Steam & Excursion > Interesting updates to rebuilding decisions & steam locos

Refer to subjects related to post dated:
4/03/24, 17:33 hrs,  "2926 in steam event Oct 28"

W...
 



Edited 3 time(s). Last edit at 04/12/24 03:32 by wcamp1472.

That's far too cryptic for any of us to understand and why'd you have to edit it 3 times?

Out 

His post and he can do what he wants.

Ok...
A week ago I had added comments to the cited post, under the 
relevant date.
A reader subsequently asked a relevant question, seeking 
clarification to the post, of that original date.

There is no way that the interested reader would have known that I had 
added more current information --- that was the reader was seeking..

I recently responded in a detailed reply.
I was posting this date reference, for those that might have wondered 
about the same things as the original person who posted the question.
However, there was no way for readers to know that more current discussions 
had been added into the original  posting, still listed under the earlier date.

All you had to do, was to go to that post & date...scan down to the most
recent explanation, and get brought up-to-date.  The current reference to
the updated information, makes it easier for those that might have an 
interest in the matter, to find & get the benefit of the more current entry.

I enter the preliminary post title, then post it...for added details and accuracy 
I may add more details; however,  since I can't temporarily close a typed entry,
and then return to it, the only way to save preliminary information is to 'post it',
as a step in the editing process. 

In other, more advanced document software, you can type preliminary data,
save it, then refine or add additional data, then post the final, updated document.  
On this site's limited software there is no way to update or add additional data,
without losing the whole attempted draft of the post/message..

Talk to the powers that be of this site to convince them to use a better software.
Also, the 'spell check' feature needs a way to be 'turned off' ,  some technical terms get 
over-ridden with really stupid substitutions.

So, yes, I will type, post to save it, add more data, post the update, 
add additional data, and post that.  Sometimes, during my composition I 
will want to refer to a relevant T/O post, or other data on an entirely different
web site and in order to view the reference,  I can only save what's been typed
by posting the draft, incomplete document .

Then I'll get the update information, and go back into the posted, draft document,
and add the more current data.  

If there were a 'draft' function in this software, that would make it possible
to post only the finalized, finished post.
Hey, it ain't my site.  You work with the tools of this site.

If I compose a document in Word, then post the Word document, all
of the paragraph edits are lost when transferred to the T/O site, and the
reader is confronted with a document that makes no sense,
lost in a sold block word noise.

Sorry to have confused you with my added edits..
If you don't have an interest, skip over the posted reference information,
and read on....
Duh !

​W.



Edited 2 time(s). Last edit at 04/12/24 09:02 by wcamp1472.

Uh, there's nothing on the 2926 website about an October activity, nothing on RPYN, and 
I missed thje reference to the previous post, as I said "cryptic".

Out 

callum_out Wrote:
-------------------------------------------------------
> Uh, there's nothing on the 2926 website about an
> October activity, nothing on RPYN, and 
> I missed thje reference to the previous post, as I
> said "cryptic".
>
> Out 

Wes did NOT say it was on the "2926 website"! The specific thread about the 2926 steam up event in October, was posted here on TO, on April 2, and is still active, just one day below. Look for it.

Link to thread under discussion:
https://www.trainorders.com/discussion/read.php?10,5842716

Posted from iPhone

Thanks for the link Kevin, much appreciated, guess I'm a bit too dense to grasp Wes's
original title.

Out 

tomstp Wrote:
-------------------------------------------------------
> His post and he can do what he wants.


X2

Keep posting your detailed knowledge Wes, I've learned a lot about steam details from you I wasn't even looking for, sometimes it's over my old head at first, but it sinks in later!

The science of Steam Locomotive technology is far more detailed than I ever thought of or imagined, and you have so eloquently pointed out in your articles how it has to be done the right way, or else trouble will rear its ugly (and expensive now days) head!

Jim Baker
Riverside, CA

Likewise to both Hot Water and Wes and alon g with Doyle, easily the most knowledable steam folks on the planet!  I have learned a lot.  manhy thanks and keep well!

As you have seen, "trouble rears it's ugly head", even when you do 
everything the "right way"...

I've found that the more 'thorough' a tear-down and rebuild,
the greater opportunity for mistakes during re-assembly,
land often results in tiny errors that cumulatively creep into each step.
So that when things heat-up, and expansion changes critical dimensions 
setting the path where design weaknesses yeilds breakdowns.

As an example, totally disassembly of a functionable CrossCompund 
air compressor might later suffer an unusual broken piston ring,
or a delicate pierce in the auto-reversing valve mechanism seizes,
or breaks-down.

It may well be, that there is a speciic 'secret step' that is omitted during 
a reassembly of the compressor.  The step might be a crucial secret to success
that existed only as a verbal instruction, historically handed down from tech to 'student'.
Those many thousands of secret steps, have been lost to the ages.

So, the opportunity to 'improve' the rebuilding process, only winds-up 
creating a myriad of future traps, that lie in the future operation of the tinkered-with
functioning assembly, by a curiosity-seeker, trying to learn  "how this thing works",
by tearing it down.

So, returning a steamer to current-day service is art, more than reassembly skills.
An example is: the complex sheet-copper, factotry-stamped cylinder head 
gaskets at the 4 locations between the steam cylinders of the air compressors 
and their mating-heads.  During disassembly, folks will take a screw-driver,
as a lever to separate the head from the cylinder casting --- only to have the
screw driver permanently damage  the irreplaceable, copper head-gasket.

That often results in an 'ooops' the moment.  Taking things apart sets-up
the opportunity for innumerable 'ooops-moments',  lurking down the road ahead.  

However, there are many times where extensive rusting or corrosion has set-in.
and disassembly and re-machining is mandatory; but, try to limit those situations,
to where a simple bench test, using  compressed-air could reveal a fully-functional 
air compressor --- who's operational life could be decades of reliable service,
in multiple future excursions. There are many 'secret steps' that were taken,
during that last re-build, and who's secrets have been lost to the ages.

The saving-grace is that with today's tools, new materials, and methods can be
substituted for the 'old-way'.  A common improvement is the use of high-temperature 
Teflon-like rope-gasketing materials for sealing piston rods, etc.
Or, of using today's graphite-impregnated brass bushings, in place of the older,
plain brass bushings.   Permanently-lubricsted brass bushings can last many
lifetimes of use, compared  to the old-style, plain brass bushings.

So, where we have better materials, it may make sense to put the new,
improved materials to work.  And maybe substituting todays'  "gasket-in-a-tube",
for the old, copper gaskets, might be a better option. And using todays'
far-superior welding techniques and materials is a clear advantage, over the 
old-way!.

Be wise, and learn as you go.  Could there be a better way, today?
which might substitute for the old, lost secrets of the past. 

Where it makes sense, upgrading axle bearings for roller bearings 
is ALWAYS a better way to go, if funding is possible. Most generally 
applied to axles other than driver axles, on the older locos.

However, upgrading 12" diameter driver axles is a much more complex 
process, since the driver-center's original axle hole has been permanently 
enlarged & distorted, so that reassembly without a newly-bored axle-hole,
results in a low-force axle-fit.  If you tried to reassemble the two original
components.  The previously stretched axle-hole has lost it's original
clamping-force; reassembled pressures are much lower with a stretched
axle hole, when reassembled.  So, you need a larger diameter axle-hole
in the driver center.

The future PRR T-1 project has the advantage of making complete, new
driver-sets: new wheels and axles, using today's, newly manufactured,
12" diameter axles and roller bearings. 120MPH, here we come!
Onward and upward!

W.

( Even in today's practice,where new freight car wheels are pressed onto 
   re-qualified axles.  The wheel press has pressure recording devices at each wheel
    [ the traces used to be made on paper, now most are digitized and stored
     permanently] 

   The paper traces, revealing increasing hydraulic pressures, often were text-book
    smooth. You wanted a 'ramp', typically 45-degrees, the entire distance of the
   axle hole in the wheel.  Often derailment investigators will want to examine the
   specific axle-press recorded pressures, and every axle has its own separate
    trace-recirds on file for wheels pressed.  Wheel press contractors are expected 
    to catch and reject any out-of-spec, improper pressure traces.

    Improper, and rejected, wheel-fits either 'flattened' before the complete fit, 
     or they spiked-higher, before reaching the raised, limit ring of the axle.
     An ideal press record will have the pressure-slope hit maximum, where 
     the wheel reaches the raised-stop on the axle.
     I haven't seen what the axle traces look like for steam loco drivers.

     It's interesting seeing the adoption of the BoxPok [ box-spoke] driver centers.
     These cast steel driver centers had stronger-designed support at two key areas, 
      and were superior and lighter than conventional 'wagon-wheel', spoked drivers.
      The two key areas of improved, more uniform clamping pressures were at the
      axle-holes and the crankpin holes.   On rebuilt and 'modernized' steamers 
     it was common to apply BoxPok drivers at the main driver only, retaining the
     spoked, original driver centers at the other axles.  The piston forces are greatest 
     at the crankpins and axles of the Main Driver axle.
      
      In both styles of driver-centers, the counterweight cavities were cast hollow
      and molten lead was poured into the wheel counterweight cavities.  
      In most cases the cavities are only partially filled with lead.
      The cavities were then covered with crescents of sheet-steel covering
      the counterweight cavities.
      
       In service, the melted lead was pounded into white dust, but still carried 
      the same weight.  The white powder in the driver counterweight cavities was
     most commonly revealed at the scrap yards,  where the steam locos were cut-up).
 



Edited 4 time(s). Last edit at 04/18/24 11:03 by wcamp1472.

The more time I spend with steam the more I am in complete awe of the degree of engineering that went on, both calculated and empirical, for just about everything.   As I wade through Baldwin Standard Practice documents, coming across formulas and engineering constants that are inexplicable, all you know is that they apparently worked.

And there's a certain amound of "why is that bolt 1/2 - it could be smaller?" but you know they did that to 3/8" and somebody got killed.... so make it 1/2"