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N&W's Y7 has been pretty well covered by Pond and by Jeffries; as mentioned, the second edition of Jeffries' book should be available within days. Jeffries also has a side elevation of the Y7 compiled from available shop drawings. It would have fit on N&W's standard 115' turntables. Weights were not figured, but with N&W's usage of the Cooper E-72 axle loading gauge, weight on drivers would have been around 576,000 pounds, with probably another 30,000 on the lead truck and 50,000 on the trailer, for a total of 656,000 pounds. This would not have made it the heaviest of 2-8-8-2s. C. E. Pond says that the boiler pressure would have been set at 285 pounds, but if actually constructed it would have probably been at N&W's then standard for 2-8-8-2s of 300. When the engine was being designed, the first class A 2-6-6-4s were just hitting the road, as were the first Y6 compound 2-8-8-2s. The railroad didn't have much experience with the As at the time; it knew what performance to expect from the Y6 because of the success (performance, not maintenance because of the bar frames) of the Y4a (Y5) built in 1930. The shelving of the Y7 because of the proposed legislation makes a good story, but I think that the N&W found out a couple of things about the class A and the Y6 that helped put the Y7 to sleep. First, the A produced more DBHP at high speed than anything else in the world in 1936. The A also burned coal like nothing else N&W had ever seen in so doing; N&W wasn't troubled by this fact because of the results that came out of the tender drawbar. But they had to realize that a simple 2-8-8-2 with cylinders 2" larger was going to be even more of a coal eater. Would the results at the drawbar be worth it? Evidently they didn't think so. The compound Y6 would have been much more economical in the mountains than the Y7, and the A, on the flat districts, would handle as much train as the railroad could be comfortable with (getting in and out of yards, and such). In short the Y7 was going to be a "niche" engine. The only districts where high speed was hard on the Y6 were the Bristol Line west of Radford and the Shenandoah Division north of Shenandoah; these were, speedwise, the most demanding districts for the Y6, but they caused less trouble in those areas than might be expected. Add to these factors, the Y7 was going to use a trailing truck booster to bump its low-speed tractive effort up into the Y6's class. This adds a high-cost, high-maintenance item of jewelry to the engine. It might have been an advantage over the Y6 of 1936 which had to be shifted from simple to compound at about 4-5 MPH, but not over the later Y6 as modified with the improved intercepting valves which could be operated simple up to 10 MPH with additional help from the booster valve above 10 MPH. So it probably was for the best that the Y7 was never built, but put me on the list of those who would love to have seen it. Oh, and Futuremodal - you have suggested that post-dieselization the railroads ROI diminished by half, but can't show any concrete correlation between that fact and the costs of dieselization. I asked for names of railroads whose bankruptcies could directly be blamed on dieselization and none are forthcoming. I suggest to you that the post-dieselization ERA ROI would have been much less than half, if the railroads had found it necessary to operate with steam Old Timer
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