The weird thing is that the Allegheny is not THAT more ‘extreme’ than 1218 (which we will see run again), and really less overkill than the Big Boy. It’s just not compelling enough in any aspect to get the necessary funding in all the necessary ways, perticularly without an established tradition or support infrastructure. I don’t hesitate for a moment in noting that a CSX ‘steam program’ would be far better off commencing with 490, not a 1600 … or by sticking a broken dish and some disco color on that Reading 4-8-4 that’s been stranded in the Pacific Northwest… ;-}
A more viable option would be N&W Y6a 2156, even though I have heard it is difficult to get engines out of St.Louis. I do recall a recent report about 2156, but so far it has proved to be crossed wires and empty rumor. Very disappointing. As to 1218, I expect the move toward restoration to begin once 611 is “settled” in excursion service, which may be only a few months after she returns to operation, considering what time of the year she is fired up. And, I fully expect some of 611’s earnings in excursion service to be used in the restoration of 1218. lois
Well of course 1218’s coming back, or at least it will if that guy (who’s name I won’t mention) ranting and raving in the “611-4014” thread has anything to say about it.
Hey, he did everything else he said he was going to do.
For the moment, I’d like to discuss the benefit of the use of roller bearings. Started on the N&W with the first A, 1200, then from the A’s to the Y6’s (which like the A’s, were equipped with roller bearings on the axles of engine and tender.) Finally to the J’s, which got the full roller bearing treatment, from wheel journals to valve gear to side rods. It is like if they found a place on the J’s running gear to apply roller bearings, then they were used. And as we know, the last five A’s (1238-1242) were equipped with roller bearing side rods. lois
However, I will note one benefit of using roller bearings, and I’m certain you can name others. When the 611 was restored for excursion service in 1981-2, when her running gear was inspected, almost no wear was found, due to roller bearings. However, the bearings themselves were found to be in very good shape, barring only one or two with had minor damage. This is surprising considering the fact that 611 had sat outside for over 20 years. lois
One consideration with roller bearings is the type of lubrication – oil or grease. A principal issue Wardale reports for oil-lubricated (Timken) bearings is that there’s leakage past the seals, which can eventually get to the driver treads. Lube leakage from roller rods is, of course, well documented. There’s been some interest in applying AAR M-942-spec grease lubrication to rod bearings, and of course there’s no reason it can’t be adapted to driving boxes… with care.
There are solid-bearing alternatives to rollers on rods, mostly involving the sort of geometry used on the late UP 4-8-4s, and modern materials, especially hard coatings and better methods of tribology. In some cases it may make sense to use these instead of new purpose-manufactured thin rollers at the necessary cost for small-volume production. (It remains to be seen how much Timken will quote new bearing production… but it won’t be long ;-} )
However, regarding 611’s upcoming restoration, the bearings were tested at the museum back in May and were found to be in good shape. I suspect that there will not be any changes when the locomotive is disassembled for restoration, as with the 611 being kept under cover with regular lubrication and occasional movement. The only issue I have heard of being with the running gear is the needed replacement of the engine truck wheels, but that is an leftover issue from 1994 that the steam shop was unable to do at the time. At present, design and other plans are in progress for the rebuild of the engine truck, so in a way, the initial part of the restoration has already begun. lois
Regarding 611 there would be no changes to the bearings. As far as I know they’re in fine shape, and special attention has been paid to the two things that ‘kill’ roller bearings on stored locomotives: leaving them too long with weight on them, and exposing them to fretting levels of vibration without periodically renewing the lube film. I feel quite certain that the periodic moving of the locomotive while at VMT has ensured neither situation has occurred.
If at some point the EPA regs are changed so that total-loss lubrication is no longer possible on steam locomotives, it would be a simple thing to change the lubrication system – either by using pressure and return lines, or converting the seals and reservoirs on the existing bearings to work with a good and appropriate modern grade of grease.
It is my opinion that anything involving the engine-truck wheels need not affect the roller bearings. But of all the times it’s easiest to do something with the bearings… it’s when the wheelsets are out of the locomotive and the wheels are pressed off the axles… ;-} At the very least, I’d do a really careful mapping of the inner and outer race faces, and perhaps the surface of the rolls, and perform some reasonably high-resolution NDT on the underlying metal. It will be a very long time before that becomes easy to do again…
I’d post this over on RyPN, too, where there are people familiar with the care and feeding of roller bearings during overhaul.
I hope to hear some news regarding the redesign of 611’s engine truck. All I know at this point is that they will be working within the original truck frame. Why they are not just replacing the wheels I don’t know, unless there was some additional necessities that came up. lois
Let us know stat if the idea is to reduce lateral stiffness, or change lateral compliance.
This would be a very logical change if the engine’s speed is to be kept below 40 mph, as it would reduce the effective rigid wheelbase and allow the locomotive to track ‘diesel-grade’ alignment a bit more easily. I would want to make very sure, though, that the change was fully reversible, and that all stages of the modifications were fully documented (and all original parts kept intact, or taken out and retained without modification)
Below 40 mph? I don’t quite know about that. I know it has been discussed here and elsewhere whether NS is sticking to the 40 mph speed limit. And on the ride behind 630 nearly a year ago, I seemed to remember at one point going a bit over 40. But 611 is a high-speed passenger engine, and it would seem unfair to her to not allow her a sprint or two, if only on ferry runs without passengers. Her historic status and her age (she will be 64 in May) shouldn’t limit her from the occasional high speed run. A few rules may be considered for these runs: 1. They are made without passengers. 2. The crew including an engineer that has run her in high speed operation. 3. The speed not to exceed posted track speed, though she may be limited to 5-10 mph below track speed. Since most track on NS (not including former Conrail lines) seems to have a 60 mph speed limit, that may be an additional limitation. But before the 1986 wreck, she seemed to run regularly at 60 mph, and that might not be an issue for her. lois
No reason 611 couldn’t run up to 60mph. As I understand it the 40mph speed limit was a reaction (knee-jerk or otherwise) to the 1986 Dismal Swamp wreck, even though the speed and train handling had nothing to do with the wreck, one of the passenger cars “picked” a switch. I imagine insurance coverage may have had something to do with the speed limit as well.
On the other hand, two reasons I can think of to limit the speed to 40mph would be to save wear and tear on the locomotive, and because riders want the ride to last.
I had not long ago received the report on the May 1986 wreck, and hope to discuss it in detail with you later. But since there seems to be a limitation of interest on discussing wrecks, I will note only a few points. The cause seems to be heat-damaged rail and the failure of maintenance-of-way crews to properly manage track in this condition. The car that picked the switch was a former N&W P3 “Powhatan Arrow” coach, which led several of its P3 sisters and other coaches off the tracks. Three Southern heavyweight cars overturned, and they were damaged so badly they were set aside for scrap. These included a coach, open-window car “Missionary Ridge” (then lettered for N&W) and commissary/former baggage “Queen and Crescent Club”. All former Southern heavyweight cars were retired at this point, as it was considered too difficult to retrofit them with the tightlock couplers that were now required. It is felt that the lack of tightlock couplers was the reason why the named three cars had separated and overturned. lois
Well thanks for that information Lois! I don’t understand the non-interest in wrecks, there’s always something to be learned from wreck stories, especially the “why’s-and-wherefores” and how you keep them from happening again.
Thanks again!
I took the amount of interest from the number of replies, which were very few. Perhaps there was more interest in the subject than I thought. lois
Juniatha has not posted on this thread yet, which I suppose there has not yet been a subject that has piqued her interest. However, I did post the roller bearing issue over on RYPN, and learned that the issue with 611 is with roller bearings that are no longer being produced. A bit of work has to be done to retrofit the new bearings where they need to be replaced, which is on the engine truck. As this truck guides the locomotive into curves, there is some side-to-side stress as wheels on one side are “leaned into” when going round a curve. Being that Timken is still in operation, I expect them to be called upon in the design process of the engine truck and retrofitting the new bearings to the original truck frame. lois
I will however introduce a new subject. The J, being the most powerful 4-8-4, was originally designed with 275 psi boiler pressure with a similar sized boiler to that used on the Y6 class 2-8-8-2. One J, 602, was fitted with a booster but this was later removed because of problems. After tests, the boiler pressure on the J’s was raised to 300 psi. The tractive effort at 300 psi was estimated at 80,000 lbs. though it was possibly somewhat higher. How much higher I don’t know, as it depends on the formula for calculating tractive effort. A old formula I found for calculating tractive effort gave the J around 84,840 lbs. I found formulas for calculating boiler and cylinder HP as well. The figures for the J came out the same:4636. I am aware that this may be different than drawbar HP, which in the J was estimated at 5100 but may be as high as 5400. Of course, the same estimation gave the A a drawbar HP of 6300 as well as the tractive effort figure of around 112,000 lbs. I do understand that in the cylinder the steam has a tendency to condensate, being at a lower temperature than in the boiler. It is for this reason that superheaters were developed, to maintain the high temperature of the steam so it would retain its power. I would expect the figures for boiler and cylinder HP to be different, but in my figures on the J, they turned out to be the same. What do you think about this? lois
The formulae are for indicated horsepower, ihp, and as you might suspect you can get more ‘exact’ data by integrating the result from a physical steam-engine indicator card, first for one ‘side’ of the cylinder, then for the ‘other’. Usually, however, ihp is much higher than drawbar horsepower, dbhp, which ought to be an ‘actual’ number measured by a dynamometer car or test plant, net of all machine losses. Aren’t there indicator cards extant for a number of J tests?
Note that one ‘ringer’ in the formulae is an assumption for boiler-pressure drop. If a locomotive has steam-chest pressure gauges (as I believe 611 does) you would use these readings as the ‘pressure’ input for the duration of admission
There are two reasons why steam condenses in the cylinders. One is partially avoidable, the other an inevitable consequence of work being extracted from the steam (to move the locomotive and train).
The first is commonly called ‘wall condensation’ and it occurs when water molecules in the steam preferentially adhere to the exposed surfaces of the cylnder, heads, and piston/rod. If the temperature of the inner cylinder wall is lower than that of the steam – which is usually the case – the steam may preferentially condense onto it; there is also a physical ‘wetting’ effect. Both cause an effective phase change and concomitant volume decrease, and this relieves some of the effective piston thrust. One way to get around this is to heat the ‘cold’ surfaces, which limits the range of thermal cycling at the walls; another is, as noted, to use higher superheat in the steam to keep its critical temperature above the condensation point even at high admission pressure. Theoretically if you heat the wall metal above the critical temperature, little or no steam will actually change phase during expansion – this was the point of Chapelon’s passing all the main steam to the
As to surviving data on J tests, I do know there remains some documents in the N&WHS archives. There is a list of documents for the J listed on the N&WHS website, I will have to examine this list and see if there is anything regarding this particular subject. lois
I will concede that the J appears to have been an excellent performer. I also get the impression that it falls into the same category as NYC’s Niagaras, it was too big and too powerful for the service in which it was actually used.