Monday, August 18, 2014

War Stories - Episode 26: EMD's travelling MAC show

This is my favorite war story.

It has the happiest ending, I think - at least in my own mind.

It involves the assent of AC propulsion locomotives.  It was real, tangible progress and I played a small part.

I still have a copy of the test report I wrote following the test, so my memory is "enhanced"!

The equipment needed to make a North American AC propulsion freight locomotive started to seem technically practical back in the late 1980s.  Amtrak and CP both took some "off the shelf" European equipment and retrofitted an existing locomotive to get an idea of how it might work out.  Neither retrofit was particularly successful except as a proof of concept to show that the high-power electronic switches that could chop DC power back into AC in a high horsepower diesel locomotive.

The next step was to see if a modern, state of the art new locomotive could be constructed.  The locomotive builders were reluctant to build a demonstrator fleet since the cost of development was so high and they were uncertain of follow-on orders even if it was wildly successful.  Without a demonstrator, no railroad wanted to take the first leap.  Too many things could go too badly to justify such a huge investment.  Things were at an impasse.

Out of this, the AAR formed an ad-hoc committee to explore funding a joint AC demonstrator fleet.  The ad-hoc committee's charge was to develope a specification and test plan for a demonstrator fleet.  It was championed was Steve Cavanaugh of CP.  Mike Iden of the CNW (and later UP) was on the committee, too.  Some pretty high priced talent.  Then there was little, old me.  I was selected to represent Conrail on the committee.  It got rolling in 1991 and involved discussions with locomotive builders - big and small, propulsion equipment suppliers - Siemens, ABB, et. al., one person from each of the major US and Canadian roads - Conrail, BN, ATSF, NS, CSX, CN and CP, and a few folk from the AAR staff.

Work progressed fairly quickly and the committee settled on a specification for a 5000-6000 HP six axle locomotive.  The thought was it could replace SD40-2s on a 3 to 5 basis in drag service and nearly that in merchandise and intermodal service as well.  A fleet of roughly 25 was proposed so that it would spread the development costs out and garner enough experience to understand how well AC propulsion worked and what remaining work needed to be done in order to have a reliable fleet.

Some interesting rememberances from the meetings...

Republic Locomotive came in one time expressing interest.  The owner wore a cowboy hat and flew his own plane up to Chicago from Spartanburg, South Carolina.  A strange outfit run by interesting guy - or an interesting outfit run by a strange guy?  It was hard to tell.

At another meeting, the NS representative was fully on board with the work we were doing, offering several helpful suggestions.  At the next meeting, he stated NS had no interest in participating and he was only there to keep an eye on what the industry was doing.  He sat silently through the whole meeting.  I guess he got a dose of "we ain't doing it and keep your mouth shut" when he got home.  NS tended to be that way, culturally.

We were just at the point where we needed the railroads to start to ante up for the test fleet when the whole project collapsed on a stunning announcement.  BN had just placed and order for 350 AC locomotives!  A mammoth bet that obviated the need for a test fleet.

No more fun meetings to go to.  Rats!

During the time the committee met, EMD and Seimens constructed four demonstrator locomotives.  They were based on the current production DC locomotive, the SD60M, but would have AC propulsion.  They were christened SD60MACs and spent the first part of their life on the BN testing prior to production.

Once the testing was done and production on the first of the 350 was underway, EMD made three of the demo units available for other roads to test.  We were scheduled to get them in August of 1993.  I was all over it!

Unfortunately, the transportation department had decided they were just going to run them all over the network on all kinds of trains.  They even had a list published.  It was not good.  It wouldn't tell us anything about the limits of the AC propulsion system.

What we needed to do was give that AC propulsion system a workout.  Get them "on their knees" at close to those adhesion levels EMD was claiming.  We already knew what a 3800 HP six axle could do on an intermodal train.  The SD60MAC would perform identically.  But, could it pull with 130,000+ lbs force? THAT was the question we needed the answer to.

They had EMD's radial truck which helped them to keep a good grip in curves.  We were familiar with these, having tested some SD70Ms a couple years ago.  What we really want to see was those crazy, high adhesion levels.

Testing radial trucks against four axles on Elsworth Secondary

We argued, through the right channels, of course,  for a test plan that would have it work on the Boston Line, Pittsburgh Line and West Virginia Secondary with some tonnage trains.  It was accepted!  I was the guy who had to coordinate the test. It was probably the biggest, most complicated task I'd been handed since my time at Conrail began.  I lobbied hard to get it.

Time to get to work!

The locomotives would need cab signal installed.  We arranged for one unit, BN 9503, to be done at Enola.  A quick calculation showed that the AC propulsion system would be running at roughly 100 Hz at 70 mph.  Uh, oh.  That's the same frequency as the cab signal system carrier.  We'll need a test to make sure the two systems don't interfere.  EMD designed and installed some special shields to go around the receiver bars to reduce interference.

We involved Harmon Electronics, our current cab signal supplier, our C&S department - they were also concerned about interference with overlay circuits for grade crossings -  and EMD.  I arranged a special test trip from Enola to Thompsontown and back on August 17, 1993 with special permission to operate at 70 mph.  There were folk at road crossings along the way and Harmon was measuring the raw signal coming in off the receiver bars behind the front pilot.

The whole thing came off without a hitch.  Harmon's data showed input from the propulsion system, but it was faint, less than 20% of the track circuit signal. We might have been able to get away without the shields, but things worked well with them.  That was a job for another day.  We were ready to go!

This is the only picture I can find of the test consist.

Here's the test routes as executed:

8/24/93 UBO coal train Conway PA to West Springfield MA *
8/25/93 BAL ballast train to Selkirk NY
8/26/93 SEAL merchandise train to Allentown PA
8/27/93 lite to Enola PA
8/27/93 ENPI merchandise train to Conway PA
8/28/93 lite to West Brownsville PA
8/28/93 ULK coal train to Enola PA *
8/29/93 ZSR ore train to Pittsburgh PA *
8/30/93 lite to West Brownsville PA
8/30/93 UFY coal train to Enola PA *
9/1/13 ENPI merchandise train to Conway PA
9/1/13 XCG empty hopper train to Dickinson WV
9/3/13 UGS loaded coal train to East St. Louis *

* trains that tested adhesion close to design limit

One of the things we had to watch was drawbar strength.  If you had standard C couplers and all three AC units on line, you could very easily break a knuckle, regardless of train weight.  E couplers could withstand whatever all three units could put out.  We had a rather detailed test plan, complete with how many units could be on line with what kind of train, what data to collect from EMD's test car, and a schedule of trains, routes, and riders. Testing was underway.

Some testing stories:

While making the westbound trip on the Pittsburgh Lline with the ZSR ore train, somewhere somebody in transportation got it in their head that we might be able to do away with helpers if we used AC locomotives. That could be true under the right circumstances, but not on the day they wanted to try it.  It was a 11,100 ton ore train with grade C couplers.  All three units on line.  Heading over Horseshoe Curve.  Quick calculation.  1.8% grade x 20 #/ton x 11,100 tons = 400,000# force!  Three SD60MACs should be able to come close, but Grade C couplers are only good for 250,000# - might take 300,000# in a pinch if you aren't too far into the fatigue life already.  We called the division, "Don't try it.  You'll get a knuckle for sure." "We want to try it, just to see..."  "Don't do it.  It won't work."  Fell on deaf ears.  Up the hill went the ore train. The train was just getting into the meat of the grade when....BANG went a knuckle about 6 deep and WHOOSH went the air.  Got the train back together and called for helpers and off they went.  Didn't try that again.

We did get to work all three units hard with some coal unit trains with grade E couplers.  At least one was on the West Virginia Secondary and one was up the west slope of the Pittsburgh Line.  In both cases, the results generally successful, but not 100% so.

The one on the West Virginia Secondary got a knuckle after encountering a thunderstorm downpower.   After getting the train back together, it had great difficulty getting up to 5 mph, however once over that, the units dug in and accelerated the train.

The other was from UFY coal train to Enola with a 110 car coal train.  I happened to be riding this one but almost missed out.

Just before it was my turn to accompany a test run, I wound up with a ridiculous, never-had-one-like-this-before, headache.  My doctor's best guess was viral meningitis.  I have no idea if it was or wasn't, but it was bad enough to keep me from getting much sleep or doing anything except lying in bed with my eyes shut. Ugh.  He gave me some percocet to zonk me out.  Didn't make a dent.  The good news was the headache pretty much faded into a dull ache after a couple days regardless of the percocet.  I finally got a good night's sleep and the next day headed out to West Brownsville to catch up with the test consist.

The test consist included the three SD60MACs, EMD's test car, and 110, 100 ton hoppers.   Trailing tonnage was 14,700 tons.  The destination was Enola where these 110 car trains were chopped down to 90 car trains in order to operated south through the B&P tunnel to power plants in Maryland.  The train was right at the limit for tonnage on the west slope, so we had a pair of helpers tacked on the rear at Conemaugh for safety.  Started to pull.  Not moving.  Dynamometer couler in EMD's test car was showing less 100,000# per unit with quite a bit of variability.  Lead unit is jumping up and down a bit.  EMD advises the engineer to trust the wheel creep system and just keep pulling.  Slowly, we start to move.  After 12 minutes, we're only a few hundred feet down the track.  Still not pulling anywhere close to 35% adhesion.

We call for the helper to give a nudge. He shoves and we start moving for real.  Once the speed got close to 3 mph, the AC units get a grip and we start making a solid, steady 135,000# a unit.   We have the helper throttle back.  The train moves fairly smartly away from Johnstown and shortly into the meat of the west slope a steady 1.1% grade with a stretch of 1.25%.  We hit it in notch 8, making 8 - 10 mph all the way.  Not a hitch the whole way up.  If these had been DC SD60s, they'd have burned their traction motors to a crisp  These AC locomotives were the real deal!

The trip down the Horseshoe Curve and along the Juniata River valley to Enola was uneventful.  I remember the rather strident tone of the BN horn.  It was more piercing and strident than the Conrail standard three note Leslie.  I also remember the cloud of black blowing from the hoppers as we rolled along at 40 mph.

Soon, the testing was over.  The cab signal system was removed and the locomotives moved on to the next railroad to test.  I was left with a small mountain of chart recorder data to analyze and a report to write.

There were two big questions:

1. Was the 32% adhesion real?

2. Where and how could or should we use AC locomotives?

The test answered the first question.  Yes.  32% adhesion was real.  Again and again the locomotives achieved 32% or better adhesion.  The only fly in the ointment was the two times at very low speed when the locomotives couldn't get a grip.  Any purchase of AC locomotives would have to be contingent on this flaw being resolved.

Where would we use them?  That was a tougher question.  We looked at three cases.  A 4000 HP version for drag freight, a 5000-6000 HP version for Merchandise and Intermodal and in locations where helpers might be eliminated - or some combo of these.

As it turns out, the best case was for the 5000-6000 HP locomotive operating on the Pittsburgh Line with merchandise and unit coal traffic.  Taking a sample of actual trains, we calculated what DC and what AC power they would require and then aggregated to get a replacement ratio.  They also showed a decent replacement ratio for general freight service on the Chicago Line, but that service didn't take advantage of the high adhesion.  I had the report completed by the end of September 1993.

The report made four specific recommendations:

  1. Use any 4000 HP AC locomotives in drag service only
  2. Pursue a 5000-6000 HP AC locomotive in lieu of a 4000 HP AC locomotive
  3. Perform comprehensive testing of any and all AC locomotives to insure no interference with cab and wayside signalling using audio frequency carriers
  4. Pursue integrated distributed power system (Harris Locotrol with EPIC airbrakes to maximize locomotive utilization and minimize add-on hardware.)

The report was written just as Conrail was getting interested in some GP60s and SD70MACs for 1995 delivery (with isolated cab, of course!).  The report got a fairly wide distribuiton and I think it helped push Conrail toward changing the order to EMD SD80MAC locomotives.

There was some discussion about EMD's 6000 HP four stroke engine, however, we'd seen the havoc wrought by even small changes to proven designs.  There was no way you could convince the Mechanical Dept. to take a chance on that.

The 5000 HP 20 cylinder 710 engine was different, though.  Even though no railroad had any running around and the bitter taste of the 20-645 still lingered , there were over a hundred in marine service by 1993 and the economics around the replacement ratio didn't work for a 16-710 engined 4000 HP AC locomotive.  It helped that Conrail did have some good experience with the improved 20-645 engined SD45-2s.

The order was placed.  28 SD80MACs - and later the two demonstrator units EMD built to Conrail specs.  They were the most technologically advance locomotives in the US at that time.  The collection of features they had was unparalleled:
  • Electronic airbrake (EPIC II)
  • Electronic cab signal/LSLtrain control (Harmon Ultracab II)
  • Locotrol DPU
  • EMD ICE - integrated cab electronic and displays system
  • Isolated cab with sound proofing (Whisper Cab)
  • Electronic fuel injection (RFI)
  • Radial trucks
  • and, of course, Siemens AC propulsion
By the time they were delivered, I'd moved on to a job in the Intermodal Service Group.  They arrived in late 1996 to great fanfare at Conrail.  There's lots of good info here and here.

A of pair nearly new SD80MACs sitting in Pavonia NJ
In service, they had some teething problems, particularly around the EFI, but genearlly settled down and performed well.  Conrail did some goofy things with them, like running a few in intermodal service and eventually putting them all on the Boston Line for maintenance convenience.  This was fairly low utilization service for locomotives we should have be running their wheels off on the Pittsburgh Line.

1997 was the start of the NS/CSX merger madness and plans to purchase another big chunk of SD80MACs went by the boards.  In the end, CSX and NS split the fleet.

They are now approaching 20 years old and are still soldiering on.  NS's VP Mechanical recently said they were a good, solid locomotive.  NS keeps them captive between Altoona and Conway for maintenance familiarlity - they are unique.

Every now and then, a pair of SD80MACs leak out of Conway on a mainline train headed for Enola or points east.  Just as God intended.


  1. Great article Don. I remember those demo units, the sd80s were beauties

  2. Great article Don. I remember those demo units, the sd80s were beauties


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