Serial curiosity

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Re: Serial curiosity

Postby Pneudyne » Mon Jun 15, 2015 7:41 pm

The initial 10 of the QR 1150 class were Erie-built, serials 31090 through 31099.

The repeat 3 from Goninan had Goninan serials 6 through 8. As you said, Goninan was a licensee, not a subsidiary. The Australian subsidiary was AGE, at least until it was sold to AEI.

At the time, International GE (IGE) seemed to operate independently of the Alco-GE alliance. Even the Erie-built exports with Alco 12-244 engines were referred to as IGE locomotives, not Alco-GE. The 70-tonner was an odd case. The documentation for it that I have seen refers to it as a GE locomotive, not an Alco-GE. But I think that it was included in some of the US domestic-oriented catalogues for Alco-GE locomotives as if it were an Alco-GE. Come to think of it, the Alco “World” export locomotive was originally presented as an Alco-GE product, but it was Alco-only by the time production started.

The Operating Manual for the first 10 of the QR 1150 class refers only to GE.

Apparently mounting of the couplers on the trucks was a weight-saving device, in that by doing it this way the main frames outboard of the truck pivots could be of lighter section. Also, the truck pivots were quite widely spaced relative to the frame length. (E.g. compare with the export U18C, which had about the same frame length.) Evidently QR wanted to obtain a similar weight spread to that of its Garratt steam locomotives. Some English Electric C-C diesel-electrics obtained at about the same time had similarly wide pivot spacing, although they had conventionally mounted couplers.
Cheers,

QR 1150 fc.jpg

QR 1150 fci,p.01.jpg

QR 1150 p.03.jpg
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Re: Serial curiosity

Postby Allen Hazen » Tue Jun 16, 2015 1:07 am

Pneudyne--
Thank you AGAIN! … You beat me to it as regards checking builders and builder numbers for the 1150 Class.
---
Can you say any more about the 1150 trucks? They seem to have more nearly equal axle spacing, and placement of the rotational axis closer to the centre axle, than the Alco/GE/F-M trimount trucks on North American units…

It is intuitively plausible that mounting the couplers on the trucks would reduce the stresses on the locomotive frame, and so permit lighter weight construction. (Of course, to really minimize stress on the frame, you'd use articulated trucks: common on heavy electric locomotives, and used by GE on a variety of lightweight diesels: narrow gauge derivative of the 44-tonner, for example.) The configuration of the QR 1150, with truck-mounted couplers but non-articulated trucks is very unusual in American locomotive design. The only other time I know of GE using it was on a pair of semi-experimental box-cab transfer locomotives (of 1800 and 2000 hp) built for the Illinois Central in the late 1930s.
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Re: Serial curiosity

Postby Pneudyne » Tue Jun 16, 2015 3:37 am

GE seemed to favour nominally centre-pivot three-axle trucks for its exports, and I am not aware that it ever used the trimount form that was much liked by Alco. In keeping with this approach, centre axle offset and centre pivot offset were generally small and no larger than needed to accommodate the centre traction motor, as was the case with the QR 1150. The latter also had rigid bolsters, which is what GE generally used for exports at the time. That it had migrated to the swing bolster type by around 1953, and then in 1956 adopted the floating bolster type for the export Universals suggests that in practice, it found that the rigid bolster type was not so good at higher speeds.

Articulated trucks certainly make for lighter main frames, but they are also hard on the track at higher speeds, particularly in terms of lateral railhead forces. They can be tamed by the use of pilot trucks, particularly of the four-wheel kind, and by the use of lateral restraint devices, such being found on many of the American 2-C+C-2 electric locomotives. GE’s use of articulated trucks on the six-axle versions of the 70-tonner may well have been both because this obviated the need to lengthen the main frames, which underlapped a pair of three-axle trucks, and because it allowed a lighter mainframe, thus minimizing the weight gain as compared with the base B-B model. The C+C version at least was a lowish speed locomotive, with a maximum of around 40 mile/h. With the IRCA Guatemala C+B+C road switcher, also essentially a low-speed locomotive, its chosen wheel arrangement may well have been the simplest and lightest way to accommodate eight axles. The C trucks had offset pivots, between the centre and inner axles (although they were not trimounts), and the apparent imbalance in weight distribution was corrected by the fact that some weight was transferred through the articulation joints to the centre truck, which was otherwise unconnected to the main frame. Thus, in theory at least, the centre truck was located entirely by the two articulation joints, and there was no need for the extended lateral motion control normally associated with the centre trucks of triple truck locomotives. One may imagine though the centre truck would have danced around quite a bit at say 40 mile/h, particularly on track and roadbed that might not have been quite the world’s best.

Another GE design with couplers mounted on non-articulated trucks was the 1938 steam turbine electric prototype. This had a 2-C-C-2, not 2-C+C-2 wheel arrangement, the two main trucks not being interconnected by an articulated joint. Whilst these two wheel arrangements look similar, in terms of dynamic behaviour they are quite different. 2-C-C-2 was a rare wheel arrangement; my count is 12 total worldwide including the two GE steam turbine-electrics.

The 4500 hp GTELs were another interesting case. These had the couplers attached to the outer ends of the span bolsters, but the latter were not linked by an articulated joint; they were inarticulate, one might say. Thus buff and drag forces ran through the span bolster outer sections to the main pivots, thence through the mainframe between the two main pivots. The same arrangement was used on the GE U50 and Alco C855. But for its later export four-truck locomotives, GE changed to mainframe-mounted couplers. This arrangement has more recently also been used by EMD for export four-truck locomotives, which have very slender span bolsters.

The GTEL prototype appeared around the same time as the Virginian EL2b motor-generator electric locomotives also built by GE. But these did have an articulated joint between the two span bolsters, so that the mainframe was free of buff and drag forces.

Cheers,
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Re: Serial curiosity

Postby obsessed railfan » Wed Mar 23, 2016 7:27 pm

Pneudyne wrote: Later on, GE did include these MRR locomotives in its Universal production lists as U12Cs, but I understand that this designation was not included in their maker’s plate data.


Interestingly, I have seen several instances in various paraphernalia from the 1956/1957 timeframe where GE themselves call the Manila roadswitchers both "91 Ton Roadswitcher", and also specifically "Modified U12C", so while they might be classified as 91 Ton on their builders plates, GE did consider them to be U12Cs long before they compiled their World User lists.

But just to add potential confusion, these engines are commonly referred to as UM12C on various railfan websites. While the UM12C did exist, it was a totally different model, and while GE has also used "M" in their export model designations for various modified or nonstandard models, I have never seen any factual evidence of the Manila units classified as "UM12C".
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Re: Serial curiosity

Postby bogieman » Thu Mar 24, 2016 9:57 pm

Pneudyne wrote:The 4500 hp GTELs were another interesting case. These had the couplers attached to the outer ends of the span bolsters, but the latter were not linked by an articulated joint; they were inarticulate, one might say. Thus buff and drag forces ran through the span bolster outer sections to the main pivots, thence through the mainframe between the two main pivots. The same arrangement was used on the GE U50 and Alco C855. But for its later export four-truck locomotives, GE changed to mainframe-mounted couplers. This arrangement has more recently also been used by EMD for export four-truck locomotives, which have very slender span bolsters.

Very interesting discussion Pneudyne, sorry I missed it earlier. I've looked all over the internet and cannot find any pictures of the U50 trucks that would show in detail how they interface to the underframe. I presume the interface is some kind of center bearing that transfers the vertical load to the span bolster but I wonder how deep it is to deal with the moment from the offset of coupler height to pivot height, or is the pivot depressed in the bolster to minimize the height offset? Or is the moment handled by some form of "constant contact" side bearings? These locomotives must have been designed for 1,000,000 lbs. buff load so the pitching of the trucks in this loading could be severe if not balanced somehow. Also, do you know if these trucks/span bolsters were an internal GE design or a product of General Steel or some other casting supplier?

When you mention that EMD has used this arrangement with frame mounted couplers on four-truck locomotives using slender span bolsters, are you referring to the SD70ACe-BB locomotives in Brazil?

I'd appreciate any knowledge you have of these trucks as they have always intrigued me yet I don't believe any locos have been preserved in the US having these trucks.

Dave
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Re: Serial curiosity

Postby Pneudyne » Sat Mar 26, 2016 1:32 am

I have never come across a detailed treatment of the span bolster and trucks used under the GE GTEL4500, GE U50 and Alco C855.

Articles on the GTEL4500 naturally focussed on its gas turbine prime mover, and when the GE U50 came along its runnin gear was dealt with quite simply by saying that it was recycled from the GTEL4500s.

The best that I have seen is the brief description in the Railway Gazette 1964 July 03 article on the Alco C855, from which I quote:

“The drawgear is accommodated in the bogie cradle frame, the drag box and headstock assembly being overhung at one end; the minimum curve for all condi¬tions is 21 deg., whether the units are in multiple, single unit, or running light.

“The main frames of both locomotives are carried on two twin-bogie assemblies, hence the wheel arrangement
Bo-Bo-Bo-Bo; the wheelbase of each twin is 24 ft 8 in, set at 44 ft in centres in the frame. The twin axle bogies are arranged with a 9 ft 4 in wheelbase and the traction motors facing towards the pivot.. The cradle assembly is pivoted directly to the underframe and transmits traction and braking loads through these fixed centres. The design of bogie and cradle or span-bolster is identical to that used under the gas-turbine locomotives of the Union Pacific Railway.”


(It seems inappropriate to post the complete article in this GE forum.)

So the span-bolster centre bearings did the whole job of transferring the load and the buff and drag forces, unassisted by any other devices. From the available drawings, those centre bearings were of reasonable diameter, and were recessed into the span bolster, which was reasonably deep at that point.

I should expect that the centre bearings have some freedom of movement on the pitch axis, to allow for traversing of vertical curves without undue weight transfer between the two trucks of each span-bolster. On the other hand, there would need to be very little freedom on the roll axis, so that the span-bolster rolls with the locomotive body, as it were, with that roll being controlled by the individual truck bolster springs.

The centre bearings were offset towards the inboard trucks. I’d guess that this was to compensate for the heavier nature of the span bolsters outboard of those bearings. I don’t know whether the span-bolster design was solely by GE or by GSC to GE’s requirements.

Some pictures of the later GE export B-B-B-B models, in this case for the Vale Mozambique BB40-9WM, may be found here:

http://www.railpictures.net/images/d1/9 ... 670631.jpg
http://www.railpictures.net/images/d2/2 ... 485055.jpg
http://www.railpictures.net/viewphoto.php?id=461094
http://www.railpictures.net/viewphoto.p ... 46&nseq=54

With the couplers mounted on the locomotive mainframe and not on the span bolsters, the latter are much lighter in construction.

bogieman wrote:When you mention that EMD has used this arrangement with frame mounted couplers on four-truck locomotives using slender span bolsters, are you referring to the SD70ACe-BB locomotives in Brazil?


Yes, that’s the one. I’ve seen pictures of the trucks and span bolsters, but I can’t now find them on the net.

Cheers,



Kratville UP Plan Package p.45.jpg
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Re: Serial curiosity

Postby bogieman » Sat Mar 26, 2016 9:52 am

Pneudyne wrote:
bogieman wrote:When you mention that EMD has used this arrangement with frame mounted couplers on four-truck locomotives using slender span bolsters, are you referring to the SD70ACe-BB locomotives in Brazil?


Yes, that’s the one. I’ve seen pictures of the trucks and span bolsters, but I can’t now find them on the net.


Pneudyne,

Thanks very much for the detailed answer and the arrangement drawing, that helps complete the picture of the GE bogies.

I'm very familiar with the new bogies under the SD70ACe-BB as I created that design and hold the patents on it. I admit I was inspired by the GE U50 but the motor arrangement and connections to the bolster and bolster to underframe are very different.

Dave
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Re: Serial curiosity

Postby Pneudyne » Sun Mar 27, 2016 12:32 am

Aha, now I see the reason for your forum name!

Running gear is a most interesting part of locomotive design, but one that has not had much in-depth treatment by the railfan press.

Regarding the SD70ACe-BB trucks, for what it is worth, here is my laypersons’ impression from when I first saw some pictures a few months back. It struck me as a relatively short, low-profile design that, although used under AAR-sized locomotives to facilitate their use on metre-gauge tracks, could also be used under compact-profile (say 9ft wide by 12 ft high) export-type locomotives without incurring much of a height increase or requiring much, if any, increase in frame length. And that this was apparently achieved by what I’d describe as a set of complementary features. The individual trucks have short wheelbases, which in turn indicated tandem-mounted motors, in and of itself advantageous from an adhesion viewpoint, but rare in two-axle truck practice, although not without precedent. The use of the outside equalized form – apart from conferring a distinctive and perhaps “retro” appearance - meant that the truck frames did not need to project above the tops of the wheels, thus aiding the low profile. And I am not sure, but it looks as if the 2nd and 4th traction motors, when viewed from the adjacent locomotive end, were suspended by pendulum links from the span bolsters, rather than being suspended from their own truck frames. Quite impressive!

Cheers,
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Re: Serial curiosity

Postby bogieman » Sun Mar 27, 2016 10:21 am

Thanks, your observations are correct; keeping the height down while having 43" wheels was the great challenge. I suppose any further discussion of this design belongs on the EMD forum.

Dave
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Re: Serial curiosity

Postby Pneudyne » Wed Apr 20, 2016 10:06 pm

Indeed.

I have started a new thread, "Eight-Axle Locomotives", in the "General Discussion: Locomotives, Rolling Stock, and Equipment" forum, so that all varieties can be covered without wanderinng off-topic. See: viewtopic.php?f=9&t=162408.

Cheers,
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Re: Serial curiosity

Postby Pneudyne » Mon May 22, 2017 8:33 pm

By 1963, GE was claiming to have built 23 000 locomotives:

DRT 196309 p.19.jpg


This advertisement is from Diesel Railway Traction for 1963 September, but it also ran in the July and August issues for that year.

At 61, GE was ahead on the country count. The GM advertisement in the same issue of DRT claimed Colombia as being the 39th country to order its locomotives.

Continuing the GE truck sub-theme in this thread, here is a picture of the floating bolster C truck used under the GTEL8500:

GE GTEL8500 Truck.jpg


Pneudyne wrote:GE seemed to favour nominally centre-pivot three-axle trucks for its exports, and I am not aware that it ever used the trimount form that was much liked by Alco.


Well, that might be the case for diesel locomotives, but it was not true overall as GE did apply trimount trucks to some of its electric locomotives, including the New Haven EP-5, the Virginian EL-C and the Pennsy E44.

The EP-5 had single inside-hung swing-bolster trimount trucks, inside equalized with the equalizer bars extended beyond the outer axles to accommodate stirrup-mounted springsets. Concomitantly, as this required the interaxle primary springsets to be centred, the pairs between the outer and centre axles were widely enough spaced to allow room for the transverse elliptical bolster springs. As such it was, I think, quite unusual. The EL-C had rigid-bolster trimount trucks with conventional outside equalization, appropriate for its mission, and bearing in mind that the EL-2B also had rigid-bolster trucks. Evidently Pennsy saw the same truck as being mission-appropriate for the E44, even though it probably worked at higher speeds than the EL-C. Presumably it could have had the EP-5 style or the GTEL8500 style of truck had it wanted an existent lateral motion with better high-speed riding.


Cheers,
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