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/
beaulieu 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.
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.
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.
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.
SooBoy61 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
www.railpictures.net
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 purchasing new as their current roster reaches the end of their service life. No program to rebuild those delivered after 6/97 with the 16-710G3B-EC prime mover has been started yet but they are just reaching the 20-year mark. Just a sidebar here, but it seems BNSF has a good number of units with that prime mover in storage.
Thaks for the research and confirmation, my findings are similar with one EXCEPTION. From earlier posts i beleive the first 200 built SD70MAC had the "EC" version of the Cooling system, two water pumps, one for each bank of the Prime Mover, which was then revised to two water pumps, one for the Prime Mover and one for the Aftercooler which improved performance and emission. so the early 1995-1996 delivered units i think are EC, there after 1997 are the ES which are the ones that went through the rebuild program. And others have said on this string that makes sense as they are more desirable. If anyone can confirm this thank you.
So exactly how many SD70MACS is BNSF rebuilding and when do they return to the rails?
Not MACs but SD75s:
http://www.railpictures.net/photo/630144/
NorthEast Thaks for the research and confirmation, my findings are similar with one EXCEPTION. From earlier posts i beleive the first 200 built SD70MAC had the "EC" version of the Cooling system, two water pumps, one for each bank of the Prime Mover, which was then revised to two water pumps, one for the Prime Mover and one for the Aftercooler which improved performance and emission. so the early 1995-1996 delivered units i think are EC, there after 1997 are the ES which are the ones that went through the rebuild program. And others have said on this string that makes sense as they are more desirable. If anyone can confirm this thank you.
Re read my posts in this thread and it explains in the simplist terms the changes in the MAC's. The difference between EC and ES both are EUI engines, EC is jacket water aftercooled. ES is EUI and SLAC.
Thanks for the input but I will have to disagree with you in this case. The first 400 or so BN/BNSF units delivered between 11/93 to 3/97 (9400-9837) were equipped with the 16-710G3B prime mover. Those delivered after that (8800-8989, 9838-9999) were with the 16-710G3B-EC. The 16-710G3B-ES was built for export models (Australia) .
Oddly, from the information I have, most of the units with the EC version are in storage. Most of the SD70MAC's in use today are with the original G3B version and were from this group the SD70MACe's were rebuilt. Does anybody have any insight as to why BNSF chose this route? Is the G3B a better candidate for rebuild or is it simply they haven't got around to rebuilding the EC units yet?
A few SD70MACe units - 9749, 9771, 9748 and 9746:
http://www.railpictures.net/photo/622827/
http://www.railpictures.net/photo/609318/
http://www.railpictures.net/photo/596882/
http://www.railpictures.net/photo/595490/
A few more SD70MACe units - 9728 coupled with 9717, and 9738, and 9748 again:
http://www.railpictures.net/photo/583129/
http://www.railpictures.net/photo/590445/
http://www.railpictures.net/photo/582112/
Looks like Progress Rail/BNSF is going ahead with a full rebuild of the BNSF SD75M/I units. Recent photos show most of the remaining units at Progress Rail Mayfield, KY facility except for a couple that remain in Tacoma, WA. I also noticed that the newly rebuilt ones are sporting the new H4 livery. Wonder how the black will hold up over time?
I wonder if any will keep thier excecutive colors?
I doubt it, all the recent rebuilds have come out with the latest livery. It would be nice to see BNSF have some units in heritage colors like UP amd NS though.
SooBoy61 Thanks for the input but I will have to disagree with you in this case. The first 400 or so BN/BNSF units delivered between 11/93 to 3/97 (9400-9837) were equipped with the 16-710G3B prime mover. Those delivered after that (8800-8989, 9838-9999) were with the 16-710G3B-EC. The 16-710G3B-ES was built for export models (Australia) . Oddly, from the information I have, most of the units with the EC version are in storage. Most of the SD70MAC's in use today are with the original G3B version and were from this group the SD70MACe's were rebuilt. Does anybody have any insight as to why BNSF chose this route? Is the G3B a better candidate for rebuild or is it simply they haven't got around to rebuilding the EC units yet?
No you're wrong; they switched to 16-710G3B-ES 1/1/1996, already covered this. The ES engine no doubt was used in Australia but was not unique to there.
The EC engines were used 9400-9716, have shown to be less desirable, have more hours more chances of being bad order, it would be expensive to convert them to SLAC (Most of the reason) . However two MACe's do use an EC engine, I believe this is most likely to compile fuel economy data, maybe they will see from data it's worth to upgrade the earlier units.
So, the initial BN order delivered prior to 1996 would all be 16-710G3B Then some number post 1/1/1996 were 16-710G3B-ES @4200HP, then they switched back to the 710G3B-EC @4000?
Is it possible to get a break down by unit number?
Rather curious to see your source of information on the use of 16-710G3B-ES engines in BNSF SD70MAC units. All my sources show the -ES version didn't come out until 2003.
Are you using Wikipedia? it's wrong.
9400-9716 had 16-710G3B-EC
9717-8800 had 16-710G3B-ES
8800-9999 had 16-710G3C-ES
9400-9716 Some are MUI the later ones are EUI.
I have EMD/BNSF Order #936445 5/24/1995 which lists ENGINE as 16-710G3B-EC covering (63) SD70MAC which were delivered in 1995 road numbers 9475-9499; 9504-9541. It is not the complete specification, an interim summary, as this was part of the original order by BNSF of 300 or so, the first order of SD70MAC by any railroad. Seems to confirm above to some degree, that EC were first units delivered, then replaced by ES, at least domestic deliveries. Is not the major difference of EC to ES that the EC had a dual but shared cooling system and the ES migrated to dual dedicated water pump and cooling arrangement, one for engine and the other for aftercooler, as discussed long ago on this thread? And the EC being a dual shared system, being less desirable as it is a lesser performer and difficult to retrofit? thanks.
Another factor in selecting units for upgrade, not all MAC's have isolated cabs. It appears 9572 is the first isolated cab SD70MAC. Safe assumption the units 9400-9571 will not be upgraded, looks like they're laid up as of July, possibly "surge fleet".
In 1995 Isolated Cab and Electronic Unit Injectors was all new technology, Burlington Northern wanted these implemented, that's why they were phased in.
A few questions.
1. Which road numbers have been rebuilt so far.
2. Are the units that are rebuilt being given a new designation or are they keeping the SD70MAC name?
Entropy Are you using Wikipedia? it's wrong. 9400-9716 had 16-710G3B-EC 9717-8800 had 16-710G3B-ES 8800-9999 had 16-710G3C-ES 9400-9716 Some are MUI the later ones are EUI.
I have no doubt that Wikipedia contains errors, I'm trying to jive a delivery date of early 1993 for the demo units, late 93 for the first of the 300 with a supposed intro date for the EC of 1995.
Are you then saying that the EC version of the 710 came out in 1993?
Actually, the flawed Wikipedia table actually implies this, because the 12-710G3C-EC in the F59PHI is dated as 1993. So clearly EC was available. (ugh,Someone has modified the table since our discussion in the SD90 thread some time back. All the engines are listed as 900RPM, but that is NOT true and not what it used to say.)
SooBoy61 Rather curious to see your source of information on the use of 16-710G3B-ES engines in BNSF SD70MAC units. All my sources show the -ES version didn't come out until 2003.
Our community is FREE to join. To participate you must either login or register for an account.