New ES44C4 (A1A-A1A) Locomotive

[Leo_Ames]

Technology outgrew 4 motors. EMD couldn't even offer Santa Fe the cowl they initially sought with the GP60 while maintaining the desired axle rating, which led to the creation of the GP60M as a compromise to keep weight within load limits. And that was 25 years ago now. Locomotives have only gotten more complicated since then and there's simply no way to accommodate the latest 4,000 hp AC technology from EMD or GE within the confines of a 4 axle platform.

As for the C4 concept, it has absolutely nothing to do with saving weight. They're 416,000 lbs just like standard ES44DC's and ES44AC's. And I'm sure if a customer wanted, GE would be perfectly happy to ballast them to 432,000 just like CSX's ES44AH's.

This concept exists due to cost and commonality. These A1A AC machines are able to be sold at a cost comparable to the six motor ES44DC thanks to the savings of 2 AC motors and associated components compared to the ES44AC. And they offer comparable performance to the ES44DC as well (Starting tractive effort on the ES44DC is 142,000lbs with a continuous tractive effort rating 109,000 lbs compared to the C4 with 144,000 lbs and 105,000 lbs respectively).

And they do all that with more durable AC traction motors while offering increased parts commonality with their numerous six motored AC cousins.

It appears that BNSF thinks that the concept is a success. My evidence for this statement is that they are now rebuilding older GEs (C44-9W) in the 600 series into the the same A-1-A AC motored configuration. I think that the real objective is to reduce maintenance costs because AC traction motors don't have commutators or brushes.

The 600's are non-standard and have air brake and electrical systems that don't blend in well with their more modern Dash 9 stablemates, ES44DC's, and C4's.

So I wouldn't count on the rest of their Dash 9 fleet, which are distributed power compatible for an example where these ATSF Dash 9's are inferior and don't blend in well today thanks to their earlier electronics, receiving a C4 style rebuilding.

[es80ac]

So basically this is the end of the DC locomotives? It sounds like C4 is meant to replace six axle DCs?

[mp15ac]

Don't forget that besides BNSF that Florida East Coast has also acquired the C4's as well.

Stuart

[MEC407]

So basically this is the end of the DC locomotives? It sounds like C4 is meant to replace six axle DCs?

Yes. The C4 was never meant to be a replacement for, or alternative to, 4-axle locomotives; it was meant from the get-go to be a locomotive that would cost the same as the ES44DC, but have lower maintenance costs.

...there's simply no way to accommodate the latest 4,000 hp AC technology from EMD or GE within the confines of a 4 axle platform.

I respectfully disagree. The MPI HSP46 passenger locomotive uses a GEVO-12 engine and GE AC traction systems. MPI was able to package those, along with HEP equipment, into a 4-axle platform. Apparently it can be done. I suspect there's simply no market for such a thing on the freight side.

[NorthWest]

No new C-C road service locomotives (ES44DC, SD70M-2) have been built since 2010.

The main reason why we have not seen B-B AC freight locomotives is that there is no market. All the secondary roles are filled with cascaded road power and gensets, and for purposes of locomotive standardization railroads have gone with exclusively C-C locomotives for road power. This trend began before AC traction, as B-B purchases basically finished at around the same time the safety cabs were introduced.

[Leo_Ames]

...there's simply no way to accommodate the latest 4,000 hp AC technology from EMD or GE within the confines of a 4 axle platform.

I respectfully disagree. The MPI HSP46 passenger locomotive uses a GEVO-12 engine and GE AC traction systems. MPI was able to package those, along with HEP equipment, into a 4-axle platform. Apparently it can be done. I suspect there's simply no market for such a thing on the freight side.

That certainly plays havoc with that definitive statement that I attempted to make...

That said, I think they're a fair bit heavier than the GP60's of 25 years ago (Although their axle loading likely isn't the issue that it would've been back in say 1990). Also one wonders how much, if any ballast that they carry (i.e., is there much room in that footprint to grow and respond to new demands like Tier 4, or did they just squeeze by within weight limits)? There's also the question on if the frame is strong enough to withstand the rigors of heavy freight railroading? And then there's wheelslip concerns pushing 4,400 HP through a four axle locomotive.

Perhaps a better statement to make for why where not seeing new 4 axle mainline freight power is that Class 1 railroads with the notable exception of BNSF have all gravitated towards one size fits all where all such new acquisitions are concerned (As Northwest said). It's why most aren't even touching the C4 concept, let alone ordering DC models (EMD or GE, if a customer came knocking with a big order, would undoubtedly be happy to accommodate such a request despite not cataloging such a model in recent years) or exploring the 4 axle concept.

They want power that is equally adept in level or mountainous territory at the front of intermodals, coal trains, manifests, and whatever else you throw at them. And they're willing to pay a little extra to get that despite the added cost of those two extra AC traction motors.

[Pneudyne]

It is interesting to look at GE’s position on the A1A-A1A wheel arrangement as it was at the end of the 1950s, and as embodied in this article in “Diesel Railway Traction”.

DRT 195812 p.465.jpg

DRT 195812 p.466.jpg

This was aimed more at the export market and models, but also referred to domestic experience. One might summarize what GE said as where the B-B wheel arrangement was precluded on the basis of its relatively high axle loading, and so six axles were required, C-C was definitely a better choice than A1A-A1A. Thus it aligns with the notion that A1A-A1A running gear is a dead end.

In the pre-Universal era, GE had built export locomotives of the six-axle, four-motor kind. The first series of “shovel-nose” units for Argentina, with the Cooper Bessemer FVL-12T engine, had the A1A-A1A wheel arrangement. Essentially the same design was built for Chile, and in Australia Queensland Railways had a licence-built, A1A+A1A version of the 70-tonner.

But none of the initial range of Universal export models was offered with an A1A-A1A option. Presumably GE would have built such had any customer insisted and could not be dissuaded from its errant path. From the above article, it is evident that GE had done the basic work-up for what would have been the “U9A1A” and “U12A1A” models, which were then compared with the U9C and U12C respectively.

As it turned out, there was no call for the A1A-A1A wheel arrangement on export Universals through the 1960s and into the 1970s. Then from the mid-1970s, GE built the UM15A1A for Sudan (1974 and 1981), the UM10A1A for Hedjaz Jordan (1974), and the U18A1A for Indonesia (1976 and 1982). I understand that some of the Indonesian U18A1A fleet have been rebuilt as U18C, but this was following track and roadbed upgrades that allowed wider use of the latter type. It might be noted that PKA Indonesia had been acquiring the U18C type from 1975 onwards, so it had not made an “either or” choice between C-C and A1A-A1A, but rather had bought on a “horses for courses” basis. Since the 1970s U15 and U18 models were direct descendants of the original U12, the respective U15A1A and U18A1A variants can be considered to be direct descendants of the notional U12A1A that GE used in its article as an example of what not to buy. Of course, by the mid-1970s, GE’s 1958 article was probably forgotten by or unknown to those involved. Perusing old trade journal articles – and looking for “lines” of historical continuity where none may exist - is much more the prerogative of armchair observers than those at the coal-face making “here-and-now” decisions.

The EMD situation was quite different. During the 1950s and 1960s it had built many A1A-A1A versions of its export locomotives, including the B, G8 and G12, GL8 and G18, and G22. After the early 1970s though, its output of A1A-A1A locomotives tailed off. The irony of its significant A1A-A1A output is that apparently, during the design phase of the G8 and G12, there was high-level internal resistance to the idea of an A1A-A1A version. Rather it was thought (wishfully, I’d say) that a B-B diesel locomotive with a 37 500 lb axle loading would be suitable for use over track where steam locomotives had been restricted to 25 000 lb. Then, perhaps as a repeat of that aversion, the GL8 was issued as a B-B design, with the subsequent A1A-A1A variants (two such) looking like afterthoughts.

The two sides of the A1A-A1A issue are well illustrated by two examples. New Zealand Railways (NZR), from 1955 through 1967, installed a large fleet of A1A-A1A G12 locomotives, for use on its mountainous (2% grades) North Island main lines. During that period, it did look at using the C-C GR12, but its calculations showed that whilst the GR12 could certainly haul much larger trailing loads over the ruling grades, the point-to-point times would be increased to the extent that they were inherently unsatisfactory, and line capacity was not increased. So there would be no return on the extra capital employed by using the GR12 rather than the G12, and no justification for buying it. I suppose one might say that the ton-miles per hour factor was pretty much the same for the GR12 and G12. Successor to the G12 in the North Island was the GE U26C. This was a C-C, with 2600 hp on 215 000 lb, and so 83 lb/hp. The G12 had 1310 hp on 130 000 lb adhesive weight, 99 lb/hp. For NZR, the A1A-A1A version of the G12 made sense.

QR, with some steep grades but overall a flatter profile, also acquired its first G12s in 1955, this being Clyde-GM’s entry point to the QR business. Here one supposes that Clyde-GM wanted to offer a (slightly modified) standard model, and the G12 was seen as the best fit. QR had already started main line dieselization with 200 000 lb C-C locomotives of around 1100 to 1200 hp from GE and English Electric (EE). Apparently it expected the 1310 hp G12 to fit into the established operating patterns, and haul the same trains as the GE and EE locomotives. Unsurprisingly, the A1A-A1A G12, in this case with 134 000 lb adhesive weight, was found to be rather slippery, and QR asked Clyde-GM for a C-C variant, which appeared as the GR12 (also confusingly advertised by Clyde-GM as the G12C) in 1957, ahead of EMD’s announcement of the same model in 1958. For QR, the A1A-A1A version of the G12 was a dead-end.

So, whether the A1A-A1A wheel arrangement is a wise and appropriate choice or a dead end is very much dependent upon the situation, and it can fulfil both roles very well. That it has been inappropriately applied in the past has given it a somewhat clouded reputation, as evidenced by the simple existence of this thread. On balance though, the ES44C4, deployed for those operations where it is an ideal fit and not expected to be a “do everything” locomotive, looks to fall into the “wise and appropriate choice” category. I imagine that it is most appropriate for larger roads with the scale and operating discipline to be able to segregate locomotive pools than for smaller roads where “one size fits all” is the inevitable operating regime, whether de facto or de jure.

Cheers,

[v8interceptor]

So basically this is the end of the DC locomotives? It sounds like C4 is meant to replace six axle DCs?

Yes. The C4 was never meant to be a replacement for, or alternative to, 4-axle locomotives; it was meant from the get-go to be a locomotive that would cost the same as the ES44DC, but have lower maintenance costs.

...there's simply no way to accommodate the latest 4,000 hp AC technology from EMD or GE within the confines of a 4 axle platform.

I respectfully disagree. The MPI HSP46 passenger locomotive uses a GEVO-12 engine and GE AC traction systems. MPI was able to package those, along with HEP equipment, into a 4-axle platform. Apparently it can be done. I suspect there's simply no market for such a thing on the freight side.

From discussions on other forums the consensus (including from folks who work in the industry) seems to be that the monocoque body/frame system that the newer high horsepower passenger units employ would not be very optimal in freight service, at least in North America. And taking the machinery of an HSP46 and putting it on a Dash 8 40- B style frame would produce a seriously overweight (for four axle trucks) locomotive.

[MEC407]

That may be true, but the HSP46 is not a monocoque design. It's a frame with a carbody over it, just like the MP36, F40 series, etc.

The '46 weighs 288,000 LBs (Dash 8-40BW = 280,000 LBs), which is heavy but not unreasonably heavy for a 4-axle freight locomotive by today's standards, and that includes HEP equipment which would be absent on a freight loco. A narrowbody freight-style carbody would presumably also weigh less than a widebody passenger-style carbody.

[v8interceptor]

That may be true, but the HSP46 is not a monocoque design. It's a frame with a carbody over it, just like the MP36, F40 series, etc.

The '46 weighs 288,000 LBs (Dash 8-40BW = 280,000 LBs), which is heavy but not unreasonably heavy for a 4-axle freight locomotive by today's standards, and that includes HEP equipment which would be absent on a freight loco. A narrowbody freight-style carbody would presumably also weigh less than a widebody passenger-style carbody.

In the current production AC traction passenger locomotive is the HEP equipment that bulky/heavy in comparison to commuter units that use HEP Gensets?
Does the system require an additional Ac inverter(s), etc..

Most comments from I've read from people in the industry (including engineers who run them) seem to indicate that the widecab BB units that ATSF bought ( GE 40ws and EMD 60Ms) had issues due to their high axle loadings. I recall reading an interview with a Santa Fe hogger who loved running conventional cab GP60's but hated the wide cab 60s due the the extra weight overloading the suspensions and thus resulting in a rough ride.
The fuel tank capacity issue I suspect , would be a non-negotiable item for Class 1's at the moment. GE and BNSF together looked at both 4 and 5 axle designs to meet the Railroads requirement for an AC traction ES44dc equivalent so it's not like the A-1-A solution was a hastily thrown together solution..

[MEC407]

I've also heard many complaints about the GP60M. I haven't read/heard similar complaints about the Dash 8-40BW. (Not saying there aren't any; just saying I've never come across any. The issues with the GP60M are pretty well known.)