PRR Duplexes and Experimental Engines ( S1, S2, T1, Q1, V1 etc.)

40415 views
573 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    July 2008
  • 681 posts
Posted by Juniatha on Sunday, February 28, 2021 11:07 PM

Gary

at this time I cannot post a proper answer because I cannot post any picture / drawing / diagram - which I would need to lay out some connections between amount of steam / cylinder volume and the consequences on cylinder efficiency due to limits of valve gear. I wanted to post an indicated hp curve over speed which is essential to see the difference various cylinder volumes would make and the influence of more or less capable valve gear and cylinder steam passages.

Sorry for that. Maybe it will straighten out and I can then post the matter.

Ciao

Juniatha

  • Member since
    January 2002
  • 4,201 posts
Posted by M636C on Tuesday, January 19, 2021 2:52 AM

Juniatha

Hello Peter

Now this *is* a contribution - I didn't know of that project.

Thank you!

Juniatha

 

There is another from the Riddles, Cox and Bond period....

http://www.82045.org.uk/

Peter

  • Member since
    January 2019
  • From: Henrico, VA
  • 6,160 posts
Posted by Flintlock76 on Monday, January 18, 2021 7:40 PM

M636C
I suspect that the trade was piracy.....

Shhhhhhsh....  

They preferred the term "corsairs."  More respectable you know!  Wink

  • Member since
    January 2002
  • 4,201 posts
Posted by M636C on Monday, January 18, 2021 6:41 PM

I think it is fairly clear that the Spanish invasion plan left a lot to be desired, and was not carried out well.

I was looking at the text of Sir Henry Newbolt's poem, used in the song I posted earlier....

Drake he's in his hammock till the great Armadas come,
(Capten, art tha sleepin' there below?)
Slung atween the round shot, listenin' for the drum,
An' dreamin arl the time o' Plymouth Hoe.
Call him on the deep sea, call him up the Sound,
Call him when ye sail to meet the foe;
Where the old trade's plyin' an' the old flag flyin'
They shall find him ware an' wakin', as they found him long ago!

The second last line, which I've marked in bold, struck a chord.

A magazine for the RAN Submarine community is called The Trade...

For the fight with the Armada in 1588, Effingham, Hawkins and Drake brought their own ships as they were all privateers, twelve ships in all.

I suspect that the trade was piracy.....

Peter

  • Member since
    May 2012
  • 4,389 posts
Posted by rcdrye on Monday, January 18, 2021 7:35 AM

Drake also burned shipyards and cooperages, leaving the Spaniards with green wood for shipbuilding and barrel staves.  The barrel stave problem may have been worse than the leaky ships, since a very large proportion of Spanish crews suffered from dysentery during the Armada sailing.  Just shows how important water supply is for more than steam!

  • Member since
    January 2002
  • 4,201 posts
Posted by M636C on Sunday, January 17, 2021 11:41 PM

You reckon the Spaniards are still holding a grudge against English-speakers for that affair in the Channel in 1588?   - Flintlock 76

I would have thought so if I didn't know that the Spanish Armada's ships have the same problems as ours. We should have been more intelligent customers....

I think the British still have a grudge against Spanish speakers, but that dates from 1982....

The Spanish had ships at sea and we should have looked more carefully. But now we are buying from the British a design still on the drawing board. So nobody knows if it will work or what it will cost.

For years we built our own ships to British designs with a local design team that knew where the weaknesses were and quietly left them out (in a couple of cases by using Dutch radars instead of British units.)

Around twenty years ago I was involved in an effort to avoid buying the recent British Daring class destroyers. The Spanish destroyers aren't great, but they are better and much cheaper than the Darings which had technical problems we could predict years before they were completed. 

Peter

  • Member since
    January 2019
  • From: Henrico, VA
  • 6,160 posts
Posted by Flintlock76 on Sunday, January 17, 2021 9:30 PM

M636C
"saw us coming". (Is that term used in the USA with the connotation of a confidence trick?).

Oh yeah Peter, it's used here in the US all right, and has been for decades, and for the reason you've guessed at.  

You reckon the Spaniards are still holding a grudge against English-speakers for that affair in the Channel in 1588?  

And yes, "armada" is the Spanish word for navy.  In fact, the Spanish marine corps, the oldest in the world, is called the "Infantria Marina de Armada Espaniola."  (I think I got that right.) 

Their most famous veteran?  Miguel de Cervantes.  

  • Member since
    July 2008
  • 681 posts
Posted by Juniatha on Sunday, January 17, 2021 9:02 PM

IA and eastern

Juniatha what would be the right cylinders on the NYC Niagaras with 290 lb boiler pressure and 79 inch drivers. Gary

 
Hello Gary
 
Huuuh! That’s a question easily posted but difficult to answer.
There are several aspects to take into account:
For one first answer:
What line profile and what train mass and average speed is the engine supposed to work to? The NYC was largely ‘water level route’ – so hill climbing reserves could be laid aside. In fact from her relation boiler steaming capacity to cylinder volume the Niagara *was* an express locomotive – even if so powerful as to be able to pull regular tonnage freight trains over the system, too – namely the same tonnage as assigned to the Mohawks and the Berkshires.
Limiting cylinder dimensions by relatively small cylinder diameter with common piston travel provided for high speed rpm capabilities and reduced hammer blow for a given amount of balancing of reciprocating parts.
 
It's 1900h, unfortunately I have to leave now – but I will come back on that question tomorrow.
 
So long
 
Juniatha

 

  • Member since
    July 2008
  • 681 posts
Posted by Juniatha on Sunday, January 17, 2021 6:56 PM

Hello Peter

Now this *is* a contribution - I didn't know of that project.

Thank you!

Juniatha

  • Member since
    January 2002
  • 4,201 posts
Posted by M636C on Sunday, January 17, 2021 6:25 PM

Flintlock76

Then there's the legend of Drake's Drum.  If England's threatened with invasion beat the drum preserved at Buckland Abbey, Drake's home, and he'll come back with his fleet to fight 'em off. 

There's the tale that Prime Minister Winston Churchill had a Royal Marine drummer stationed at Buckland Abbey during the summer of 1940 when the German invasion seemed imminant to sound "Beat to Quarters" on Drake's Drum, just in case! 

 

There is of course a song, to be sung with a strong Devon accent..

https://www.youtube.com/watch?v=i4HPWXEIKQc

I'm quite familiar with the Devon accent, about half of the technical petty officers in the Royal Australian Navy in the late 1960s spoke with that accent... (as do movie pirates...)

Of course the Armada wasn't a surprise attack. Drake had attacked the Spanish Fleet in Cadiz, Spain in April 1587, destroying between 39 (Drake's estimate) and 25 (Spanish estimate) ships. That delayed the attack and Drake met it again in the channel in July 1588.

Since 1588, "Armada" has had the connotation in English of a huge fleet, but in Spanish it just means fleet or Navy.

The RAN decided a few years ago to buy a number of major ships from Spain. My feeling is that the Spanish, like the Swedes some years earlier "saw us coming". (Is that term used in the USA with the connotation of a confidence trick?). But now we are buying ships from the UK again....

Peter

 

  • Member since
    May 2011
  • 115 posts
Posted by IA and eastern on Sunday, January 17, 2021 9:51 AM

Juniatha what would be the right cylinders on the NYC Niagaras with 290 lb boiler pressure and 79 inch drivers. Gary

  • Member since
    January 2019
  • From: Henrico, VA
  • 6,160 posts
Posted by Flintlock76 on Sunday, January 17, 2021 9:23 AM

Then there's the legend of Drake's Drum.  If England's threatened with invasion beat the drum preserved at Buckland Abbey, Drake's home, and he'll come back with his fleet to fight 'em off. 

There's the tale that Prime Minister Winston Churchill had a Royal Marine drummer stationed at Buckland Abbey during the summer of 1940 when the German invasion seemed imminant to sound "Beat to Quarters" on Drake's Drum, just in case! 

  • Member since
    January 2002
  • 4,201 posts
Posted by M636C on Saturday, January 16, 2021 11:58 PM

Juniatha

Flintlock - a bit of everything?

I believe it could be made an example of what people can take up and endure if only they be made to believe a huge treasury can be sacked in if they succeed.

And then this picture of Drake on board of his ship with a few comrades comes to my mind, when he saw the huge Armada. He looked them over through his telescope, cooly analysed their weak spot: They don't know how to sail! They are much to close to each other. So he cold bloodedly made one bold decission: to sail right there and set them all aflame! In the end the whole enormous Armada went up in one hell's fire and but the few ships of Drake's and his companions were left. So he returned to report to his queen ..: 

"Job done!" 

 

add.:

Oh, and Flintlock, you wrote 

"Could explain a lot of history when you think about it."

Maybe: Could explain a lot of history when you drink about it.

= J =

 

The more common legend about Drake and the Armada is, from Wikipedia:

The most famous (but probably apocryphal) anecdote about Drake relates that, prior to the battle, he was playing a game of bowls on Plymouth Hoe. On being warned of the approach of the Spanish fleet, Drake is said to have remarked that there was plenty of time to finish the game and still beat the Spaniards, perhaps because he was waiting for high tide. There is no known eyewitness account of this incident and the earliest retelling of it was printed 37 years later. Adverse winds and currents caused some delay in the launching of the English fleet as the Spanish drew nearer, perhaps prompting a popular myth of Drake's cavalier attitude to the Spanish threat. It might also have been later ascribed to the stoic attribute of British culture.

I'm sure I've seen a painting of that scene and a plaque from 1883 illustrates it.

While there have been many Royal Navy ships named for Drake other names were more prominent, particularly after the first world war.

Peter

 

  • Member since
    September 2003
  • 15,402 posts
Posted by Overmod on Saturday, January 16, 2021 6:52 PM

Juniatha
Ok - accepted.

Thank you.

  • Member since
    January 2002
  • 4,201 posts
Posted by M636C on Saturday, January 16, 2021 6:08 PM

And the Brits dream of getting back to the times of Sir Francis Drake - however they don't dream of getting back to the days of Robin Riddles and Roland C. Bond (not to be confused with James) and E.S. Cox (Juniatha)

At least some Brits dream of that period...

https://www.theclanproject.org/Clan_Home.php

There is a long running British Soap Opera Heartbeat set in that period.

Peter

  • Member since
    July 2008
  • 681 posts
Posted by Juniatha on Saturday, January 16, 2021 5:29 PM

Overmod:

Ok - accepted.

= J =

 

  • Member since
    July 2008
  • 681 posts
Posted by Juniatha on Saturday, January 16, 2021 5:16 PM

Flintlock - a bit of everything?

I believe it could be made an example of what people can take up and endure if only they be made to believe a huge treasury can be sacked in if they succeed.

And then this picture of Drake on board of his ship with a few comrades comes to my mind, when he saw the huge Armada. He looked them over through his telescope, cooly analysed their weak spot: They don't know how to sail! They are much to close to each other. So he cold bloodedly made one bold decission: to sail right there and set them all aflame! In the end the whole enormous Armada went up in one hell's fire and but the few ships of Drake's and his companions were left. So he returned to report to his queen ..: 

"Job done!" 

 

add.:

Oh, and Flintlock, you wrote 

"Could explain a lot of history when you think about it."

Maybe: Could explain a lot of history when you drink about it.

= J =

  • Member since
    January 2019
  • From: Henrico, VA
  • 6,160 posts
Posted by Flintlock76 on Saturday, January 16, 2021 4:37 PM

SD70Dude
All that warm beer probably helped too.  

Well, the alcoholic beverages back then, beer, wine, you name it, were supposedly much  more potent than they are today.

Could explain a lot of history when you think about it.  Hmm

  • Member since
    December 2017
  • From: I've been everywhere, man
  • 3,193 posts
Posted by SD70Dude on Saturday, January 16, 2021 4:31 PM

Flintlock76

We toured the replica of Drake's "Golden Hind" about 20 years ago.  I couldn't imagine sailing it on a lake, much less around the world.

Either those 16th Century mariners were incredibly brave or they were out of their minds!

All that warm beer probably helped too.  

As for modern railroad arguments, GE vs EMD and is PSR Good or Evil can get pretty heated!

Greetings from Alberta

-an Articulate Malcontent

  • Member since
    January 2019
  • From: Henrico, VA
  • 6,160 posts
Posted by Flintlock76 on Saturday, January 16, 2021 4:25 PM

Juniatha
And the Brits dream of getting back to the times of Sir Francis Drake

I don't know, the way World War Two re-enacting's taken hold in Britain, to say nothing of all the Spitfire restorations I suspect now they prefer the era of Sir Winston Churchill!

At least the 1940's had electric lights and indoor plumbing!

We toured the replica of Drake's "Golden Hind" about 20 years ago.  I couldn't imagine sailing it on a lake, much less around the world.

Either those 16th Century mariners were incredibly brave or they were out of their minds!

  • Member since
    September 2003
  • 15,402 posts
Posted by Overmod on Saturday, January 16, 2021 3:07 PM

Juniatha
please note that I had reason for it

None whatsoever.  

To the extent there was any, it has been relieved from the present discussion.  Or any prospective further ones of similar nature.

  • Member since
    July 2008
  • 681 posts
Posted by Juniatha on Saturday, January 16, 2021 2:49 PM

Quote: "While I'm in no position to argue the merits of any of the participants in the discussion of various and sundry engineering issues"

See, this just exactly what I apprehended the risk will be: that regular members get uncertain about the matter at hand and don't know whom to believe - and that sends like 50% of my efforts straight up the chimney!

Quote: "the intensity of some of the participants convinces me of the merits of remaining a diesel (and straight electric) enthusiast.

Well - not too difficult to sort out me as the one having come on intense.  However, please note that I had reason for it - see above! And before posting I had sorted out about 90, well 85 .. ok, 83 % of intense 'radiation heat'. 

Direct electrics - uuh! There have been some very intense fi... - uhm - discussions about proper system to choose and adopt - about the everlasting project of how European railways could -if ever- understand each other to unify their systems into one and the same all over Europe. Main focus now are the super speed trains and their technical concepts - each one advertising their own. 

And the Brits dream of getting back to the times of Sir Francis Drake - however they don't dream of getting back to the days of Robin Riddles and Roland C. Bond (not to be confused with James) and E.S. Cox - nor to the days of Jaguar when the saying was: 'they are good cars, but you got to have two of them: one for driving and one to repair' .

=

- edited once -

  • Member since
    January 2019
  • From: Henrico, VA
  • 6,160 posts
Posted by Flintlock76 on Saturday, January 16, 2021 12:01 PM

Man, you want intensity?  Get trapped in a room with some Civil War or World War Two buffs!  Ay-yi-yi!!!  

Makes steam freak intensity look positively mild!

  • Member since
    March 2016
  • From: Burbank IL (near Clearing)
  • 12,296 posts
Posted by CSSHEGEWISCH on Saturday, January 16, 2021 10:17 AM

While I'm in no position to argue the merits of any of the participants in the discussion of various and sundry engineering issues, the discussion is quite informative to me but the intensity of some of the participants convinces me of the merits of remaining a diesel (and straight electric) enthusiast.

The daily commute is part of everyday life but I get two rides a day out of it. Paul
  • Member since
    January 2019
  • From: Henrico, VA
  • 6,160 posts
Posted by Flintlock76 on Friday, January 15, 2021 9:45 PM

Well.

Gents I'll say this much, if DiplIng Juniatha says it, you can take it to the bank! 

I don't know much about engineering (They wanted to call us "engineers" in the copier repair trade.  I wasn't no engineer, I was a copier repairman, and proud of it!) but I DO know that to be a "Diplom Ingenieur" in Germany you've got to be "A-Number-One" smart as a whip!  When I met David Stephenson at a train show and we discussed Juniatha, out mutual aquaintence, we both agreed. 

Not trying to start a fight with Brother Overmod, who I enjoy as a friend (I hope so! I love you all!) but I wouldn't mess with someone who's got a VERY ominous-looking B-52 in her arsenal.

That picture's scary!  Surprise 

*  "Pennsy's T1 Reassessed."  Classic Trains special issue "Steam Glory 3," from 2013.  Kept it!  No way was that issue going into the recycle bin!

  • Member since
    July 2008
  • 681 posts
Posted by Juniatha on Friday, January 15, 2021 4:59 PM

Dear Professor (hon?) Overmod!

 

 I must say, this is an especially boastful sassy effrontery! I must put this straight: there is little if any real arguement in all the many lines  you shoved up to burry me under. So I regard this as a personal insult, an attempt to crush each and everything I have written - and have written orderly in full knowledge of the physical laws that play a part in these things I have described. 

However I sense you felt obliged to jump to 'rescue' age-old so understood male tech talk superiority over so-misunderstood menace of today's feminist's attempts to intrude each and every remaining male resorts. How wrong you are - me, I'm in no way intending to intrude anywheres, I'm just interested in steam locomotives just as anybody else in this forum may be or may not. Only, due to my being a Diplom Ingenieur still with a classic study of Maschinenbau I can sort out some things that often get entangled in conversations - nobody needs to feel like I stepped on his toes. Cool down Over(sic!)mod!  The world will be there tomorrow!

 

As things are, I can only recommend to all readers to ignore this lengthy, winding and at points illogical and  conflicting reply and spare yourself to get confused.

 

Now, in order no one can say I make it too easy for myself, I will at least reply on some of the 'points' brought up against me within each the shreds of my text:

 

1. shred:

Quote: "This is not necessarily complete tripe; it is possible that, using the 'reservoir' of supercritical water and excess available superheat at high draft level, there would be 'enough steam' to produce the necessary acceleration.  Not particularly cost-effectively, and with no guarantee that the locomotive would hold speed (or continue acceleration) beyond a few seconds or minutes, but the higher cyclic does translate into greater cylinder horsepower up to the point that the valves and gear cannot"

Yes, this *is* complete tripe! And the accusation right with it. What is a 'reservoir of supercritical water' in a conventional steam locomotive? do you know at all what the supercritical stadium of water implies? It is by faaaaaaaaar out of reach of a classic steam loco! Absolute rubbish, just meant to dazzle and deceive an unexpecting person.

'excess available superheat' - where is that and how does it come together? There is non - just baloney!

'there would be 'enough steam' to produce the neccessary acceleration. We learn here physics turned upside-down: in order to produce more ihp you just speed up the acceleration - that no-one has ever come about that! It's so simple! Sports car manufacturers rack their brains about super-powerful engines when all you need is to produce -first- the demanded acceleration - and -second- power output of the engine will follow accordingly! Gee - that's cute, I love it. 

(My goodness - this is *not* about the amount of steam but about cylinder performance: *this* cannot produce *higher* t. e. at *higher* speeds even on the same c/o!)

Now, if you suggest to pull out c/o open (lengthen intake) at *increasing* speed you turn upside-down known sound locomotive handling. Of course this would go with a large increase of steam demand and the whole thing in fact means a sluggish (easy) loco working at slower speeds offset by an increasingly harder working as speed increases to the degree of even handling c/o in the *opposite* way of normal, and leaving much non-used  t. e. and acceleration in the slower speed range. Now, who would drive a locomotive in this absurd way?

"no guarantee that the locomotive would hold speed (or continue acceleration) beyond a few seconds or minutes, but the higher cyclic does translate into greater cylinder horsepower " A few seconds ... gee! The 'higher cyclic' translates into greater cylinder horsepower: Again, it does not help to have *any* amount of steam - cyclic or not - if valve gear cannot pass it through cylinders. In regular driving the higher the speed the more throttling occurs in the steam passages and therefore less t. e. - excess steam will be blown off by safety valves in the good old way - wether this extra steam comes in cyles or continuously.

"Do I really think that acceleration all the way from "80 to 100" would be faster than "60 to 80"?  Not really..."   Now, what's that? First you claim it is possible - then you don't believe - yes: - yourself? Then, why should anybody else? This note goes around full circle.

 

2. shred:

"the old story about the Super Hudson design providing too much 'thrust or kick' and bending rods would be far more applicable to the Niagara.  It might be interesting to run comparative numbers for the Niagaras at original vs. stepped-down pressure to assess what the 'right' cylinder dimensions for 265psi would have been."

Completely mislead beause the two classes were two seperate designs. The quoted would only have been correct if both would have been equipped with one unified set of rods! That was not the case, and thus which one was underdimensioned cannot be established by 'running comparative numbers for the Niagaras at original vs stepped down pressure' . How should that show correct cylinder dimensioning??? In regular locomotive construction question would rather be to correct rod dimensioning for 'what the 'right' cylinder dimension for 265 psi would have been'  All in all this is completely off the topic. I never dealt with a 265 psi b. p. setting of the Niagara - it was never a question. If Prof Overmod thinks since some J-3a had been reduced, the Niagara should as well have been reduced the same way, this is his personal believe  - there is no point against anything *I* said in this. How and why can the propper cylinder dimensioning only be determined at 265 psi? It's  very simple mathematics to establish what cylinder volume for 275 or 290 psi or for 265 psi for each a desired t.e.

 

3. shred:

"But the issues with Niagaras did not involve "greater peak horsepower" -- the water-rate considerations even on a railroad with frequent track pans would have become significant "

There I wrote that the extra power output would have been produced just by a lower specific steam consumption and *no* more steam (btw: i e *less* steam on any lower than maximum ihp!) - and still here are water-rate considerations put up against what I wrote!  And where did I write that 'issues with the Niagaras did involve "greater peak horspower"? To criticize a text it is of advantage to read it first - and understand that this was *my own* comment as to Kiefer's choice of cylinder volume for 275 psi (too small for best thermodynamic efficiency in my view) 

"if you look at the assumptions behind the detail design of the NYC 5550 (and inherently in the April '45 spec for the C1a) you will see this very clearly. " NYC 5550? chee-chee-chee! Congratulations if you have information about the never-to-be C1 class - but what has that design ever to do with *my* contemplations about the Niagara? What will I see clearly?

"Reading between the lines, I suspect there were the same kinds of failure that N&W was seeing with the extended #4 driver-pair pins " Now it gets ever wilder: now the design of coupling rods interfere with steaming of boiler and with cylinder dimensions - O-M-G!

"#4 driver-pair pins on the original lightweight J rods; the Niagara design was somewhat more susceptible to priming "  Now that's the peak: coupling rods design and priming in the boiler - another connection so far ignored by even the most notable steam specialists!?

 

4. shred

"found a point of failure that came up 'quicker' than valve-gear problems: insufficient valve lubrication (or dimensional clearances)  .. and insufficient valve lubrication is not a valve gear problem? What is it then?

"as Ed King memorably put it, that was not a factor in the infamous test failure on PRR either by the noted results or later discussion of the testing by Cover et al. as preserved at the Hagley."  Once again: "infamous test failure on PRR either by the noted results or later discussion" Failure by results or by later discussion! Great - I say nothing further! General: now, here you are! If that does't impress the last ignorat bloke! I'm only born in 1976 and by that must bow to the superior mass of historical name dropping here - may I know of physical technology whatever I may. Namedropping used at precisely the right moment has silenced many people - but what is the precisely right moment in a writing? Btw - what is it to tell us? Sorry, I'm always so unimpressed and down to earth.

 

5. shred

My writing: "Mind that with a 20% over-revving, forces reach 144% of the design maximum". and Overmod: "Especially if Chapelon was correct in his assessment of 'routine' lateral bending in the Timken narrow-section lightweight rods."  Plain NO here!  The increase I mentioned comes from increase of rpm only - no mechanical bending involved! Full stop!

"over-revved continuously, rather than (as was clear to me) repeatedly high-speed slipped without proper notice -- as in the case of the "130mph and higher" operation"

What is the dfference between the two? revving is revving - no matter if it produces speed over rails or slip over rails - especially when slipppage is "without proper notice" (i e goes on over longer than a moment's time). It's the centrifugal forces that matter here!

"The combination of inertial and shock forces on lightweight rods in high-speed slipping is, if anything, far higher in the deleterious senses than steady-state high speed would be, and probably makes your point even more compelling." Deleterious - hu-hu-hu! No, absolutely not! Again: inertia is *only* dependant of the level of rpm. What shock forces are there in slipping other than in regular high revving? *Far* higher? Seems, if the high speed slippage comes into proper frequency of the drive axle(s) there could be torsion forces and momentary lack of straight 'in line' running of wheels and an increase of over / under speed every 1/4 of revolution. Creepy, somehow, isn't it! That's why designers usually took more notice of that than of other forms of slipping

 

6. shred

"You're leaving out the enormous amount of maintenance that was used by railroads like the Pennsylvania or NYC to keep a jointed-rail mainline in proper shape. "  No, I do not. First, such maintenance as would be needed to keep a jointed and nailed rails track without the typical low spots and bends certainly did not exist - I can say that because the American railroads were economic enterprises and such a sort of maintenance would have simply exploded their maintenance budget, it would have demanded revamping embankment under the joints in comparatively short intervals and straightening / replacing bent rails, really an enormous effort - for sure not in the economic interests of railroads making the bulk of income by freight trains. Further, I saw the real riding over the assumed best of these tracks in the advertising film: bounce-bounce-sway-bounce! Last not least logic (wow this is hard from a woman, I know!) must tell you that with this sloppy sort of  track system (nailed rails with always some 15 - 25 % of these nails more or less pulled up) you can *never* compete with modern continuously welded track with sprung double screws on rails into much sturdier sleepers and embankment of defined and clean granite broken stone ballast with alongsides superelevated shoulders to keep the track where it was laid and precision adjusted - the result being a passenger in an ICE or TGV feels smooth like in an airplane in perfectly calm flying weather - no bouncing at all and that not at 120 mph but at 175 mph! Note: you may have a superior knowledge of old times - but don't even try to compete with me in today's technology!

"There are a number of reports -- whether anecdotal or 'doctored' I can't say," Well exactly that is the point - this way 'doctored' i e manipulated reports get involved and when that's the case I quit because then there is no way of sorting out what was true and what was not.

" one of these stories claims the ride on a T1 was considerably better than in 'the business cars behind'" 

That would be a unique and really singular turning upside-down of what is normally found everywhere in the world! And oposite of what I saw in that video: the riding of the - fairly new! - T1 was certainly worse than that of the lounge car also filmed at about the same speed; it was rough to say no more: the engineer at one time was even lifted from his chair for a moment in a rebouncing action of the engine and the view along the boiler showed nosing and twisting more than on a run-down 012 Pacific: as much play they had developed in bearings, most all of them always ran dead straight ahead - to a part again result of really good track maintenance on federal DB back then (it is not the same today, off the ultra-high speed lines).  In the coach compartment I could stand a 5 DM coin on the table on its edge in direction of travelling and it wouldn't fall for minutes on end before I finally lost patience and took it back again. I had done that when joining my father back then on a trip to Frankfurt - that was the quality of riding in an Intercity train with a 103 class twelve wheel electric at 200 km/h. 

 

7. shred

" In any case my personal, and essentially unjustified, opinion is that PRR made a great more out of high speed running than their actual plant ever really permitted except in a few, fundamentally virtually unimportant, sections.  Some of the discussions of doubleheaded K4s up against their practical speed limit (of about 92mph) mention the most alarming loss of compliance or guiding integrity on curves " 

Oooops??? Now, there you are - and after a whole chapter of claiming the 'jointed and nailed rails track' to have been as good as .. oh, come on! 

Btw - I saw an old super-8 film by a friend travelling the cab of a DR (DDR) two cylinder 03 Pacific (Berlin-) Buechen - Hamburg in 1970 when the driver had - as they then often did 'let her go' and see 'what she could do' on that stretch of well maintained DB track: in fact 145 km/h or 90 mph the guy had stopped them, with 12 coaches, some 500 t metric.  Shortly before reaching Hamburg they ran straight line through a small station over high speed switches and then into a wide left superelevated curve. On the switches the engine joggled somewhat then fell back into her unimpaired straight forward running and entered the curve smoothly, maintaining her unimpeded running - no nosing whatsoever. Side remark: what all these engines had was a motion I called 'gallopping' due to the comparatively large mass of reciprocating parts with about just ~ 12% overbalancing, you could see that by the window cut-out vibrating in rpm mode when filming the driver sitting still. (added paragraph Jan 16th)

 

8. shred

"This is not a major factor for the PRR T1, at any rate, which used an OC gear with lower travel at shorter cutoff, and valves with comparatively low inertia." 

My goodness, the other way around! there is much less inertia force in continuously rotating cams than in oscillating cams. This is so self explaining, I will not go into it here! Speed, rpm speed in this case! is a universal physical influence on anything - T1 or not - there are no exceptions in application of physical laws.  Ok, I stop here, it makes no sense to pursue this to the very end - there is nothing else but always the same. 

 

To be sure:

Anyone may have their own ideas and preferences or convictions - but the I claim the same right for me and please leave me alone with this sort of stalking really! Ever since the day you claimed the delta truck  of my 2-8-8-6 to be "almost"  where it should be it was like that: whenever I had posted something - anything! - popp! there was a criticizing comment of your's to it! Look, that six-wheel delta truck was not just 'almost'  where it should be - that was an insult to an engineer. I can rightfully say that since I designed the layout of the whole locomotive I put things *exactly* where I want them to be and that is *exactly*where they belong because I know what I'm doing. Back then I really got weary of it and in the end I just quit posting here. Now, again the same! But now I will not quit again - you have to throw me out if you can't stand my words.

 

I offer you the following agreement: 

 

You don't comment my postings anymore - and vice versa I do not comment yours!  

Would that be an acceptable compromise to you, Mr Overmod?

 

In this sense

 

All the Best for the New Year 2021

Juniatha

 

-52 overfly in stary night

(edited Jan 16th 21)

  • Member since
    May 2012
  • 4,389 posts
Posted by rcdrye on Friday, January 15, 2021 4:21 PM

One change NYC did make to the trucks was to replace the standard wheels with cylindrical (non-tapered) wheels.

The track section was 127 lb. jointed rail.  The test area was lifted and resurfaced, but was still below NYC standards. 

  • Member since
    September 2003
  • 15,402 posts
Posted by Overmod on Friday, January 15, 2021 10:36 AM

SD70Dude
I'm going to guess that RDC's have a compressor directly driven by the engine.

That would be correct.  As I recall there was some discussion (in Don Wetzel's account) about having both engines available for redundancy.

... were any modifications made to enhance the braking performance of this unit?  In particular I'd be concerned about brake fade (overheating). 

None necessary.

Remember that this was not intended as a 'service train', nor was it expected to make the equivalent of 'touch-and-go' acceleration and deceleration.  Much of the acceleration from high speed would be in part aerodynamic resistance, well down into the range the existing disk brakes would serve nicely.

We had some discussions about the APT designers' perceived need for hydrokinetic braking (from 150mph) in light of what these jet trains could achieve.  In particular this was a relatively light test article, running on a dedicated (and traffic-protected) stretch of track without fixed speed restrictions or slow orders.  And it used proportional passenger braking.  As I recall, no untoward action from the braking was observed during the tests.

I remember thinking as a kid that it might be possible to use what was then called 'beta thrust' to help with the deceleration -- I think the Bennie Railplane was intended to do that by reversing the pitch of its propellers, and I suspect the Russian "HSR Listowel and Ballybunion" might have done the same.  The ex-B36 pod did not have any provision for reversers, to my knowledge, but I suspect the capability could have been provided on following 'articles' without too much despair.

  • Member since
    May 2012
  • 4,389 posts
Posted by rcdrye on Friday, January 15, 2021 6:41 AM

Getting off track here - why not?  The chase GP7 would have been able to pump up the air reservoirs.  As far as I can find out they didn't do any brake mods.  The good old Budd discs (presumably with Rolakron anti-lock system) were probably just fine.  I think the track in use was probably cleared all the way from Toledo to Elkhart.

SUBSCRIBER & MEMBER LOGIN

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

FREE NEWSLETTER SIGNUP

Get the Classic Trains twice-monthly newsletter