Aarne-I'm not aware of how long you've been president of the Steam Railroading Institute, but I will always remember an editorial you had in Trains magazine years ago, about sustainable steam. Sustainable in the sense of having a plan for the next overhaul, etc...while there may have been other similar articles in that timeframe, for me, that article was the first I'd ever seen that got me (and no doubt others) thinking about the big-picture, long-term aspects of keeping steam running.

Kudos to you, and best wishes!

Greetings:
Aarne, with all due respect, 1225 has a bar frame. Plate frames are what they use in England, rather thin pieces of plate steel, but solid from the bottom of the pedestals (which they call horn blocks?) to the top of the frame above the driving boxes.
Plate frames are light and easily made. Bar frames are made of bar stock and quite heavy. The one piece cast steel frames as made by General Steel Castings (see Loco. Cyc.) are the heaviest and strongest and the least prone to cracking, and yes, the most difficult to work around or under.
J.David

I knew as soon as I entered that, someone would spot it. I'd been reading a British steam book and was under the influence of Stanier Black Fives. The frame on the 1225 is made of six major castings bolted together.

Aarne

Who is FMW Solutions? I take it this is an alliance of some existing key players.

We know what you meant, Aarne.

Optical or better metrology would be used in any modern frame-geometry work -- although I would listen attentively to Kelly Anderson and others here who might disagree for 'reasons given'.

Yes, you would adjust the wedges and shoes to give the correct rod distance between driver-axle centers. 1225 of course doesn't have roller rods, so this is somewhat less critical. As an interesting aside, I remember at least one case where a locomotive actually shed shoes and wedges and still operated just fine with the 'other' drivers contributing the tractive effort... something I would not have believed possible until someone pointed out the physics involved...

The issue of roller rods is interesting precisely because they can't work, any more than a bunblebee can fly. Clearance in those bearings was about 2 thou, and they were seated in bronze eyes (among other resaons) to prevent shocking them. Chapelon studied this and came to the somewhat unnerving conclusion that lateral bowing of the thin-section Timken rods was regularly occurring, at high speed and communicating great thrust force; he thought that a high-speed camera like the one used on the C&NW E-4 in the 1938 AAR testing would clearly establish this.

My understanding was that the 'datum' for driver spacing in the frame (whether cast or bar) is made by grinding the front pedestal faces. The shoes are then fine-tuned as needed to produce precise spacing (these being the thrust faces that actually move the locomotive and train). The Franklin wedges and their shoes are adjustable, to keep correct contact so the suspension can work, and while the actual rear faces of the pedestals need to be properly shaped, their dimension relative to the front faces is less critical.

Naturally you do all the necessary grinding with the pedestal ties installed and their bolts torqued to spec, just as you'd use a cylinder-head plate when honing bores.

My understanding is that FMW Solutions is the 'steam consulting' division of Davidson Ward's CSR/SRI.

It would appear that Ward has learned quite a bit about how to do consulting effectively in this field, even though his formal education was in architecture. Certainly many of us came to 'steam' as more of a hobby than a profession, so if in fact FMW Solutions is doing "the right stuff" I have no reason to question some speed bumps like Project 130 that are now solidly in the past.

On the side rods, the slop fresh out of the shop is generally about the same for plain bearings and for roller bearings, at about 1/32” on each crankpin. I understand that the bronze bushings around roller bearings are made with an oval hole, snug up and down, with .030 slop horizontally. This allows for slight variations in axle the rod tram and allows for the rods going off level to the frame due to variations in track elevation. Note that the bronze bushings around roller bearings in rods shouldn’t see much wear due to not having to run against a constantly moving crankpin.

Between the axles and the frame, plain bearing engines have more slop, with .010 to .015 slop between the box and the shoe and the properly adjusted wedge, plus roughly 1/32” slop between the box and the axle (though that dimension is widely variable, depending on shop practice).

I believe that roller bearing boxes only have the slop between the box and the shoe and wedge (and some have no wedge at all, just two shoes, very precisely made), with little or no slop between the box and the axle.

Back in the day, setting up the tram was done with very simple tools, string lines, plumb bobs, squares, and calipers, depending a lot on the patience of the machinist doing the setting up. Obviously, this works as the vast majority of engines ran successfully, though it is prone to errors creeping in. Variations on these methods are what I used throughout my career, and the engines thus set up ran well.

One can certainly use transits and the like, though I understand that the equipment needed is very expensive. Perhaps the results are more precise, but I have no experience with the techniques.

One of the later technologies is to have the frame 3D laser scanned, with can produce a virtual 3D model of the frame inside your computer. This model will have every detail of the frame displayed, warts, dirt and all, so careful prep work is needed. Really, all of the frame restoration should be completed before employing the laser scanner, so what is modeled is the repaired frame, ready for laying out the shoes and wedges. I wonder if the level of precision that laser scanning allows would obscure the forest for the trees, with a potentially overwhelming display of just how imprecise frames can be, while a lot of that dimensional variation doesn’t matter to the success of the job, and wouldn’t be noticed when following the traditional methods.

Regarding errors in quarter and throw on the crankpins, engines can tolerate larger variations in quarter between neighboring drivers and then they can in variations in throw. I have always been impressed at just how much variation in quarter and throw there is in supposedly match sets of drivers under a given locomotive. I understand that mainline locomotives were prone to having driver sets mixed and matched through various shoppings, but one would think that all of these wheel sets would have been in a quartering machine at some point, and that all of these quartering machines would be set to the same accurate 90 degree angle. Not so! Errors of an 1/8” in quarter are fairly common, and errors of 3/16” are not unheard of, on engines that have been successfully running for decades. Go figure.

Something to remember is this: Errors in things like quarter are 'hard' -- clearance against clearance as the assembly rotates. Errors where one side of the rod is against steam pressure or thrust are elastic -- they may overcompress the steam a bit around FDC/BDC but that is normally not a critical issue as far as bearings would be concerned.

Put water in there to hydrolock and the situation becomes dramatically different, of course...

Wow! Airborne! Looks amazing.

Thanks for the UPdate.

Looking forward to watching the progress.

Video walkthrough of the running gear work occurring on Pere Marquette 1225.

Link: https://youtu.be/K7UDgfPfRtg

Very nicely done! It is exciting to see progress on any locomotive and the steps described are quite familiar. I hope you run into no surprises............mld

Agree the video was very well done and educational, if one can remember how much goes into maintaining a locomotive. Not sure how many people can follow how stress works and where it comes out from worn spring rigging or boiler mounts, or sloppy running gear in general. And how much work goes into correcting it all. There is so much involved in keeping a locomotive running well. So glad to see her getting the attention she needs. No "plug and play" with steam. Congrats to #1225 crews.

Can't wait to see the work that goes into the ex C&NW #175 as well. Regards, John.

A part of me wants to ask if it might be possible to ever bring the 3 berkshires together for a meetup of some kind


However, another part of me is telling me to knock it off with the foamer dreams lmao