP 373, is seen at Shawmut, AZ on 9/12/2019. It got this number in February 2008, possibly a full repaint then considering its flag scheme.
UP6288_2019 UP 6288, former SP 238, at Shawmut, AZ on 9/19/2019. Repainted in March 2004. It’s in disguise and running on this former SP line, somehow fitting.

Table of units

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