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The best articulated locomotive.

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Posted by CAZEPHYR on Tuesday, May 7, 2013 10:39 AM

All of our thoughts remind me of 1955 era when discussions like this were going on.   This subject will never end as long as we talk steam!

I got to see some of the best steam built and enjoyed seeing each of those in their own glory.  

 

CZ

 

And who can forget the Jawn Henry.  A short life but was very strong!


 

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Posted by Firelock76 on Tuesday, May 7, 2013 5:30 PM

Ah, N&W, the power and the glory.  Thanks for posting!

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Posted by GP40-2 on Tuesday, May 7, 2013 7:24 PM

Firelock76

Ah, N&W, the power and the glory.  Thanks for posting!

Except the most power was in the middle photograph, which was C&O. Smile, Wink & Grin

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Posted by Overmod on Tuesday, May 7, 2013 8:23 PM

GP40-2
Except the most power was in the middle photograph, which was C&O.

True.  

But backlit like that, it could as easily be Virginian... and N&W took over Virginian (albeit after steam had gone) ... so...   ;-}

[Leads me to wonder whether we could have a Godwin-style thread on here where every post takes a certain amount of steps before bringing up N&W... or perhaps other near 'n dear subjects like Amt....

No, on further brief contemplation.  No.

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Posted by rfpjohn on Tuesday, May 7, 2013 9:55 PM

I thought that all posts led to G5s's, eventually.

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Posted by Overmod on Wednesday, May 8, 2013 6:45 AM

rfpjohn

I thought that all posts led to G5s's, eventually.

And now this one has, too.

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Posted by CAZEPHYR on Wednesday, May 8, 2013 10:50 AM

Overmod

GP40-2
Except the most power was in the middle photograph, which was C&O.

True.  

But backlit like that, it could as easily be Virginian... and N&W took over Virginian (albeit after steam had gone) ... so...   ;-}

[Leads me to wonder whether we could have a Godwin-style thread on here where every post takes a certain amount of steps before bringing up N&W... or perhaps other near 'n dear subjects like Amt....

No, on further brief contemplation.  No.

No it was a C&O.  Both the H8 and the A class were super locomotives.

 

CZ

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Posted by Overmod on Wednesday, May 8, 2013 11:22 AM

CAZEPHYR
Both the H8 and the A class were super locomotives.

But so was the Virginian AG.

And it was lighter than the original 'scam' Alleghenies,and some references call it the model for the 1948 order of Alleghenies...

What ARE the visible differences between a H8 and an AG when  backlit so the lettering isn't visible?

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Posted by rfpjohn on Wednesday, May 8, 2013 7:00 PM

This response is nearly as slow as a Virginian 2-10-10-2. To Firelock76: Those handsome Eritrean 0-4-4-0t's were built by Ansaldo in Genova. This is according to the Gods of Wikapedia. I looked up a video of them on Youtube (for there were other things I should of been doing) and was surprised to see they are coal burners! Really expected oil, in that part of the world. And now to 54light54: Ok , those German 0-4-4-0t's are pretty cute, though I prefer the meter gauge ones to the 750mm jobs with the nose to nose cylinders. Something about that arrangement doesn't seem right! Of course, the key to any discussion about articulated locomotives is to remain flexible.

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Posted by rfpjohn on Wednesday, May 8, 2013 7:12 PM

My apologies to 54light15 for mislabeling you. Sometimes I have problems articulating.

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Posted by Overmod on Thursday, May 9, 2013 6:30 AM

rfpjohn

My apologies to 54light15 for mislabeling you. Sometimes I have problems articulating.

And I sometimes get my nose out of joint.  But when the discussion hinges on technical points, I think we can find a way for both to pull in step.

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Posted by rfpjohn on Thursday, May 9, 2013 1:36 PM

I guess I could make a comment about compounding the problem, but I feel that I could only present a strong argument for the first half. The second part would be much weaker and take up twice the space. Now we should have enough corn to produce ethanol!

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Posted by Overmod on Thursday, May 9, 2013 1:57 PM

rfpjohn

I guess I could make a comment about compounding the problem, but I feel that I could only present a strong argument for the first half. The second part would be much weaker and take up twice the space.

Except what happens when the front half isn't the first half?

In any case, the proven solution is a little moderated injection of new enthusiasm when the second half starts to flag.  Not too much, not too little, and in just the right phase.  The French have skill in such things, and not just in l'amour.

Now we should have enough corn to produce ethanol!

Now you know, in part, why I prefer my ethanol from grain...

Pity we're pone to making such awful puns.

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Posted by 54light15 on Thursday, May 9, 2013 4:33 PM

54Light54??? I resemble that remark! Nyuk,nyuk,nyuk! I've heard that the USA is the Saudi Arabia of corn. I think I see why. I can think of a better use for corn and that's Jack Daniels.

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Posted by Firelock76 on Thursday, May 9, 2013 6:33 PM

To rfpJohn:  Ah, Ansaldo!  I might have known!  They built a pretty hot fighter plane during the First World War as well, the A-1.  It was capable of 140 miles an hour when the average fighter did about 120 to 130.

The built some pretty good ships for that matter as well.

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Posted by rfpjohn on Thursday, May 9, 2013 8:11 PM

And, evidently a very durable 0-4-4-0T! In watching the video(s), whilst ignoring important chores, I noticed some of the Mallets had slide-valve low pressure units while others were equipped with piston valves. After market modification? I sort of doubt they could match fighter plane speeds, though down some of those grades they might come close for a short time! Should I be double spacing when referring to the low pressure units?

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Posted by Overmod on Friday, May 10, 2013 3:22 AM

rfpjohn
I noticed some of the Mallets had slide-valve low pressure units while others were equipped with piston valves. After market modification?

Just as a peripheral note:  There WERE 'aftermarket' conversion kits to change slide valves over to piston valves: these were called 'Universal' steam chests.  Essentially a whole piston valve and its porting in a box that could be bolted to the flange on the cylinder block.  If I were doing the designing, this would also involve increasing the effective throw of the valve gear, but I don't know if this was usually done (not my favorite design period!)

Port size and relative flow were limited, and the dead space was (necessarily, in most cases) greater.  But it nominally preserved investment in older cylinders and, again theoretically, allowed some standard-sized parts or components to be shared between more locomotives.

With widespread adoption of superheating (which makes lubrication of slide valves much more difficult, so engines built superheated would have piston valves, and if converted would get new cylinders) and generally larger locomotive sizes, most of the demand for Universals dried up relatively quickly.

I suspect in the case of the 0-4-4-0s you are seeing different construction practice as built, not a 'conversion' from slide to piston without changing out the cylinders.  (I wouldn't really consider changing the whole cylinder block from slide to piston an 'aftermarket' conversion in this sense, but wouldn't be surprised to find it happening as piston valves became more and more pervasive in practice.)

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Posted by rfpjohn on Friday, May 10, 2013 1:36 PM

It could be that the slide-valve/piston-valve engines in the video were from different orders. There were no visible numbers, but the wiki article I read mentioned three series. As for the Universal steam chests, the Southern Railway was a big user. I have heard that one undesirable feature of this steam chest was that, by necessity, the conversions were outside admission. This, of course, put high pressure against the valve packing, which was an invitation for leakage. In a book I have on the N.F.&D. there are pictures, before and after the second world war of a Light pacific 1226, class Ps. In the pre war shot, she has the Universal conversion. Post war finds her sporting a conventional piston valve cylinder block. I'm sure someone out there knows the real story, but I'm guessing that the Universal arrangement was found to be OK 'til a major shopping allowed the opportunity to upgrade to conventional piston valves.

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Posted by Overmod on Friday, May 10, 2013 4:02 PM

rfpjohn
I have heard that one undesirable feature of this steam chest was that, by necessity, the conversions were outside admission. This, of course, put high pressure against the valve packing, which was an invitation for leakage.

You would be correct.  (For those who aren't steam aficionados, 'outside admission' means that the steam enters at the valve cylinder ends, and exhausts to the 'middle', while inside admission does it the other way. Slide valves are inherently set up for outside admission, and hence the conversion also has to match the cored passages in the cylinder block.)

rfpjohn
In a book I have on the N.F.&D. there are pictures, before and after the second world war of a Light pacific 1226, class Ps. In the pre war shot, she has the Universal conversion. Post war finds her sporting a conventional piston valve cylinder block. I'm sure someone out there knows the real story, but I'm guessing that the Universal arrangement was found to be OK 'til a major shopping allowed the opportunity to upgrade to conventional piston valves.

I suspect there may be a bit more to this story, particularly if the locomotive in question is sporting other modernizations, particularly nifty gizmos like a feedwater heater, Valve Pilot device, or Foam-Meter.  Apparently a certain amount of work done to an 'older' locomotive rendered it 'new' for purposes of depreciation.  Coming off the 'high' of WWII, many railroads had plenty of income that would benefit from higher depreciation, as well as (all too brief in many cases!) access to capital.  So there was perceived benefit in doing upgrades to older power, even if comparatively little of the 'original' was left after the operation.  This was the explanation given to me for why the Frisco Mikados in the 1350 series (1351 is in Collierville, only a few miles from me) were 'rebuilt' from 1912-vintage 2-8-0s, but with feedwater heaters, boosters, and new just about everything.  I'm reasonably sure there was some of this logic in Reading rebuilding 2-8-0s into thoroughly modern 4-8-4s in about this same period.

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Posted by CSSHEGEWISCH on Saturday, May 11, 2013 6:45 AM

Also consider the original Paducah rebuilds by the IC during the steam era.

The daily commute is part of everyday life but I get two rides a day out of it. Paul
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Posted by Firelock76 on Saturday, May 11, 2013 6:54 PM

Gentlemen, check out who's back on "What steam we haven't seen."   Not going to tell you, it'll spoil the surprise.

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Posted by wattle on Tuesday, May 14, 2013 5:44 AM

I appreciate the big Americans were good and enjoy hearing about them dut I wonder if a garret built to the same scale would be more useful . In Africa they did amazing jobs both at tractive effort and speed considering track standards. In Queensland I know of one comment from an engine man that you had to make throttle changes a minute before necessary because of the length of the steam passages.

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Posted by Overmod on Tuesday, May 14, 2013 5:57 AM

wattle
I appreciate the big Americans were good and enjoy hearing about them dut I wonder if a garret built to the same scale would be more useful . I

The monster Garratt (note both spelling and capitalization, please) was discussed in Trains in the '70s, and is one of the 'timeless topics' on the Yahoo group 'steam_tech' (where I would refer you for discussions that are far more involved than would be tolerated for long on this forum!)

A principal problem is the fuel and water required for 'American-scale' operation.  Garratts lose adhesive weight on drivers as they use fuel and water.  The water issue can be handled by pumping from a trailing aux tender ... but then the useful length goes way up.  There are technical ways of getting fuel forward from trailing cars (I have developed a couple) but it's difficult to 'sell' them in practice.

Yes, there are some issues with the long steam lines, but nothing I think is particularly fatal.  Engine crews would need to learn about slower throttle (and cutoff) adjustment, but 'special technique' is also needed for other flavors of modern engine, particularly unconjugated duplex-drives.

I do believe that a Meyer configuration is better suited to North American requirements than a Garratt, but will not induce MEGO syndrome (another form of sleep disorder?) by going into it here.

RME

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Posted by rfpjohn on Thursday, May 8, 2014 10:51 AM

I'm sure you've all read that Western Maryland Scenic is going to restore and use C&O 1309, the 2-6-6-2 from the B&O museum. I like to think they got the idea from my posting from last year. Of course, I also like to think that I have this weeks lottery numbers and that I invented the cheese omlette.

I will definitely make a trip to Cumberland to watch that one run!.

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Posted by Paul Milenkovic on Thursday, May 8, 2014 12:56 PM

Overmod

A principal problem is the fuel and water required for 'American-scale' operation.  Garratts lose adhesive weight on drivers as they use fuel and water.  The water issue can be handled by pumping from a trailing aux tender ... but then the useful length goes way up.  There are technical ways of getting fuel forward from trailing cars (I have developed a couple) but it's difficult to 'sell' them in practice.

Yes, there are some issues with the long steam lines, but nothing I think is particularly fatal.  Engine crews would need to learn about slower throttle (and cutoff) adjustment, but 'special technique' is also needed for other flavors of modern engine, particularly unconjugated duplex-drives.

I do believe that a Meyer configuration is better suited to North American requirements than a Garratt, but will not induce MEGO syndrome (another form of sleep disorder?) by going into it here.

RME

I believe Wardale that the changing weight with consumables is a non-issue on a Garratt as it is on a Diesel with a belly fuel tank.

My big concern is the long steam lines.  The throttle lag could be cured by "front end throttles" closer to the cylinders.  What is more difficult to cure is the power and efficiency robbing pressure drop, both in admission and exhaust, of the long steam lines.  I guess you can cure the admission problem with a big steam chest near the cylinders, but how do you solve the exhaust back pressure problem -- automobile-style tuned exhaust "headers"?

The Meyer locomotive is often depicted with the cylinders facing inwards rather than outwards as on a Garratt, but I am thinking the Garratt's first loco had inward facing cylinders underneath the water tender and coal bunker.

The other big Garratt advantage is the unobstructed fire grate and ash space.  I could go for Meyer-style inward facing cylinders if it can shorten the steam lines.  But the unobstructed grate is a big deal for things like the Gas Producer Combustion System or related efforts.

If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?

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Posted by Overmod on Thursday, May 8, 2014 2:32 PM

Paul Milenkovic

I believe Wardale that the changing weight with consumables is a non-issue on a Garratt as it is on a Diesel with a belly fuel tank.

The problem is the torque peakiness on the reciprocating engines.  Diesel TMs have relatively even torque, and the fuel load is a relatively small percentage of the overall weight carried in the center of the locomotive.  The Garratt has the consumable weight representing most of the actual adhesive weight on the outer ends of the frame; asking the equalization to carry the load from the inner Garratt pivots is not going to work as the frame itself is what 'cocks' with the weight disparity.  The situation on a Mallet-Garratt, of course, is substantially worse, as the equalization isn't carried through the intermediate pivots and Alco-style control of the outer engines might result in too stiff a vertical compliance.

I have seen concerns over the need to de-rate North-American-scale Garratts relative to fuel/water consumption in too many places to believe it's an old wive's tale.  Mr. Wardale himself mentions the relative importance of normalizing the weight on engine units (see for example p.406 of the Red Devil). 

My big concern is the long steam lines.  The throttle lag could be cured by "front end throttles" closer to the cylinders.  What is more difficult to cure is the power and efficiency robbing pressure drop, both in admission and exhaust, of the long steam lines.  I guess you can cure the admission problem with a big steam chest near the cylinders, but how do you solve the exhaust back pressure problem -- automobile-style tuned exhaust "headers"?

Long steamlines are no longer a heat-loss issue, now that we have multiple-shield aerogel insulation.  If there is really a concern about these, they can be preheated via the same sort of tracer lines used to keep the cylinder blocks hot under their insulation.

Yes, you can use Wagner throttles with servo control (as on the ACE 3000) to produce the appearance of snappy throttle response, although in my opinion throttle action is already a bit too fast (particularly when requiring high force to move the main front-end throttle off the starting poppet) with respect to slip induction.  I'd prefer to see some form of slower loading that assured proportionality -- perhaps this could be done via fluidics with the Wagner throttles...

The exhaust back-pressure 'problem' is partly handled with very large, proportionally expanding profile exhaust plena.  You can 'tune' the header for a bit of pulse extraction, but remember that the "gas" involved is two-phase exhaust steam: rarefy it and it nucleates; compress it and it superheats.  So in my view the normal scavenge mechanics doesn't work the way it does with IC engines.

Note that locomotives work just fine with relatively large back pressure... in fact, it makes recovery from slipping more positive.  You design around it, and try to compensate by using the exhaust steam energy effectively in the Rankine cycle.

The Meyer locomotive is often depicted with the cylinders facing inwards rather than outwards as on a Garratt, but I am thinking the Garratt's first loco had inward facing cylinders underneath the water tender and coal bunker.

Of course, there are reasons why every successful Meyer, and every Garratt after the first one, has had the cylinders facing relatively outboard!  If the cylinders are inboard, adjacent to the firebox, maintenance there becomes an everlasting pain... and that's just one reason to avoid; getting steamlines in and out of that space requires the sort of approach used for the rear cylinders on the PRR Q1, but now with flexible and slip jointing...

Trust me -- you want the cylinders facing out!  Heat and pressure loss can be dealt with.  Poor DFM, not so much...  ;-}

The other big Garratt advantage is the unobstructed fire grate and ash space.  I could go for Meyer-style inward facing cylinders if it can shorten the steam lines.  But the unobstructed grate is a big deal for things like the Gas Producer Combustion System or related efforts.

For all intents and purposes, a Meyer firebox and a Garratt firebox can be identical in depth and GA; they both have no required structure under them.  The Garratt has a slight advantage if manifolding for Cunningham circulators is to be provided at the throat, but increasing the Meyer wheelbase even slightly provides room in that area.  Note that Wardale's 'final' proposal for ACE (what he calls the 'Mark 1-C') is much more a Meyer than it is a Garratt.  Shortening the absolute wheelbase of the locomotive is very desirable for most North American services that would use these locomotives (for example, on coal trains that are effectively siding-limited).

Unobstructed grate is relatively LESS important for GPCS, as you want to limit the primary air going through, and provision of the required 'process steam' can easily be made around or through truck or frame structure.  But there is little question that allowing the greatest possible vertical space between grate and crown is significant, as is having an easily-serviced ashpan (with ashaveyors that don't involve convoluted paths or required air blasts).  I suspect that the arrangement found on the N&W TE-1, with side-opening doors near rail level, might be a preferred configuration for either a Meyer or Garratt.

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Posted by ACY Tom on Friday, May 9, 2014 12:50 PM
RFPJOHN: Sure do thank you for the omelet! I read thru this entire thread today & revisited all the discussions that I've been a party to since about 1961. Very bittersweet. Since you have all that clout, do you think you can conjure up an EM-1 from some scrapyard? Maybe you can build one with your lottery winnings. I'd buy a ticket.
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Posted by rfpjohn on Saturday, May 10, 2014 4:33 PM

ACY: You're quite welcome. I would love to help you with the EM-1, but I had already allocated all my winnings to rebuild K4s 1361 and build a superheated full size reproduction of W.W.&F. #4. Unfortunately, I didn't even get a free ticket. What are the odds? My only hope is the royalties from the egg thing, but the patent lawyer isn't returning my calls. 

Perhaps I have expanded this topic as far as use can be wrought from it, but it sure will be great to see steam used twice in the east for the first time since 1960!

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Posted by ACY Tom on Saturday, May 10, 2014 9:34 PM
We take what we can get. I'll be right beside you, inhaling the coal smoke aroma, when 1309 starts breathing again.
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Posted by daveklepper on Sunday, May 11, 2014 3:15 AM

Recappping what I have written earlier:    Best articulated, both the N&W A and Y6, each for its purposes.  Best all-around non-articulated, N&W J.   Best non-articulated freight:  AT&SF Ripley-designed 2-10-4.

My opinion for what ever it is worth.

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