Fed up with the quote editor tonight, so snipped out:
Then what happened with UP’s SD70Ms? The first unit with flared radiators, 4710, was built in January 2002. The previous unit, 4709, built in August 2001 lacked them.
Without checking, I think the only SD70MACs built after 1/1/2002 were CSX and ARR units that had the flared radiators. I think this was for emissions compliance and suspect EMD used the uprated 16-710G3 also used in the SD75 series on these later units.
I’m pretty sure the “e” refers to Mitsubishi inverters…
It is the main difference between the SD70ACe and the SD70M-2…
But in Australian built export units
GT42CU-AC have Siemens equipment and GT42CU-ACe have Mitsubishi equipment.
They all have the same traction motors, Siemens design built by EMD.
The later larger GT46C ACe all have Mitsubishi equipment.
All of these units have an inverter per truck.
So “e” means Mitsubishi Inverters…
(officially, “e” means “enhanced” but only units with Mitsubishi inverters have the “e”)
Thanks, M636C. I had always assumed it meant ‘environmental’ but that makes a whole lot more sense. Thanks!
There’s a caveat to 1993-2001 ‘line haul’ locomotive emission compliance.
From the EPA-
*Locomotive models that were originally manufactured in model years 1993-2001, but were not originally equipped with a seperate coolant system for intake air are subject to Tier 0 rather than Tier 1 standards.
While EPA states for line haul 1993-2004 is Tier 1, (most) UP SD70M were Tier 0 using jacket water aftercooling through 2001.
UP SD70M 4635-4639 are actually Tier 1 built before 2002, explained in this link:
http://utahrails.net/up-diesel-roster/up-diesel-roster-52.php
Strange, but that makes sense. I wonder why the EPA set it up that way.
I think it’s the way the Government worded it. Change the grammar a bit to reflect that the engines built WITH the cooling enhancements are made subject to Tier 1 criteria, because more capable of achieving it than engines without them, and it makes full sense. (At least it does to me.)
Time for an update as it appears that the SD70MAC rebuild program is continuing at Progress Rail Tacoma. Recent arrivals include BNSF 9749, 9750, 9752, 9753 and 9769. The process seems to have been streamlined somewhat in that one unit has already had its paint stripped from the hood and is receiving the new inverters. The first batch didn’t receive new paint until they were ready to be rolled out.
There appears to be more units inside also, as 4 primer mover hood sections were spotted out in the back lot yesterday. This brings up a couple of questions. With that many hoods removed, is that part of the process to access the control systems or are they doing an overhaul of the prime mover at this time? Which brings up the next question. How does BNSF determine which units are getting the upgrade? Are these units that have been already had their prime mover overhauled and have been deemed mechanically sound or are they the ones with the fewest issues? BNSF seems to proud of them as I’ve seen recent photos of them paired up leading freights. Or is this just a case of a kid with a new toy?
At some point in the production of SD70MAC locomotives the Diesel Engine switched from a 710G3B-EC engine to a 710G3B-ES engine. One of the notes in my EMD SD70MAC shop manual says that locomotives equipped with the early EC series engine has two water pumps, one supplies water to each bank of cylinders of the diesel. The newer ES version also has two water pumps, but one pumps water to both banks of the diesel, while the other pumps water to the turbocharger aftercooler. And the plumbing arrangement is very different. I suspect that only SD70MACs with the ES engines are being upgraded. It is also being reported that they are officially being rated at 3999 hp. to keep them out of the mainline freight pool.
Interesting. I wonder why that is, as they mainline service is just about the only role they will be good at?
Rebuilt 9748 on a grain train:
Perhaps 3,999 gets them out of the most demanding coal service, leaving them other mainline assignments like this pictured grain train?
I think it’s under 3,000 hp that makes a BNSF locomotive dedicated for local services (Some SD40-2’s for instance are down as having 2,999 hp just to keep them out of the mainline pool). So this is still 1,000 too much even if it made sense to be used in such service.
Is this a paper change like I just mentioned with SD40-2’s? Or has it actually been derated 300 hp, which is what hundreds of early SD70MAC’s were delivered at?
BNSF has plenty of far better local power. It seems that effectively new high-horsepower ACs would be better in bulk service than any other role, but there are probably good reasons for the change. I’d like to know them.
Although, here’s one as a one-unit-wonder on a local:
http://www.railpictures.net/photo/578265/
[:S]
What you’re describing is SLAC or by other companies terminilogy SCAC. Seperate Circuit Aftercooling. This became utilized for Tier 1 emissions in order to lower the intake air temperature, lower NOx levels; but resulted in higher engine performance, and lower fuel consumption.
Many on here are familiar with the use of aftercooling, however for others, typically an aftercooler will use a water connection with the radiator water, this is ‘JWAC’ Jacket Water After Cooling. For ‘SLAC’ by giving the aftercooler its own water pump and radiator section, the aftercooler temperature rises at its own rate rather than engine temperature and above, allowing higher amounts of heat absorbtion.
When those production changes were made on the SD70MAC, for JWAC/SLAC was covered in a previous post in this thread.
I though the “e” stood for: electrical enhancements
More news out of Progress Rail Tacoma regarding the BNSF SD70MAC upgrades. Although I wasn’t witness to the beginning of the first units receiving their upgrades it’s certain the latest units are getting a complete overhaul. They have had their prime movers, alternators, radiators, turbos, air compressors, inverters, air reserviors and air intakes removed. Not much remaining above the frame except the cab and the radiator hood. More units have been added to the stable so it appears that BNSF/Progress Rail has decided to go ahead with this full bore. The latest units to arrive are 9729, 9768, 9771 and 9772 which brings it to about 20 units that have either been completed or in progress.
As an added twist there has been one other recent arrival that might spark some interest. Sitting with the SD70MA0C’s is BNSF 200, the first of the BNSF SD75M’s. One can only assume BNSF/Progress Rail plans on doing something with these. It remains to be seen whether they will be overhauled as is or be converted to SD70/75MACe’s. Between the SD7M/SD75I’s BNSF has probably about 90 of these in storage accounting for those that went to NS.
All the surviving units of Santa Fe’s first order for SD75Ms (ATSF 200 - 250 later BNSF 8200 - 8250) have gone to Progress Rail. Progress Rail will sell or lease them to whom ever needs them, BNSF no longer needs them.
Curious to know if BNSF owned the SD75M/I units or if they were leased? Back in 2013 BNSF sent a bunch of these to NRE but since then a good number of those have shown up in storage in BNSF yards (mainly Galesburg and Minneapolis). All of these have all their BNSF markings with the BNSF 200 series numbers.
Also, it appears that Progress Rail has intentions of doing a more than a one unit rebuild as 3 more SD75M’s have arrived in the past week (BNSF 201, 202 and 204). With the ongoing rebuild of the SD70MAC’s, the AC44C4M program, and obtaining mostly new AC power (ET/ES44C4’s) BNSF seems to have made a strong commitment to AC power. Could it be in the cards to have Progress Rail rebuild the SD75M/I’s to SD70MACe’s for BNSF?
New to this site and the forums here. I am doing so research on the SD70MAC series of locomotives and was curious if there have been updates, insight, information on the BNSF rebuild program since last year (July 2016 post).
Specifically i am curious if anyone has update or confirmation that the program did focus on those ES units and not the EC older units. I think the EC units were 1994-96 vintage and ES 1997+ vintage.
Are there other threads you all have written participated in which covers the SD70MAC’s?
thanks.
NorthEast, if you go to
and search on SD70MACe you should bring up quite a few photos of SD70MACe units.
Some of the captions on the photos list the original number of the rebuilt locomotive, so from that information you may be able to back in to which series have been getting rebuilt.
Your post prompted me to do a little research on my own as I had a window seat to the SD70MACe conversions at Progress Rail Tacoma.
First a little history. These conversions where done in two batches with decided differences on how they were done. The first batch consisted of 12 units with 2 from Build Order Number 946585 and 10 from Build Order Number 956615. The second batch consisted of 9 units from build Order Number 956615 all being delivered between June 95 to June 96. These were equipped with the 16-710G3B Prime Mover, the 16-710G3B-EC came out in Mar 97.
From outward appearances, the first 12 received Inverter upgrades, new electronics, a fresh H3 Livery and possibly some other internal upgrades. The second batch was more intense as they were stripped down to the frame except for the cab and had all the machinery overhauled. It also appears they received new or rebuilt trucks. Just my personal opinion, but it seems they were building a process as these rebuilds progressed.
The upgrades ended at 21 units and to my knowledge none have been done at any other location. Most of them seem to have been returned to primarily coal service. It’s my opinion these were a test batch and are being evaluated to see how they perform. If successful this could mean that BNSF has the choice of rebuilding their current inventory of SD70MAC’s over purchas