Hello all .
Out of curiosity is there a virtually an unlimited number of older locos sitting in various "rotten roads" waiting for rebuild . Im just curious to know if there are plenty left .
NS still has a fair number of Dash-9's left for its ongoing AC44C6M conversion program with GE. CN appears to be in a similar situation with its Dash-9's.
I believe CN's current GE DC-to-AC order is for 50 units. This will still leave about 170 DC traction Dash-9s on our active roster. We also have nearly 400 EMDs (SD70I, SD75I, SD70M-2) which could become fodder for a AC rebuild program.
NS at one point had 130 SD70M-2s, but all were retired in recent years. A few have been overhauled by Progress Rail and re-sold to short lines but I'm not sure what became of the rest.
UP's giant fleet of DC SD70Ms is probably the biggest remaining candidate for such a program, they've already made arrangements for Wabtec to rebuild hundreds of GEs of similar age.
How many Dash-9s and SD70MACs does BNSF still have in storage?
Greetings from Alberta
-an Articulate Malcontent
NS held on to 46 of the SD70M-2's and has recently returned 30 of them to service.
Progress Rail is building two prototype SD70M-2 to AC conversions (using two of those former NS examples) that NS will be trialing. Presumably if successful, we'll see a big chunk of the survivors being rebuilt.
I note the OP mentioned Tier 2 and Tier 3.
The Dash 9 only met Tier 1 as did(I think) the later SD70s (and MACs).
The SD70ACe introduced Tier 2 as did the ES44.
So most current rebuilds will only meet Tier 1. The SD70M-2s would meet Tier 2 and could be upgraded to Tier 3. While it hasn't happened yet ES44DCs would logically be the next targets after the Dash 9s run out...
Since Dash 8s are so generally similar to Dash 9s, I'm surprised that these haven't been upgraded to near Dash 9 specifications with AC traction. The upgrade would cost more on the older locomotive. But while there are Dash 9s available, I guess that's the easiest decision.
Peter
The only real question limiting Tier 2 or Tier 3 is money, how much of the original locomotive is reused beyond the frame, trucks, and possibly the alternator.
I would argue that the former EMD SD9043MACs and the former NS SD70M-2 qould be the cheapest. As mentioned the SD70M-2s already meet Tier 2. The EMD SD9043MACs offer a frame with a lot of space and a 710G3 block that can be rebuilt though it would likely need all new power assemblies, fuel injection systems, but that is what most ECO rebuilds involve.
CPKC's SD30C-ECO and GP20C-ECO rebuilds only meet Tier 0+, but that was CP being cheap, at least they used mostly new parts unlike NS with their SD70ACU locomotives.
While this is true for Progress/EMD rebuilds, for Wabtec/GE rebuilds, if you start with a Dash 9 you are limited to Tier 1, since the FDL engine is not suitable for Tier 2, although the marine FDM was available in Tier 2 form, presumably requiring significantly more cooling.
M636C I note the OP mentioned Tier 2 and Tier 3. The Dash 9 only met Tier 1 as did(I think) the later SD70s (and MACs). The SD70ACe introduced Tier 2 as did the ES44. So most current rebuilds will only meet Tier 1. The SD70M-2s would meet Tier 2 and could be upgraded to Tier 3. While it hasn't happened yet ES44DCs would logically be the next targets after the Dash 9s run out... Since Dash 8s are so generally similar to Dash 9s, I'm surprised that these haven't been upgraded to near Dash 9 specifications with AC traction. The upgrade would cost more on the older locomotive. But while there are Dash 9s available, I guess that's the easiest decision. Peter
But then there's the AC traction package. The locomotive kept her Dash-9 trucks. No word on what mods were made for the 3rd party traction motors. But if there is an AC motor that can drop into the space of a 752 with little/no modification then the Dash-8 AC conversion becomes that much more realistic.
Editor Emeritus, This Week at Amtrak
M as we both know US domestic Dash 9s / AC4400s can take a significantly larger cooling group than the originals had so the potential for water/air intercooling improvements is huge .
I'll have to ask how the AC4400s are going in WA . I don't the think the original Dash 9s had split / seperate circuit intercooling but if the AC4400 rebuilds do I'd think that if properly tuned they could be significantly cleaner - and more fuel efficient .
BDA M as we both know US domestic Dash 9s / AC4400s can take a significantly larger cooling group than the originals had so the potential for water/air intercooling improvements is huge . I'll have to ask how the AC4400s are going in WA . I don't the think the original Dash 9s had split / seperate circuit intercooling but if the AC4400 rebuilds do I'd think that if properly tuned they could be significantly cleaner - and more fuel efficient .
I read Wabtec's press release very carefully. They claim better fuel consumption and better emissions but they don't claim that they meet Tier 2, which I'm sure they would if they met that standard. Of course, they may not have tested the AC44C6M, as opposed to the US standard AC44C6. Since there are no standards to meet in Australia, why incur the cost of testing...
Of course, with the same radiator but separate air to air intercooling, the ES44ACi meets tier 2, And maybe Tier 3 for the later units.
I don't know for sure about the intercooling in Dash 9s. I seem to recall that separate intercooling was one of the changes from the Dash 8, but that was some time ago.
To answer D.Carleton's question, I think the spanish manufacturer CAF supplied the traction motors that fitted in Dash 9 trucks. GE have basically replaced the truck frames with AC4400 trucks on most of the Dash 9 rebuilds. I'm told they modified one set of Dash 9 trucks, but these were not regarded as successful. But if you are replacing all the trucks on Dash 9s, you could also replace the trucks on a Dash 8. However, there isn't an existing design of AC truck to fit a Dash 8.
I've never seen a Dash 9 local or Erie built without the engine coolant water/air interheaters . The USD Dash 9s I worked on I believe were amongs the last built by GE prior to the Evo line .
I'd have to do some research because I think there is a difference between split cooling and seperate circuit water/air intercooling . To me it doesn't make sense to put a huge radiator on a Dash 9 or AC4400 purely for engine cooling . The roads to power and efficiency in any forced induced engine is charge temperature .
I think the Americans did entertain the idea of doing a Dash 8 AC40/4400 type conversion but the reality was that there were too many detail changes D8 to D9 .
Also I think I remember reading that the D8 frame was shorter .
In the transition from Dash 8 to Dash 9 maybe a hundred of the final Dash 8s received split core cooling. Some also came with EFI. NS' Dash 8.5 program rebuilt standard cab Dash 8s with both so adding such to a rebuild isn't out of the question. Dash 8 (six axle) frames are three feet shorter than a Dash 9. (An AC6000 is three feet longer than a Dash 9.)
A Dash 8 rode on the traditional GE truck with 40" wheels. The new 'roller-blade' trucks have 42" wheels.
And speaking of trucks, the traditional GE floating bolster truck has a bolster that fits into a traditional center pin on the locomotive frame. The newer, bolsterless trucks support the locomotive on four "loadbearers" (their term) and transfer motion via the "center pin bearing assembly," a locomotive frame mounted pin running through the truck frame to the coupler level. To add the bolsterless trucks to a Dash 8 would mean A LOT of locomotive frame modifications. Doubtful the mechanical chiefs are ready to make that level of commitment.
D.Carleton In the transition from Dash 8 to Dash 9 maybe a hundred of the final Dash 8s received split core cooling. Some also came with EFI. NS' Dash 8.5 program rebuilt standard cab Dash 8s with both so adding such to a rebuild isn't out of the question. Dash 8 (six axle) frames are three feet shorter than a Dash 9. (An AC6000 is three feet longer than a Dash 9.) A Dash 8 rode on the traditional GE truck with 40" wheels. The new 'roller-blade' trucks have 42" wheels. And speaking of trucks, the traditional GE floating bolster truck has a bolster that fits into a traditional center pin on the locomotive frame. The newer, bolsterless trucks support the locomotive on four "loadbearers" (their term) and transfer motion via the "center pin bearing assembly," a locomotive frame mounted pin running through the truck frame to the coupler level. To add the bolsterless trucks to a Dash 8 would mean A LOT of locomotive frame modifications. Doubtful the mechanical chiefs are ready to make that level of commitment.
There would be no need to replace the Dash8 trucks if motors that fitted in place of a GE 752 were used. It should be possible to cast a new truck frame that accommodated a GEB 13 but otherwise mated up to the existing Bolster, if you wanted to stay all-GE. This might also allow 42" wheels if that were important. This might cost less than providing a new AC motor compatible truck to a Dash 9.
The general layout of the Dash 8 and Dash 9 are similar, so you could fit an AC4400 air conditioner under the cab and fit the inverters in a box behind the left side of the cab.
The Dash 9 rebuilds get upgraded exchange engines anyway, and Dash 8s would need a Dash 9 radiator along with the engine and electronics upgrades on a Dash 9.
The items actually retained on a Dash 8 would be about the same as those on a Dash 9, assuming it already had a wide nose cab.
M636C There would be no need to replace the Dash8 trucks if motors that fitted in place of a GE 752 were used. It should be possible to cast a new truck frame that accommodated a GEB 13 but otherwise mated up to the existing Bolster, if you wanted to stay all-GE. This might also allow 42" wheels if that were important. This might cost less than providing a new AC motor compatible truck to a Dash 9.
The original E60C built for BM&LP came on the floating bolster truck with 42" wheels and 780 traction motors. Maybe these were special castings in deference to the larger appurtenances. I have never seen one in the flesh let alone worked on one. There is one left and may be displayed someday in Williams, Arizona.
Was there any physical difference between the C40-8W and the C41-8W or was it mainly software? I think BNSF still has a bunch stored in Galveston.
rdamon Was there any physical difference between the C40-8W and the C41-8W or was it mainly software? I think BNSF still has a bunch stored in Galveston.
I'm not sure how many Dash 8s are left over there .
Would I be right in thinking that there are plenty of Dash 9s either in service or stored . Obviously a D9 is a bit easier to package the AC upgrade .
Now to the 7FDL V16 . I did search for info about "split cooling" and it seems that GEs D9 era idea was to cycle some of the coolant through the intercoolers and I think compressor . If this is the case then it probably doesn't intercool quite as well as a seperate circuit between dedicated radiators and the intercooler heat exchangers themselves .
I think EMDs system has two engine driver water pumps , the second for the seperate circuit intercoolers . I guess it wouldn't be impossible for a Dash 9 to go seperate circuit intercooling especially if they had the larger later cooling group fitted . If the FDL couldn't drive a second pump then an electric one would work .
Where I'm going with this is possible Tier 2 emissions for US domestic use . I'm not sure if T3 is possible but more effective intercooling is a step in the right direction . Retaining the Dash 9 or AC4400s engine would make the rebuild cheaper and using as many Evo parts as possible means common spares as well as proven electronics .
Our community is FREE to join. To participate you must either login or register for an account.