• Blind drivers vs. lateral motion devices?

  • Discussion of steam locomotives from all manufacturers and railroads
Discussion of steam locomotives from all manufacturers and railroads

Moderators: slide rules, Typewriters

  by Pneudyne
 
Allen Hazen wrote:I know some railroads used thinner flanges on the tire of some drivers. Is setting the tires in different positions -- closer to the centre-line of the locomotive on some, further on others -- an alternative means of getting the same effect with tires of uniform profile?
As far as I know, that was done. I imagine that it avoided the need to use thin flanges, which would probably not survive as many tyre turnings as the regular type. On the other hand, there was probably a limit to how far inwards the flanges could be placed before they were likely to foul check rails.


Cheers,
  by Allen Hazen
 
The figures on the diagrams range from 53 inches up to, I think, 53 3/8 inches-- I assume this is the distance between the inside edges of the tires on the two ends of the axle. Means there was about 3/16 inch (approximately 4.m millimetres) difference between the outermost and innermost placements of the tire. Not very much: as witness the fact that variable tire-spacing was combined with lateral motion devices on PRR's long-wheelbase locomotives.
  by Pneudyne
 
Allen Hazen wrote:About that Q-2 book mentioned in my previous post...
(3). Also included, some internal documents, including a letter from a P.R.R. purchasing agent to Alco, enquiring about the royalties Alco would want for seven lateral motion devices. (That one surprised me: I had assumed that the devices themselves were manufactured by Alco, and that any patent royalties would have been included in the price...) Explaining that "Because of some design details, only 7 of the American Locomotive Company devices will be used; the remaining 3 will be a Pennsylvania Railroad design."
The Alco LMD itself probably could not be copied directly without patent infringement, but that did not preclude other designs. As far as I know, Franklin offered an alternative design, but it does not seem to have been much used. Evidently there was enough “wiggle room” between the patents for PRR to design its own version.

Strange nonetheless. How the 7 Alco and 3 PRR units would be distributed is unknown, but however it was done at least two axles would have each had a pair of Alco units, and at least one axle would have had one Alco and one PRR unit. Maybe there were space constraints and the PRR unit was dimensionally a better fit in some locations? If that situation obtained, that the Alco unit was applied where it fitted suggests that it was viewed as the better of the two.

There is a picture of the Alco device at: https://www.facebook.com/NashvilleSteam ... 230215746/" onclick="window.open(this.href);return false;.

But the accompanying explanation can’t be right, as a feature of the device was that there was no lateral spring pressure on the axleboxes when a driving axle was centred with respect to the frame. Rather when the axle moved laterally, the axlebox moving inwards contacted the spring and started to compress it. The other end of the spring (or really two springs separated by a collar) could not move proportionally, as it was effectively up against the frame.

Patent royalties may have been worked out on case-by-case basis with some kind of sliding scale, perhaps to keep this aspect at “arm’s length” from pricing deals that might have been subject to ICC scrutiny.



Cheers
  by Pneudyne
 
Here is another descriptive item on the Alco LMD, from "Railway Age" 1932:
Alco Lateral Cushioning Device RA V92 #19 p.781 1932.png
Cheers,
  by Pneudyne
 
Some further background on the earlier application of lateral motion devices is provided by this article, by J.G. Blunt of Alco, from Railway Mechanical Engineer (RME) for 1927 April. Clearly, Blunt was taking something of an holistic approach to the issue of steam locomotive curving, riding, tracking and the wellbeing of itself and the track.

RME 192704 p.202e.png
RME 192704 p.203.png
RME 192704 p.204e.png

More to follow.


Cheers,
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  by Pneudyne
 
Some further background on the earlier application of lateral motion devices is provided by this article, by J.G. Blunt of Alco, from Railway Mechanical Engineer (RME) for 1927 April. Clearly, Blunt was taking something of an holistic approach to the issue of steam locomotive curving, riding, tracking and the wellbeing of itself and the track.


RME 194111 p.483e.jpg
RME 194111 p.484e.jpg

More to follow.


Cheers,
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  by Allen Hazen
 
Dear Pneudyne--
Thank you for these. I've been either busy or distracted, and haven't had time to read all you have posted, but I will (and will comment if I think I have anything to say).
---
I see you now have access to "Railway Mechanical Engineer." On another topic we have discussed -- the 4-8-8-4 gas turbine electric locomotive that Baldwin, the Santa Fe, and Allis-Chalmers worked on in the late 1940s: RME published an article by an A-C person on it (and another GTE design which, it would seem, didn't even get as far as the Santa Fe Centipede) in October (I think) 1948. One interesting bit of detail I noticed in a first skim had to do with traction motors. Baldwin's DIESEL Centipedes (both the Postwar version with two 608 engines and the wartime prototype "Big Engine" with the multiple V-8 diesels) used Westinghouse 370 t.m.: the type used on Baldwin's conventionally trucked diesel road locomotives. A nose-suspended design, like most t.m. used in American diesel practice. The A-C proposal would, of course, have used something different: some A-C motor. But if the article is to be trusted, it would NOT have been a "370-clone": it was to be supported on the frame and flexibly connected to the axles. Which would have reduced unsprung mass: this might have been the most track-friendly locomotive design of its period!
  by Pneudyne
 
Hi Allen:

Thanks for that.

I forgot to mention in my most recent posting that just a few days back, and quite by accident, I found on-line availability of both “Railway Age” and “Railway Mechanical Engineer”.

Railway Age is at: https://archive.org/details/pub_railway-age

Railway Mechanical Engineer (and its successor, Railway Locomotives and Cars) is at: https://archive.org/details/pub_railway ... s-and-cars

Unrestricted downloading is available up to and including 1961. For later issues, there is a login process that I haven’t tried. Perhaps not the world’s best copies – scans of monochrome microfilm records, I think, but a great source of information, and a major consumer of time. I am still sifting through items of interest – haven’t got to GTELs yet.


Cheers,
  by Pneudyne
 
By 1937, Blunt of Alco had further developed his thoughts on lateral cushioning, and these were published in Railway Age for 1937 January 16.

RA 19370116 p.155.png
RA 19370116 p.156e.png

By now he was advocating the use of the lateral cushioning device on the second driving axle, if that were an intermediate type.

An interesting observation was that it was easier to obtain smooth curving on a single-ended machine than on the double-ended type. That aligns with the fact that the Pennsy had some difficulty in obtaining stable riding with acceptable lateral railhead forces with its rigid-frame electric locomotives of the 2-B-2, 2-C-2, 1-D-1 and 2-D-2 wheel arrangements.

The 1937 article was not long before Blunt had moved to the next stage, which was his “lever” system, first used, I think, on the UP FEF2 4-8-4. I still haven't found the RA or RME article on this That I think exists, but it wa salso described in the pertinent patent.
US2230209A 19400302 Alco Lever System.pdf

Cheers,
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