N&W Y7

Since the N&W “cast” their drivers, maybe you could explain yourself.

A couple of Great Northern R-1 2-8-8-2 photos for Y7 and R-2 comparison purposes…

Image result for great northern steam freight train horseshoe

Image result for great northern r-1 class

Design of the Y7 class was apparently underway when the project was terminated. The drive wheel drawings can be viewed at the N&W Historical Society website.

Main Driving Wheel:

http://www.nwhs.org/archivesdb/detail.php?ID=47406

Front & Back Driving Wheel:

http://www.nwhs.org/archivesdb/detail.php?ID=47419

Intermediate Driving Wheel:

http://www.nwhs.org/archivesdb/detail.php?ID=47423

These drawings are dated March and April, 1937.

Cast disc driver centers (as in Boxpok or LFM) as opposed to ‘traditional’ N&W spoke.

N&W went further, and did better, with 70" spoke even on very fast and high-powered locomotives (classes J and A) up to the end of steam. In part on the J class, this is because Glaze’s balancing plan distributed the balance masses in a way that spoke driver centers could accommodate.

Other roads (the T&P 2-10-4s being a very good example) needed to go to a cast disc for the main driver to allow the desired high-speed balancing; it’s hard to see it on 610 but it is there, and necessary. What I am wondering is whether the loads on the Y7 running gear would have made the use of some form of disc cast driver for the main either desirable or necessary – or made the use of webbing (as in Web-Spoke) or different rim construction (as in SCOA-P) to reduce strains between spokes and rim.

The detail work on the Y7 running gear stopped just about the time advanced balancing for freight locomotives became an important design priority (and a means of converting ‘dogs’ into relatively good performers). It is not surprising that the existing wheel drawings (which of course N&W could easily cast without having to pay any royalties) do not reflect what might become optimal with the engines built and used in fast heavy service to their design potential.

I have to wonder whether lightweight rods and better main construction (with room for necessary balance mass) might have helped the K3s before N&W wrote them off…

It is too bad the Y7 never got built. It would have been something!

To their credit, the story of the Y7 shows that the N&W didn’t build locomotives for which no business/operating need existed. Other roads built steam locomotives that were answers to questions nobody asked.

In my opinion, there was a perfectly good operating need before the Government got onto the wacky train-length-reduction kick, and a perfectly good operating and business need afterward. It was simply misfortune that the Y7 development happened to fall into that particular timeframe, and that afterward the combination of good A class power and the improvements to the compound articulateds handled the service as required ‘well enough’ that development of a whole new class wasn’t justified then.

Yes, of course, it must be based on economic need, but it still would have been something to see what the Wizards of Roanoke would have been able to conjure up in a live Y7.

Great Northern had line drawings done of enormous 2-6-6-4 and 4-6-6-4 units with 73 inch drivers and 133 sf of grate area.

The GN also strongly considered following up their R-2 locomotives with a massive 2-8-8-4 with 69 inch drivers and 180 sf of grate area. This engine would have rivaled and may have surpassed Big Boy in size, but still with a rigid wheelbase of just 18 feet, no longer than the rigid wheelbase of their O-8 Mikados with 69 inch drivers.

Of course, history shows that none of these were built either, but that doesn’t mean they wouldn’t have been amazing machines.

In my mind, the Y7 would have been able to haul dead freight on flatter divisions more economically than the A (via longer train lengths). It would have been able to match or exceed the Y5/Y6 types in hauling heavy tonnage up mountain grades, although it could not match the efficiency of the compounds. I also question whether the Y7 would fit everywhere the Y5/Y6 could go.

The train-length reduction issue was based on state statutes (usually 70 cars) which were stricken by the Supreme Court as an unconstitutional state regulation of interstate commerce.

If not for deisels, Y7s would have been built.

I remember Ed King describing it differently in his book on the A; he said there was some pending federal regulation (through the ICC) of train length (to something like 83 cars) and that was the specific thing cited for the suspension of the Y7 development. (I don’t have my copy of the book accessible; someone who has it can probably quote the relevant sentences.)

If you have the detailed case history for the situation you describe, including cites, I’d greatly appreciate it.

That is the way I remember it.

One challenge for the N&W nearing the end of steam was that it was becoming harder to get appliances that were needed; since the lubricators, dynamos, injectors, feedwater heaters, ect, ect. were outsourced and built by Nathan, Franklin, Elesco, (And so on…)

As almost every other railroad had done away with steam, many of these companies had gone under and the N&W could not get the things that they did not build themselves. Probably one of the many reasons a large order of “home-built” Y7’s was canceled.

I’ve linked to the Supreme Court ruling that struck down State-mandated train length restrictions:

https://supreme.justia.com/cases/federal/us/325/761/case.html

It is a more than a bit convoluted in it’s wording (lawyers…) but it does go into the prior legal history of such State legislation…

I suppose that the Ruling does not necessarily mean that there wasn’t federal legislation about train length proposed in the late 30’s but for that to be the overriding factor in the railroads decision we would have to know whether or not the States that N&W served had such restrictions on the books during that period…

That may not be the case…

Keep in mind that the railroad did not own a single diesel-electric locomotive until 1955. They built new steam locomotives right up until 1953 (an 0-8-0 switcher) with their last new build road locomotive, a Y6B, being erected in 1952.

Post-World War 2 the railway stayed committed to steam traction much longer than most of the rest of the industry but focused on improving the A class 2-6-6-4s and the ultimate version of the Y series compound 2-8-8-2s.

N&W management still showed some interest in continuing with coal fueled external combustion power via the Jawn Henry Steam Turbine-electric project after the end of conventional steam locomotive production. However I suspect that by the time they placed big orders with Alco and EMD the higher-ups started to realize that steam really was on it’s way out…

The state mandated train length restrictions that were the big factor in cancelling the Y7 class were invalidated by the US Supreme Court at the end of the war so the company could have gone ahead with the design. It would seem that they felt that improvements to the A and Y6b classes fit their operational requirements…

Rather obviously Southern Pacific Co v. Arizona has little if any bearing on the N&W’s design decisions. I found it interesting that SP had evidently accorded with the Arizona 70-car limit from 1912 all the way through to 1940 before ‘testing’ it (along with the accompanying passenger-car train limit) and that the Government thought it desirable to issue an order suspending any train-length limits in 1942.

However, footnote 1 in this case does clearly establish what we needed: there was indeed Federal legislation, 75th Congress S.69, a McCarran bill to restrict all freight trains to 70 (apparently not 83) cars. This was apparently approved by the Senate but died when sent to the House (I have not found the record of its history there.)

This legislation is the ‘smoking gun’ that spelled the end of Y7 development. Had Y7 development proceeded as ‘speculation’, it might have been complete enough to pass WPA review for construction for ‘wartime’ service as a high-powered single-unit engine, same as the PRR Q2, and it might be interesting to think about how a cohort of these engines would have been used in N&W service through the period of experimentation and improvement on the Y-class compounds.

I encourage people with the proper access (I apparently can’t get the Congressional archive site to load with my browser-level “security options”) to provide a link or text for S.69 and any House counterpart legislation that would supposedly assist ‘full employment’ during the second Depression downturn. (There is co

It’s my belief that the merger talks with the VGN was another major factor in N&W giving up on steam. Operational economy pretty much dictates that locomotives be used systemwide and the VGN didn’t have much support for steam at the time. The merger also meant the demise of VGN’s electrification despite having the most modern electric locomotive fleet (two classes after WW2).

The demise of the VGN electrification was caused by the establishment of directional running as a result of the N&W/VGN merger. The electrification became a one-way operation which killed any efficiencies.

Which leads me to ask a slightly off topic question:

N&W continued limited steam operations for a couple of years after the merger but the Virginian had completely dieselised prior to it.

Did N&W ever operate steam locomotives on the former Virginian trackage?