GE U50 and GTEL informations

The original poster, Lowflyer, seems to be below the horizon somewhere, and whilst his main interest appears to be the span-bolster locomotives, he also mentioned the second generation GTELs, assumed to be the GTEL8500s, and not the second batch of the GTEL4500s:

lowflyer wrote: ↑Tue Nov 24, 2020 6:45 am I can't find also if the first and second generations of the GTEL used the same solution, B+B trucks with the span bolsters.

Thus at least a brief commentary seems appropriate.


The second generation 8500 hp UP turbines, GTEL8500, had a more conventional wheel arrangement, using two permanently coupled C-C units, plus a fuel tender. They had GE floating bolster trucks.



I don’t think that this reflected dissatisfaction with the span bolster running gear of the GTEL4500. Rather, the GTEL8500 needed 12 driving axles, and that was a convenient way to accommodate them. Also, it was convenient to accommodate the equipment in two carbodies. The driving cab and auxiliary powerplant were accommodated in the leading unit, which was of conventional cab unit construction with load-bearing truss-type sidewalls. The trailing unit, which accommodated the turbine and generators, was as far as I can determine of the strength frame type, with an easily removable (in part at least) non-structural body.

Given that GTELs were not amenable to MU operation, as the UP found out, the need for more head-end power meant a more powerful single unit, hence the GTEL8500. I suspect the GTEL4500 power output was more a reflection of what could be done, rather than what was needed for UP operations. Nonetheless, it fitted at a time when UP was using 4500 hp three-unit diesels eastbound from Ogden and up the Wasatch. Within a few years, much more was needed, hence the GTEL8500. Once the GTEL8500 fleet was in service, the GTEL4500s were probably of lower utility unless MU’d with diesels, which of course diluted their benefits. Plus the maintenance cost curve apparently rose quite steeply at somewhere around the three-quarter million mile mark, give or take. So I don’t think that there was all that much overlap between GTEL4500 and GTEL8500 operations once the full fleet of the latter was available. In the case of the GTEL8500s, their demise in part was attributable to the rising cost of heavy fuel oil (as the industry undertook more cracking and otherwise conversion to lighter and/or higher margin streams). Plus what heavy fuel was left was likely poorer in quality when measured against the GTEL requirements.

Returning to the span-bolster running gear, that all/most units were recycled for use under the U50 fleet (and perhaps the Alco C-855s) suggests that it was viewed a satisfactory from both the performance and structural viewpoints. I haven’t seen anything to suggest that there were any structural problems. On the other hand, the GTEL8500 C-trucks recycled for use under the GE U50C fleet were reported as eventually suffering from fatigue cracking.


Cheers,

As always, great information. Any idea which company designed these 3 and 4 axle bogies? I am thinking it was GSI or Commonwealth rather than GE.

Pneudyne--
Re: frame cracking in re-used trucks from the 8500hp GTEL: we had a string on this forum a while back in which it came out that the U50C was very, VERY, heavy: a good deal heavier than the "goal" weight of the design. (GE, by the way, released a drawing of the U50C when the model was announced, showing it riding on standard FB3 trucks (as used on other 6-axle U and Dash-7 models): picture published in a short article announcing the model in "Railway Age").)
Bogieman--
Re: design of the trucks. Given GE's history in the locomotive business, surely some of their own engineers would have known a good deal about truck design? So even if the detailed design was GSI or Commonwealth, it would have been in consultation with GE's engineering people. (I know that seriously innovative truck designs -- like EMD's steerable trucks (Grin!) -- are patented. Would the designs of the trucks on the GTEL 4500 and GTEL 8500 have had design patents? I tried looking up patents for them a few weeks back, with no success: but I don't know whether my lack of success is due to there not being patents on the designs or to my lack of skill in searching for patents on the Internet!)

One last thought about the history of the span bolsters. GE built a total of 26 4500 hp GTEL locomotives, and a total of 26 U50. If, instead of re-using the span bolsters from the prototype on one of the production turbines, GE stashed them somewhere on the property at Erie for a dozen years (scrap steel wasn't all THAT valuable, and someone at GE might have thought they could come in handy on another prototype unit, I suppose), then it would have been possible for all the U50 units to have been built with "recycled" span bolsters.
I'm sorry, but I don't have any real information to back up my speculations: thank you Pneudyne and Bogieman for your information!

Allen Hazen wrote: ↑Mon Feb 08, 2021 11:04 pm
Bogieman--
Re: design of the trucks. Given GE's history in the locomotive business, surely some of their own engineers would have known a good deal about truck design? So even if the detailed design was GSI or Commonwealth, it would have been in consultation with GE's engineering people. (I know that seriously innovative truck designs -- like EMD's steerable trucks (Grin!) -- are patented. Would the designs of the trucks on the GTEL 4500 and GTEL 8500 have had design patents? I tried looking up patents for them a few weeks back, with no success: but I don't know whether my lack of success is due to there not being patents on the designs or to my lack of skill in searching for patents on the Internet!)

I wasn't trying to disparage GE's engineers, only wondering if they had a staff of truck designer's or if that was an item they outsourced. As an example, even though EMD designed trucks in house, the foundation brake rigging design and production was outsourced to American Steel Foundries until 1973, when EMD finally took over that design responsibility. I, too, have searched for patents and came up empty.

Bogieman--
Sorry, I did sound as if I was springing to the defence of GE's honour about truck design, didn't I? ... Obviously there would have to be consultation between the GE engineers and the foundries', and I would guess that in different truck designs there might be a gradation in the proportion of the design work done on each side. ... One of the things that stands out in rail fans' discussions of GE locomotives is that the FB3 truck (used on U30(etc)C, C30(etc)-7 and six-all Dash-8 locomotives) came with visibly different frames from the GSI and Adirondack foundries: so clearly GE was willing to outsource at least the detail design.
--
On another truck topic, you said that EMD people never speak of a "Blomberg" truck, but call the thing rail fans call that a "GP" truck. (I think Martin Blomberg was its primary designer, and also the primary designer of the A1A truck used on E units.). But the truck was introduced on the FT freight locomotive a decade before EMD brought out the first GP locomotive, so it wouldn't originally have been called the "GP" truck!
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I fear my general ignorance is showing: my contributions seem to be getting more and more trivial! Thank you very much for all the non-trivial things you have posted!

At EMD before the GP model was introduced, the 2-axle swing hanger truck was simply called the "freight truck". I suspect it was the introduction of the SD model that made that designation unclear and led to calling it the GP truck.

Bogieman--
Thanks! That makes sense as an account of the "historical linguistics" of the "EMD dialect"!
(The SD truck, I learned when I lived in Australia, was apparently developed in response to Australian requirements: A history(*) of the relevant locomotives (VR B class) of Victorian Railways tells a story about EMD developing this truck as part of the project, with a photo of a test in which prototype trucks were put under a flatcar for tracking, etc, tests. I assume that the idea of using them on an elongated road switcher occurred to EMD fairly quickly: the first SD-7 went into service a few months before VR's first B.)
---
(*) Peter Bermingham, "The ML-2 Story." (The B class locomotives -- most of the fleet was still in use when I went to Melbourne in the 1980s -- were elongated -- twin cab -- F7, built for a railway whose permissible axle loadings required six axles to spread the weight.)

I have not found any patents (from any suppliers) that relate to the trucks and span bolsters used under the GTEL4500 and the later similarly-shod locomotives. That is not to say that they do not exist. In my experience, patent searching is a hit-or-miss affair. Sometimes you find more than you were looking for fairly quickly, other times a long series of incremental and iterative searches produces very little.

Neither do any of the sources at my disposal indicate who supplied the span bolsters and truck frames for these locomotives. Apparently the GTEL4500 was described in the 1949 July issues of both “Railway Age” and “Railway Mechanical Engineer”. I have not seen these articles, but I should say that there is a good chance they include major components suppliers lists.

All of that said, GE patents for trucks and running gear in that era generally seem to be scarce; in fact, I have found only one such for the pre-1970 period. (It may be noted that there are a reasonable number of GE patents for other aspects of locomotive engineering, such as control systems. So in general, GE patents are showing up in searches.)

Nonetheless, GE did at times seem to incorporate some of its own ideas into running gear design. One, c.1953, was its unusual (or perhaps ersatz) swing motion mechanism applied to export-model C trucks that were basically of the rigid-bolster type. (And I have yet to find a clear diagram of this.) The floating bolster with four rubber spring mounts from c.1955 seems to have been a GE development, albeit more a combination of existing ideas. The idea of supporting the bolster on rubber pads on the truck frame alone seems to have been patented by GSC (US2517671, 1950 August 08.) Nonetheless, although others have patented what might be called incremental truck developments, it seems that in general GE elected not to do so. The C-truck used under the GTEL8500 looks as if it might have been a refinement of a basic idea of superimposing a floating bolster upon an existing rigid-bolster design. The base design, with primary spring sets centred between adjacent axles, would not easily have accommodated conventional swing hangers and spring planks, so other means of providing for lateral motion and secondary springing were needed. And there may have been a developing aversion to the level of complexity involved with swing hangers, etc., given that simpler designs without the swing hangers, such as the EMD flexicoil, were already in service. The GTEL8500 trucks make an interesting comparison with those of the New Haven EP-5 class electrics.

The one pre-1970 GE truck-related patent that I have found is US3054361 of 1962 September 18, for an inter-truck guiding control mechanism. This was an incremental case, being based upon original work by SLM (Switzerland), UK patent GB611237A, with initial increment work by English Electric (GB742129). GE would have done this for South African Railways (SAR). SAR had been introduced to the transverse inter-truck coupling with its English Electric-built 5E class DC electric locomotives, and subsequently specified it for most of its mainline diesel and electric locomotives. GE’s first application would have been on the SAR 32 class diesels (GE U18C1 model) of 1959. These used the GSC 1-C trucks.


Cheers,

Pneudyne--
Re: articles in "Railway Age" and "Railway Mechanical Engineer"
I have access to these through my university library: someone has digitized a lot of back issues for the benefit of university-based researchers. (Contact me if you want ...)
The July 1949 issue of "Railway Age" doesn't have an article on the GTEL. (It has an article, by the electrical heads of the Virginian and the Great Northern and a "project engineer" at GE, on the performance of the then-new motor-generator electric locomotives, footnoted as an "abstract" of a paper they had given to the ASME. It also has an article describing the EMD "test car": the one that looked like an F-type B-unit but with odd window arrangement and no roofline air vents.)
I've looked at the article in the July 1949 "Railway Mechanical Engineer," and I don't think it has the sort of "who made which parts" table that many RME locomotive articles include (but I'll check again). It's by Perry Egbert (of Alco) and the head of the GE locomotive division, has some photos of the prototype GTEL in GE colors, including one of a span-bolster truck that isn't as good as the photo you have linked, and is more about "why we think this idea is worth investigating with a test locomotive" than about technical details.
--
In my experience too, patent searching seems a bit "hit or miss." Whether the online data bases have search facilities that people in patent attorney's offices know how to use but I don't is another question!

Hi Allen:

Thanks for looking up the RA and RME articles.

These were footnoted references in the Locomotive Cyclopedia (LC) 1950-52, available on-line at: https://babel.hathitrust.org/cgi/pt?id= ... =1up&seq=1.

I have attached an excerpt of those references, which were from page 414 of LC 1950-52. There are also some 1950 journal issues noted that possibly might be helpful.


Nothing I have found in LC 1950-52 discloses who designed/built the GTEL4500 span bolster running gear. However, from page 400 we know that GSC/Commonwealth supplied the running gear for the more-or-less contemporary GN W-1 class B-D+D-B MG electrics built by GE. So GSC seems to have been a probable more than a possible for the GTEL4500 and VGN EL-2B cases. Re the latter, page 389 has a (not very good) picture of its span bolster assembly, which looks quite a bit different to that of the GTEL4500.


Turning to patents, I should imagine that patent attorneys have access to sophisticated search software that allows retrieval of “prior art”, etc. But such is likely to be costly and not available to “mere mortals”.

Meanwhile I have found some more GE truck-related patents that refer not to whole trucks, but parts thereof or accessories thereto. So perhaps that is where GE put its effort. US 2044576 of 1936 June 16 covered a lateral restraint device for guiding trucks. This type of mechanism was used a stability aid for the pilot trucks of higher-speed 2-C+C-2 locomotives and the like. US 2111429 of 1938 March 15 covered a lateral restraint device of the type typically used at the inner end of one of the main trucks in 2-C+C-2 locomotives. For example I think that both types were found on the New Haven 2-C+C-2 electrics of the late 1930s. And the GE STEL 2-C-C-2 prototypes had lateral restraint devices on the pilot trucks. A longitudinally-oriented main truck lateral stabilizer was used on the GN W-1, because the main trucks were separated somewhat and connected by a double-hinged bar rather than the customary single-point joint. There might be a patent for this, but as yet I haven’t found it.

The main truck lateral restraint device provided tight control of relative movement between the trucks over a small angular range, with free movement beyond that. The idea was to inhibit the oscillatory tendencies of articulated trucks on tangent track, which left unchecked caused high lateral railhead forces. That was quite the opposite of the later lateral inter-truck guiding device, which, assuming that each truck was independently stable in an oscillatory sense, allowed fee relative movement on tangent track, but kicked in on curves to allow the leading truck to guide the following truck. As mentioned above, the GE device in this category was probably first used on the SAR U18C1 which had GSC 1-C trucks. The latter were covered by US patent 2994284 of 1961 August 01. Therein it was stated: “It is intended that a locomotive cab will be pivotally supported on a pair of these trucks arranged in back-to-back relationship under the supported locomotive cab and it will be understood that when so used the trucks will be connected by an inter-bogie control means of a type well-known in the art, whereby to properly guide the trailing truck during its reverse operation.” Thus, GSC expected the lateral guiding device to be used, and one could say that in this case GSC and GE were working synergistically.

Another GE truck-related, but not “whole truck” patent was US 2720846 of 1955 October 18, which covered sliding pivot design for articulated trucks done in a way that allowed full interchangeability between the fixed pivot and sliding-pivot trucks. This appears to have derived from the work it did for the narrow-gauge, C+C version of its 70-ton model, and the C+B+C road switcher built for Guatemala and Colombia.

Whilst GE evidently favoured the span-bolster arrangement where an all-adhesion locomotive with eight driving axles was required, Westinghouse had a different view. It is easier to quote from its patent US 2610586 of 1952 September 16: “The number of driving wheels under a locomotive can be increased by providing three or more four-wheel trucks under each cab of the locomotive. However, when more than two four wheel trucks are provided under a locomotive cab the trucks must be of a special type or sub-frames must be utilized. The locomotive structure can be simplified and the cost reduced by eliminating the sub-frames.” This patent described the thinking that led to the Westinghouse B-B-B-B GTEL prototype of 1950, and the Pennsy EL3b B-B-B rectifier electric prototype of 1951, although it did not appear to cover the roller-platform lateral motion device that was actually used. That may have been covered by a separate patent. Westinghouse also patented a corresponding trimount-type C-truck (US 2558069 of 1951 June 26), although I don’t think that it was used on the Pennsy EL2c prototypes. Rather the photographic evidence suggests that they had single swing-bolster trimount trucks, a type for which GSC held patent US 2703057 of 1955 March 01.

When it came to the GE U50, whether alternative ways of providing for eight driving axles were considered is unknown. But the fact that UP wanted to trade-in its GTEL4500 span bolster sets was probably sufficient justification to set side serious consideration of alternatives, such as D-D or the Westinghouse form of B-B-B-B. UP was evidently happy with the riding and tracking characteristics of the GTEL4500 running gear, and did not see the putative weight penalty as being a major problem. The fact that later GE chose the span bolster form for export metre gauge eight-axle locomotives (albeit with locomotive mainframe-mounted couplers) tends to validate its 1940s decision in respect of GTEL4500.


Cheers,

Pneudyne--
Thanks for the page references!
---Re: article in July 1949 "Railway Age". I feel very stupid: I had only looked at one July 1949 issue, and "Railway Age" was a weekly in those days! Looking at the RIGHT issue... It's basically the same Egbert and Wilson article as in "Railway Mechanical Engineer" (concluding two paragraphs changed, otherwise I think I spotted one very minor editing change), with some different illustrations: photo of full locomotive as repainted in Union Pacific livery, but (alas) the same not very informative photo of a truck/span bolster assembly.

---Re: Report in July 1950 "Railway Age". A couple of paragraphs reporting the initial phase of testing on the U.P. (Fuel consumption high enough that it would be uneconomic to use diesel fuel except for short periods, but Bunker C fuel consumption reasonable. At press time the locomotive was back at GE for inspection and minor tweaking, expected to return to U.P. for more tests.) ... This was part of a more general report on gas turbine locomotives: (i) research with a stationary installation of a coal-fired turbine was going on at Alco's Dunkerque plant (ii) Westinghouse was nearing "installation" on its gas turbine electric locomotive (iii) Lima was expecting delivery of a power plant for its free-piston turbine electric locomotive by the end of 1950 (hmmm-- maybe this indicates that Lima was still working on it up to the merger with Baldwin?) (iv) Progress was being made on a joint Baldwin/Santa Fe project, completion expected by the end of 1952 (hmmm-- as I recall, the Lima-Baldwin merger involved Westinghouse taking up a major stockholding position in the merged company: perhaps this Baldwin project was killed off in favour of the Westinghouse project?)

---Re: report in "Railway Mechanical and Electrical Engineer". Out of luck on this one: the collection ("American Periodicals from the Center for Research Libraries") that I can get through my university library has "Railway Mechanical Engineer" to the end of 1949, but apparently not "Railway Electrical Engineer" (sniff-- that title, rather than RME, seems to have been what carried descriptions of many electric locomotives) or of the post-1949 merged title.

Re: Westinghouse patent US 2610586 of 1952 September 16 (mentioned in Pneudyne's post, two up):
A fair number of subsequent electric locomotives (Queensland Rail's fleet, and in the U.S. the EMD test/demonstrator E10 unit of the 1970s) and some diesels (New Zealand's DJ-- I think a similar design was used in a diesel widely used on non-electrified lines in Japan) have had BBB running gear. How much they owed to Westinghouse's thinking on the subject I don't know. ... The Pennsylvania Railroad experimentally installed traction motors on the end trucks of one of their 2C2 electrics (P5 class), making a BCB. But this was a fundamentally different approach: the C part of the running gear was on the rigid frame, so any lateral motion was in (one or both) trucks, whereas Westinghouse, i.i.r.c., allowed some lateral movement in the middle truck(s) with the end ones having fixed pivots on the main frame.

The history of triple-truck locomotives is quite diverse. Westinghouse patented a single-frame, articulated truck, B+B+B layout in the early 1920s.


The first build was by GE, a single-frame B+B+B DC electric for FC Mexicano in 1925. Alsthom built a small single-frame B-B-B diesel-electric for Madagascar in 1939, then went on to build quite a few B-B-B export locomotives from the 1950s onwards.

In 1940, FS, Italy introduced its E636 class, an articulated body B-B-B in which the centre truck was effectively a Jacobs bogie, a form that had been patented in 1905 and which had previously been used for passenger vehicles, both powered and unpowered. The E636 was successor – with higher top speed capability - to the E626 of the late 1920s. That was also a B-B-B, but of the rigid frame type, effectively a 2-B-2 with powered pilot trucks (cf. the Pennsy B-C-B derivative of the P5). The articulated body form was built for FS until the late 1980s, with a total well above 1000.) The articulated-body form had some later use outside of Italy, including for diesel-electric and diesel-hydraulic locomotives. As far as I know, the first non-Italian use was for the New Zealand Railways (NZR) Ew class DC electric, B-B-B, of 1952.

There was a solitary SNCF, France single-frame B-B-B DC electric prototype in 1948, not repeated, although a mechanically similar AC-DC prototype was built in 1955. Then in 1950 came GE’s C+B+C diesel-electric road switcher for IRCA, Guatemala, later also built for Colombia.

That brings us to the Westinghouse E3b prototypes for the Pennsy, in 1951, with running gear described by a US patent, which also covered the non-span bolster B-B-B-B assembly for the GTEL prototype, and the roller-type lateral motion mechanism.


Thereafter there was more diversity. A significant event was the adoption of the single-frame B-B-B form by JNR, Japan for its DF50 class standard diesel-electric locomotives in 1957. Triple-truck had become the standard form in Japan by c.1962, at which time there were series production B-B-B diesel-electric, DC electric and AC electric locomotives, and B-2-B AC electric and diesel-hydraulic locomotives. There was also a B-1-B diesel-hydraulic prototype that spawned a later production series.

The Japanese builders did adopt what looked like a derivative of the Westinghouse roller-type lateral motion device in the early-to-mid-1960s, although used only for the centre trucks, and combined with the characteristic long outboard flexicoil secondary springs. As far as I know the first Japanese triple-truck export was the NZR Dj class diesel-electric, B-B-B, in 1967. This did have the roller-type lateral motion, with flexicoil springs, for the centre truck.


Cheers,

Pneudyne wrote: ↑Mon Feb 15, 2021 9:52 pm
Meanwhile I have found some more GE truck-related patents that refer not to whole trucks, but parts thereof or accessories thereto. So perhaps that is where GE put its effort. US 2044576 of 1936 June 16 covered a lateral restraint device for guiding trucks. This type of mechanism was used a stability aid for the pilot trucks of higher-speed 2-C+C-2 locomotives and the like. US 2111429 of 1938 March 15 covered a lateral restraint device of the type typically used at the inner end of one of the main trucks in 2-C+C-2 locomotives. For example I think that both types were found on the New Haven 2-C+C-2 electrics of the late 1930s. And the GE STEL 2-C-C-2 prototypes had lateral restraint devices on the pilot trucks. A longitudinally-oriented main truck lateral stabilizer was used on the GN W-1, because the main trucks were separated somewhat and connected by a double-hinged bar rather than the customary single-point joint. There might be a patent for this, but as yet I haven’t found it.

Some correction and clarification is required here.

Upon further study I’d say that US 2111429 was specifically applicable to the 1938 STEL with 2-C-C-2 running gear, and not to the 2-C+C-2 electric locomotives. In the case of the STEL, it appears that to some extent, GE was endeavouring to replicate the lateral stability control system of the 2-C+C-2 locomotives, but without the benefit of an interconnection between the main bogies. Whereas in the 2-C+C-2 case, a single lateral stability device at the inner end of one of the main trucks sufficed, for the 2-C-C-2, each main truck needed its own device. Furthermore the two devices were unequal, that for the trailing main truck having a stronger restoring force because as well as inhibiting oscillation on tangent track, it also served to steer that truck into curves. That would explain why the STEL pair were intended to be operated elephant-style, rather than back-to-back, when MU’d.


The main truck lateral stability device for the 2-C+C-2 case was described in GE patent US 2111428. (The part locomotive shown in the sketch looks vaguely familiar……)


I still have not found any patent documents related to the span-bolster B-B-B-B running gear, nor for the inter-truck stabilizer used on the GE B-D+D-B motor-generator electrics.


Cheers,