Know Your Union Pacific EMD Locomotives

There's something about being able to identify a locomotive. Perhaps being able to identify something allows a person to connect with the subject. This was a big deal in the days of steam when spotting a specific engine class could tell you not only what railroad, but whether it was a brand new lighwogjtstreamliner or a thundering Pullman heavyweight behind her. Today, identifying diesel locomotives in main line service isn't always simple matter.

For a complete guide on identifying locomotives,
this is probably your best bet! Schraders / Library

On one hand, when I first started trying to figure out the make and model out on the Moffat Route and elsewhere, there were EMD locomotives and GE locomotives. I quickly figured out a fast rule of thumb: The GE's always seemed to have an exhaust on the roof, usually in the middle of the hood section. These days, the exhaust is even easier to spot. I just look for the fluted aluminum stack sticking up about a half-foot above everything else. If it's there, it's a GE loco rather than an EMD.

On the other hand, Identifying the model of a locomotive isn't as simple as a quick look. While it's relatively easy to tell the difference between a GE and an EMD locomotive, it's significantly more complex a task to determine the model.

This isn't a comprehensive guide. There are books like Greg McDonnell's 2008 guide that are much more researched. However, there is a fairly consistent means of identifying the two most popular, state-of-the-art models by EMD that are in use on the Union Pacific railroad (as well as BNSF). It involves examining the radiators.

Click to enlarge. Photo collage by Alan Radecki (CC 2.5), Identification and graphics by Colorado Railroads

As you can see, the three different versions on top are all considered SD70Ms, and the fourth is the Tier 4 compliant SD70ACe. The 3 bottom locomotives all have flared radiators, but only the ACe's have space between the radiators and the end of the hood.

As late as 2004, EMD produced the previous version of the SD70s AC version, the SD70MAC, which might better explain the disparity in suffixes of the EMD model numbers.

Deciphering the EMD Model Numbers

SD stands for Special Duty because it was anticipated that this design would see only limited use as opposed to General Purpose (GP) road switchers. While GP locomotives have 4 axles, SD series have 6 axles, 3 per truck, with each axle powered independently. The notation for this by AAR standards is C-C. As far as it being Special Duty, EMD no longer produces any of the GP series.

70 indicates the place in the series. As a rule, EMD numbered SD series on the 5s, but skipping 55 and 65. Since SD70, EMD filled SD75 and then SD80 and SD90 series in short succession, but the latter 2 were non-starters with design shortfalls. The SD70, like the SD40, has built a reputation for reliability.

M was applied as a suffix applied to comfort or safety cabs when they were the option and not standard. When the SD70M was introduced, the standard cab was the short hood, low nose design from the early days of EMD locomotives. Today, the situation is reversed, with any company that wants one to specify the Spartan cab. So far, the Spartan has but few takers.

AC Initially, all diesel electrics functioned using Direct Current (DC) produced by a prime mover as two phase AC and then rectified to DC. Today's AC units change that DC electricity to three-phase AC. This solves some problems that have dogged DC diesel-electrics for years.

e eco-system friendly, specifically "EPA Tier-3 emissions certified" as EMD says on their site.

One last thing...

Incidentally, I've appreciated Union Pacific's long-standing choice of the American flag for the side of it's locomotives. Sure, it's not a big leap from the UP shield to the flag, but being an American (and especially a Coloradoan) is particularly important to me.◊

POTD: Ah, Springtime In Palmer Lake!

Exactly what season it is might fool many a viewer but not locals and certainly not Joe Blackwell. He caught this BNSF southbound coal drag behind SD70MAC #9719 coming through Palmer Lake after the storm in the background left more than a little hail behind.
Photo Joe Blackwell

Today's POTD is a set of coming-and-going photos by Palmer Lake's Joe Blackwell. The recent spate of hailstorms that have rushed northward along Front Range has not passed unnoticed by railroad photographers. The juxtaposition of winter white from storms whose winds "shake the darling buds of May" with their bright green leaves seems irresistible to the shutterbug.

It's the same train, same vantage point, but a completely different perspective! BNSF SD70MAC #9767, from the same order as the lead unit, trails a pumpkin in almost mirror fashion of the other end of the train. The same cannot be said of the skies.
Photo: Joe Blackwell

Of particular interest is the contrast between the skies of the two photographs. This is no trick. The storm and the innocent-looking cotton puffs are indeed in the same sky. The only difference is the angle and the time it took for the length of the train to pass. It's just a hint of the volatile nature of springtime in the Rockies.◊

POTD: BNSF Hiring Pony Power

Norfolk Southern 2728, an SD70M-2, leads sister 6941, an SD60E downgrade from Palmer Lake, CO with a southbound BNSF manifest. BNSFs lack of power to match traffic levels has led to some unusual colors on point.
Photo: Joe Blackwell

Photographers love a power shortage when it means rare locomotives! Sunday's Photo of the Day contained one of Norfolk Southern's heritage units, and today's likewise features some pony power, but no heritage units unless you count Cascade green of Burlington Northern, which grows rarer by the year. Joe Blackwell, no stranger to POTD, captured the rare power near Monument in April this year as the BNSF manifest continued downgrade from Palmer Lake on the Pikes Peak Sub. He also has caught CSX power on point near the same location.◊

POTD: Two Rocky Mountain Favorites Far From Home

How do you follow the greatness of the last three POTDs by Mike Danneman? It's not impossible, but highly improbable. Yet I can't help but go for a great night shot. I have truly enjoyed rail photography's love affair with night-time exposures. The 24-7-365 nature of railroading and the natural absence of light makes for time exposures that highlight what would be missed and hide what would be obvious from a similar exposure taken in the daytime.

The Folsom local lights up the night in Sacramento, California as it makes its scheduled pick-ups and
drop-offs, far from the Rocky Mountains UP 1901/(ex-D&RGW 3155) called home in its early years.
Photo: Joe M

California photographer Joe M. published this photograph on his RRPictureArchives.net site in 2009. His one photo that qualifies for inclusion as POTD is Union Pacific 1901, last seen here on Tuesday when she was with her two sisters. Today, we have the former Rio Grande GP60 waiting while she takes her conductor back on board. Tools like the trusty lantern of the conductor are as old as railroading itself. A lantern serves to light the right-of-way, as it does here, as well as inspect cars and signal to the rest of his team how they should proceed. It's a long night in Sacramento, California, longer still if you dream about enjoying a cold one after your shift is done.◊

POTD: 3 In A Row - The Rio Grande GP60's

In his second appearance this week for POTD, Mike Danneman is an accomplished railroad photographer whose work shows up in books and Trains magazine with enough regularity that many photographers might envy him. Of course, he has a way of being in the right place at the right time!

GP60s 3156, 3154, & 3155 lead SP and UP locomotives head north toward Blue Mountain Crossing
between the Big Ten curves and Tunnel 1 west of Denver on its way to Salt Lake City, Utah.
Photo: Mike Danneman

As an example, he captured today's Photo of the Day in the foothills west of Denver as the three GP60s of the Rio Grande--the last locomotive units ever--hauled the Denver to Roper (Salt Lake City) manifest train up the grade toward the Moffat Tunnel on the old Denver & Salt Lake. In an interesting twist, it would seem a the six locomotives formed a recapitulation of 60 years (roughly) of the Rio Grande's ownership history with itself, Southern Pacific and Union Pacific. Regrettably, all three locomotives have been repainted or renumbered, per Utah Rails, but all are still active within the last year.

There is no doubt that it's a late 90s Denver skyline, is there?◊

POTD: St. Patrick's Day Green Cruises By On The Moffat Road

BN and March 17th seem to go together, don't you think? In this case, Mike Danneman captured a surviving BN locomotive in Cascade Green on the long ramp of a grade toward the Flat Irons and the Moffat Tunnel. As a direct result of the UP-SP merger, BNSF obtained trackage rights over the Moffat Road and since then has sent a remarkable quantity of trains via that route.

Spartan-nosed BN 7062, an EMD SD40-2, leads it's Stockton-based consist through Rocky, passing
a Union Pacific coal drag with it's distributed power visible behind the derail stand on Oct 1 1999.
Photo: Mike Danneman

No stranger to trackage rights, BN had long enjoyed the fruits of it's agreement with the Rio Grande for a connection between Denver and it's southern Colorado assets along the Joint Line. Now with well over 15 years on the route, BNSF's colors appear to be on the Moffat to stay.◊

POTD - Grande Retirement of a Tunnel Motor

Kevin Morgan, long a favorite, gets the POTD honor today, not just because of the unique perspective
of this shot, but because he remembered the detail of staying out of the reflection of Ogden, Utah.

Since it's retirement in 2008, Rio Grande SD40T-2 #5371, the only Rio Grande diesel to retire without being re-numbered or sold off, has been joined at the old loco's home by SD40T-2 #5401, which saw brief service as patched Union Pacific 9871. Though they haven't relocated the engine to the property, it's good to know that such vital pieces of contemporary railroading is going to survive in the both of the states the Rio Grande called home.◊