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:
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/
A few more SD70MACe units - 9728 coupled with 9717, and 9738, and 9748 again:
http://www.railpictures.net/photo/583129/
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.
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.
Ignoring the question on sourcing for G3B v. G3B-EC v. G3B-ES. Presumably, BNSF and EMD chose the units they chose based on a combination of leasing/ownership status and cost and value. What, other than updated inverters has changed in the units? Is it possible that given the requirements for such a major rebuild, it was more cost effective to use the older units?
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.
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Which road numbers have been rebuilt so far.
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Are the units that are rebuilt being given a new designation or are they keeping the SD70MAC name?
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.)
I have the Clyde Engineering GT-46C as being fitted with the 16-710G3B-ES engine. These were built in late 1996 and entered service in 1997. I was able to visit the assembly line in the locomotive depot in Forrestfield Western Australia and was given some documents indicating the locomotive specufication.
So I expect that EMD would have used the G3B-ES engine also from about the end of 1996.
Peter