Yeehah, round one:
if C&O is a pipe fitters nightmare, the front piping of Y6b-classes is Freddy Krugers dream in ELM-Street ;-)
BigJim You two love birds must be smoking a "crowd pleaser"
You two love birds must be smoking a "crowd pleaser"
Hey, bash my BigBoy, not us, or can't you? Or did you indirectly confirmed my pov?
BigJim Pass that stuff back over here.
Pass that stuff back over here.
Sorry Boy, that is no toy for the kids :-) Just kidding, you are all right. If eyes feel attractive with something, usually you stay liking it, it happens rarely something else comes around the corner and your eye is liking it more...
N&W fleet had its own corporate design, they had a very distingueshed apperance, other roads had their look 'n feel.
To be honest, in an objective pov, it is not my personal absolute favourite one, best looking and probably most versatible articulated ever, was B&O EM-1 class. They contain a very nice, fresh look.
Have fun!
BigBoy4017Concerning loco asthetics, my wife thinks the Y6b is an ugly loco, me and all you can not disagree with her ;-) The pipes on the Y6b seem to mangle the whole engine like a snake, probably that is the reason for choking HP at speeds ;-) Where are the clean lines? The Class A looks like its whole boiler and smokebox will fall behind on the rear truck one day, the whole things looks pushed back. It has also the most ugliest pilot, ever seen.
my wife thinks the Y6b is an ugly loco, me and all you can not disagree with her ;-) The pipes on the Y6b seem to mangle the whole engine like a snake, probably that is the reason for choking HP at speeds ;-)
Where are the clean lines? The Class A looks like its whole boiler and smokebox will fall behind on the rear truck one day, the whole things looks pushed back. It has also the most ugliest pilot, ever seen.
Well, that is hilarious. I may have taken you seriously until you said that. You two love birds must be smoking a "crowd pleaser" to cast a blind eye to the fleet of C&O pipe fitters nightmares.
I'm still laughing.
.
Big Boy; being under the impression that some steam engines were designed to do a specific job, I wonder how looks got into the design . Some things were hung on because of an after thought.Didn't help the looks at all. Mr Loewy had a good looking engine. Not too much hung on as an after thought, but that was a passenger engine and I don't recall seeing one hooked to a freight concist. One could guess you don't tie a racehorse to a plow or a plowhorse to on a racetrack no matter how much " shine" is used. However, N&W did hook up Js to freight on time manifest. Just my two cents worth.
Respectfully, Cannonball
Y6bs evergreen in my mind
Hi Juniatha: If you're interested in new ideas on steam aesthetics, how about a little commentary on steam turbine locomotives. I know of four examples, Union Pacifics' pre WWII experimental, Pennsylvania' No. 6000, the C&O's passenger turbines and Norfolk and Western"s Jawn Henry. I'll start the ball rolling by asserting that, aesthetically speaking, the Union Pacific and C&O turbines were terrible! Overly sculptured, poorly balanced and painted in garish colors they were not fit for refined analysis! The Pennsylvania's 6000 was an attempt to mate the turbine concept with a more-or-less conventional steam configuration. The 6-8-6 wheel arrangement was balanced, the boiler was in good proportion to the whole locomotive and the tender was a graceful modern configuration essentially drawn from the T-1 concept. N&W's Jawn Henry was square and austere with moving parts hidden like a diesel but she ( pardon me Jawn! ) sure looked a brute and seeing and hearing her it's hard to believe she peaked out at around 4000 HP. It should have been much more! So, in terms of pleasing aesthetics, I'd rate Jawn Henry first for a massive but clean design, Pennsy's 6000 next for trying to preserve the classic steam look and the two others beneith contempt!
To Big Jim: Why were the T1's and the Baldwiin diesels referred to as "Shark Noses"? Who knows? Obviously someone called them that at the beginning and the name stuck, sort of like that unknown ALCO employee who chalked "Big Boy" on the smokebox of the first UP 4-8-8-4. Sometimes the stars align just right and the rest is history.
Oh, by the way, I like Juniatha's green scheme on her T-1 selection palette. Not Brunswick Green of course, more like Lionel's version of Brunswick Green, which looks better than the real thing anyway.
Oh boy, oh boy oh boy! The picture of that UP 9000! What wouldn't we give to see that machine running again! Twelve drivers! Yeah, the smokebox mounted air pumps are kind of funky looking, but I can look past that to the sheer spectacle of the thing. Sadly, as a three cylander design, probably there's few restorers that would be willing to take a crack at it.
BigJim What type looked better - early Challenger or straight twelve coupled 9000 class? I've never been a fan of smokebox front mounted air pumps. The 4-12-2 needs a larger tender to lose the stumpy looks. As concerns steam aesthetics - had steam continued could there have been a design joining both A class and Y-6 class features to advantage? At one time there were plans for a Y7. This was to be a four cylinder single expansion 2-8-8-2.
What type looked better - early Challenger or straight twelve coupled 9000 class?
I've never been a fan of smokebox front mounted air pumps. The 4-12-2 needs a larger tender to lose the stumpy looks.
As concerns steam aesthetics - had steam continued could there have been a design joining both A class and Y-6 class features to advantage?
At one time there were plans for a Y7. This was to be a four cylinder single expansion 2-8-8-2.
...and here are some drawings, if someone is interested to built one:
http://www.nwhs.org/archivesdb/filterdocs.php?index=rs&id=2907
BigJim Deggesty: [snip; quoting BigJim] "At one time there were plans for a Y7. This was to be a four cylinder single expansion 2-8-8-2." Would this have designed for fast freight service, with few protuberances that create turbulence? When was this proposed? Johnny & Juni, The following information is taken from the book "N&W: Giant of Steam" or "N&W: Giant of Steam - Revised Edition" by Bud Jeffries which I highly recommend. A basic line drawing of what the Y7 may have looked like is shown in the book. It was thought that a more powerful locomotive than the Class A and Y6 was needed to increase the speed of of heavy freight. So, from early 1936 to July 1937 a loco was designed to be as big as clearances would allow. Some specifications are 112 inch maximum outside diameter boiler, 26 X 36 inch cylinders, 63 inch drivers, TE 153,000 lbs., grate area 130 sq. ft., 23 ft. over the tubes, evaporative heating surface est. 7,100 sq. ft., and superheater surface est. 2,900 sq, ft. Air & feedwater pumps were to be mounted on the smokebox front to meet clearances. Because in July 1937 federal legislation was introduced to limit train lengths to 70 cars the Y7 died on the spot. The entire project cancelled in Feb. 1943. "The seventy car limit was not imposed , but by the time that was resolved, the N&W had "off-the-shelf" steam power that was more than able to carry it to dieselization some twenty years later." I have previously given my thought on the aesthetic properties of front mounted air pumps.
Deggesty: [snip; quoting BigJim] "At one time there were plans for a Y7. This was to be a four cylinder single expansion 2-8-8-2." Would this have designed for fast freight service, with few protuberances that create turbulence? When was this proposed?
[snip; quoting BigJim] "At one time there were plans for a Y7. This was to be a four cylinder single expansion 2-8-8-2."
Would this have designed for fast freight service, with few protuberances that create turbulence?
When was this proposed?
Johnny & Juni,
The following information is taken from the book "N&W: Giant of Steam" or "N&W: Giant of Steam - Revised Edition" by Bud Jeffries which I highly recommend. A basic line drawing of what the Y7 may have looked like is shown in the book.
It was thought that a more powerful locomotive than the Class A and Y6 was needed to increase the speed of of heavy freight.
So, from early 1936 to July 1937 a loco was designed to be as big as clearances would allow. Some specifications are 112 inch maximum outside diameter boiler, 26 X 36 inch cylinders, 63 inch drivers, TE 153,000 lbs., grate area 130 sq. ft., 23 ft. over the tubes, evaporative heating surface est. 7,100 sq. ft., and superheater surface est. 2,900 sq, ft. Air & feedwater pumps were to be mounted on the smokebox front to meet clearances.
Because in July 1937 federal legislation was introduced to limit train lengths to 70 cars the Y7 died on the spot. The entire project cancelled in Feb. 1943.
"The seventy car limit was not imposed , but by the time that was resolved, the N&W had "off-the-shelf" steam power that was more than able to carry it to dieselization some twenty years later."
I have previously given my thought on the aesthetic properties of front mounted air pumps.
Johnny
mcsauerkraut_141 GP40-2: Why? Because some people have the mistaken idea that the Y6 was a really big engine, when in fact when you compare its boiler capacities to other articulated locomotives, it was quite small. Since this thread is about "aesthetics" I will say that the N&W Y Class was in my opinion the best looking compounds made. I think they were fantastic locomotives for their intended use, but it is nuts to think they could be an effective replacement for a more powerful, larger boiler locomotive like an Allegheny or Yellowstone in faster service assignments. A big engine is not necessarily a powerful engine. If you compare some design datas of p.e. the N&W A to the C&O H-8 you'll find, that the "Allegheny" in order to match the specific power numbers of the A (like drawbar horsepower/engine weight – without tender, of course) would have been able to produce more than 10.000 dhp - it really could make some 7.800. The C&O would have done better with a big Yellowstone than with the H-8, in order ot pull coal drags over the hill. In reality, the A outperformed the H-8. A H-8 took a 14.000 t coal drag over the line. The A pulled 16.000t - 17.500t - and they did it at higher speed!
GP40-2: Why? Because some people have the mistaken idea that the Y6 was a really big engine, when in fact when you compare its boiler capacities to other articulated locomotives, it was quite small. Since this thread is about "aesthetics" I will say that the N&W Y Class was in my opinion the best looking compounds made. I think they were fantastic locomotives for their intended use, but it is nuts to think they could be an effective replacement for a more powerful, larger boiler locomotive like an Allegheny or Yellowstone in faster service assignments.
Why? Because some people have the mistaken idea that the Y6 was a really big engine, when in fact when you compare its boiler capacities to other articulated locomotives, it was quite small. Since this thread is about "aesthetics" I will say that the N&W Y Class was in my opinion the best looking compounds made. I think they were fantastic locomotives for their intended use, but it is nuts to think they could be an effective replacement for a more powerful, larger boiler locomotive like an Allegheny or Yellowstone in faster service assignments.
A big engine is not necessarily a powerful engine. If you compare some design datas of p.e. the N&W A to the C&O H-8 you'll find, that the "Allegheny" in order to match the specific power numbers of the A (like drawbar horsepower/engine weight – without tender, of course) would have been able to produce more than 10.000 dhp - it really could make some 7.800. The C&O would have done better with a big Yellowstone than with the H-8, in order ot pull coal drags over the hill. In reality, the A outperformed the H-8. A H-8 took a 14.000 t coal drag over the line. The A pulled 16.000t - 17.500t - and they did it at higher speed!
Dear mcsauerkraut_141,
no, unfortunately that is (was) never true, and believe me, before GP-40 will give a comment on this with his sarcastic , but thouroughful honest manner (and he his right on technical topics), please allow me to settle this:
From the Jeffries book it will tell you, they only did ~5400 DBHP at ~40mph, while the Allegheny put almost ~1000DBHP more., concerning a speed-range from ~35-60mph. It was, given a working speed range from zero to 70mph, the most powerful loco. Not at all circumstances, like starting or low speed tractive effort, but from 25mph and up, it really shined. It had also a way safer factor of adhesion, than the A, making it more sure-footed in the mountains.
The N&W was lucky, it had a line where its trains run on a slight downhill non-stop, therefore they could use very heavy trains and moved them fast. N&W's usage of trains and engines was probably benchmark for its time.
It is the same "rubbish", like one author published Big Boys or others could be easily substituted with the "smaller" Y6b classes. Basically, almost each loco could be substituted with another one, changing train wheight and speed. But whole train movements and operation needed to be changed, too. At 60mph, tractive effort was nil for Y6b, meaning power was just enough to keep them running level at that speed, without any car attached to them.
At the speed of 50mph you would need round about 2 and half men or Y6b-Classes, to substitue 1 Big Boy (or Class A, or AT&SF 5011 Class, or other modern Yellowstones), for example. You needed even more, to substitute one Allegheny at that speed.
Concerning loco asthetics,
Anybody got teased? Ready to rumble? Now, you may bash my favourite loco, Big Boy.
Which brings to mind...
Why in the world were the T1's and Baldwin diesels refered to as "Shark Nose"? They never have looked like any shark I have ever seen. Actually, the T1 looks more like a WWII Fleet submarine.
GP40-2 Why? Because some people have the mistaken idea that the Y6 was a really big engine, when in fact when you compare its boiler capacities to other articulated locomotives, it was quite small. Since this thread is about "aesthetics" I will say that the N&W Y Class was in my opinion the best looking compounds made. I think they were fantastic locomotives for their intended use, but it is nuts to think they could be an effective replacement for a more powerful, larger boiler locomotive like an Allegheny or Yellowstone in faster service assignments.
But let's go back to aesthetics:
I confirm with GP40-2, that the Y5/Y6 belong to the best looking american steam engines, since they look exactly like what they are: powerful work horses which say: “Give me a yard full of loaded coal hoppers and let me empty it.” The Y5/Y6-class was a really great steam locomotive.
They were beautiful designed engines, compact, in all aspects "reduced to the maximum".
The Y7 was never built due to the fact, that it could not better perform than the A and the Y6, respectively.
But in order to good looking engines: Why does the M-4 Berkshire of the L&N look so much better then Eries S-1 or the B&A A-1?
To me, it is the clear lined boiler without any chaotic plumbing, even the sand pipes were covered. The harmonic lines of drivers, running board an tender and some more.
And - allow me just a few words on smoke deflectors: Their usefulness in lifting exhaust steam and flue gases high above the cab and the train is somewhat doubtful. Well, they worked quite good with engines having a very low back pressure and a not very good draft like the German standard designs.
Indeed, there influence on locomotive aesthetics is enormous. If you look at the UP 800s, without their Dumbo-like wings they look small and a little bit slow. The smoke deflectors change this radical: Even if they were much too large, Juniathas oversizes Witte-eings for the T1 reflect that impression.
Those tiny Witte-wings were not only designed to obtain wartime material savings, they resulted from the experience, that the the lower parts of the big elephant ears hat no positive influence on aerodynamics and air flow around the front end of the engine.
I have some doubts, that smoke deflectors would have worked well with the shark-nose front of the T1... However, they look quite interesting, but I prefer Pennsy T1 without them.
Deggesty [snip; quoting BigJim] "At one time there were plans for a Y7. This was to be a four cylinder single expansion 2-8-8-2." Would this have designed for fast freight service, with few protuberances that create turbulence? When was this proposed?
Paul of Covington Why the commotion about the Y6 and horsepower? There were several locomotives with higher horsepower than the Y6, but the Y6 was designed for tractive effort, and in this, if I'm not mistaken, it could out-pull anybody.
Why the commotion about the Y6 and horsepower? There were several locomotives with higher horsepower than the Y6, but the Y6 was designed for tractive effort, and in this, if I'm not mistaken, it could out-pull anybody.
Why? Because some people have the mistaken idea that the Y6 was a really big engine, when in fact when you compare its boiler capacities to other articulated locomotives, it was quite small. You are correct, it was designed to produce good pull at relatively slow speeds. When discussing tractive effort, you need to quantify at what speed and what level of adhesion. Using Jim's data of a Y6/Y6b weight of 582,000 lbs, with 522,000 lbs on the drivers it would have had an adhesion factor as low as 3.4 at a starting tractive effort of 152,000 lbs. That's suboptimal especially on worn or wet rail for a steam locomotive. However, that 152,000 lbs effort was only when starting all 4 cylinders with live steam. With its limited boiler capacity, the engine had to quickly switch over to compound mode, and the tractive effort dropped to 126,000 lbs with an adhesion factor of 4.1. This was a good level of TE and adhesion, but hardly earth shattering. Ramp the speed up to 45-55 mph, and you will find an Allegheny or Yellowstone class producing a least double the tractive effort of a Y Class.
Since this thread is about "aesthetics" I will say that the N&W Y Class was in my opinion the best looking compounds made. I think they were fantastic locomotives for their intended use, but it is nuts to think they could be an effective replacement for a more powerful, larger boiler locomotive like an Allegheny or Yellowstone in faster service assignments.
Juniatha Hi Crandell No problem with me – it's actually Big Jim's thread ... Juniatha
Hi Crandell
No problem with me – it's actually Big Jim's thread ...
Juniatha
Cripey....this has gone through so many changes that even I am confused. Quite right, Juniatha, it is Big Jim's thread, and I apologize to you both.
Crandell
Setting aside the achievements of modernization, and looking just at aesthetics in a vacuum, I believe the best-looking U.S. locomotives were built in the 1890-1910 era. In that time frame, locomotives had not yet expanded to fill up the clearance diagram, so their features could be more prominent and expressive. I see some incredible beauty in some of the ten-wheelers, and early Atlantic types. The CMStP&O class I-1 ten-wheelers built by Also-Schenectady are an example with canted cylinders with inside piston valves, clerestory cab roofs, and a modernized version of the older tender trucks using a telescoping, non-weight-bearing pivot boss.
Another similar class was the M&StL class G-1 ten-wheeler built by Schenectady in 1900-01, numbered 100-103. They have several distinctive features such as a shotgun stack that narrows until about 1/3 the height, and then widens. Other features include driver fenders, extended piston rods, rounded edges on the cylinder jackets, and a long wooden pilot with a fold-up coupler. The looked like a racehorse.
For as simple and primitive as they were, most 1870-1880 era 4-4-0s were quite handsome. Yet most of them were eventually reworked by their owners to take the screens out of the stacks and put them into the smokebox, which was elongated in the process. For the most part, in my opinion, this rework resulted in some of the most ungainly looking locomotives ever.
Another beauty was the Burlington & Missouri River 4-4-2 Class P-2 from Rogers in 1903, with their 84 ½” drivers. They also feature inside piston valves, spoked pony and trailing wheels, a horizontally slatted pilot, and a fold up front coupler. These engines and a discussion of their speed records are detailed in Burlington Bulletin No. 44.
Juniatha As for design of heavy ramp lugging engines - what do you say about the Triplex engines and Henderson's further imaginations of Quadruplex and Quintuplex ? = J =
As for design of heavy ramp lugging engines - what do you say about the Triplex engines and Henderson's further imaginations of Quadruplex and Quintuplex ?
= J =
Incidentally, at the time that the Virginian was attempting to use its triplex, my mother was staying with an aunt who lived about ten miles north of the Virginian, and she said that you feel the ground shake whenever the engine passed by.
No problem with me – it's actually Big Jim's thread and if the boys now want to go drag racing a Compound Malley against a Northern I'm prepared to wave the flag on asking ( I was only wondering why still use my head line ? in the end that's a question of detail , though ) . Preferably though , I'd propose not to go on just a quarter mile but on 4 miles . Question : will the contest be held including burnout ? (well , I think .. rather without)
Seriously : each were engines designed for a purpose and they were good at their respective jobs – that’s what counted for the RRs . Big Jim , to read the N&W had planned on a simple expansion 2-8-8-2 really surprises me . I wonder why , in view of huge lp cylinder volume , no RR came up with a three cylinder lp unit ? Now , don’t say it wasn’t feasible in a Mallet – not on the rear unit , that’s right , but on the front unit with the boiler front end further back than cylinders it might have been given some thought . Question : what to do about middle cylinder valve gear – Gresley / Alco variation derived or individual valve gear for each cylinder ..? It seems during the ‘oil-crisis’ in 1973 A Chapelon was addressed by some American group (?) on what specifications a Super Power 4-8-8-4 should take and he proposed a four cylinder lp front unit with two hp cylinder on the rigid unit . The concept was envisaged to produce up to 16000 ihp …
And then there was the Triplex – an idea on which I had spent some thought on questions of steam piping layout , throttles handling and put up a sketch myself , as soon as I had seen a photograph and read a little of it – but that was at an early age and I guess is quite another story …
Contemplative regards
With each post we seem to be wanting to talk about something other than what Juniatha intended. Perhaps someone interested in debating these other topics could start a thread?
This thread has gone off in several different directions, and I'll just offer a couple of quick comments as an outsider.
On the discussion of engines synching, listen carefully to the video of 3985 loaded with the diesels in dynamic braking. It sounds to me like the engines are in synch until 3:06 when there is a slip, but at 3:14 they are back in synch and remain so as they cross in front of us. I had never realized that this happened in articulated engines. Thanks for that link; I'm still trying to get the tingling in my spine to settle down.
As for the front engine's tendency to be the first to slip, I always thought track condition had an influence--the front engine cleans the track and warms it up a little.
_____________
"A stranger's just a friend you ain't met yet." --- Dave Gardner
>> E-hm - pardon me , not intending to disturb in this 2-8-8-2 compound against 4-8-4 s.e. issue , may I ask why do you keep using my caption ?
Threads drift, it happens.
Union Pacific 4-12-2 #9000
John
E-hm - pardon me , not intending to disturb in this 2-8-8-2 compound against 4-8-4 s.e. issue , may I ask why do you keep using my caption ?
Maybe someone (not me) can post a picture of one of these ?
BigJim Yeah, well draging coal around all day is not all the Y's did. They were also used in through freight service. One of my mentors when asked said 63mph was about as fast as you would want to run one. After that things started getting a little shakey.
Yeah, well draging coal around all day is not all the Y's did. They were also used in through freight service. One of my mentors when asked said 63mph was about as fast as you would want to run one. After that things started getting a little shakey.
GP40-2 Y6b engine weight was 612,000 lbs. A NYC S1a engine weight was 471,000 lbs. That makes the Y6b 141,000 lbs heavier than the S1a,
Y6b engine weight was 612,000 lbs. A NYC S1a engine weight was 471,000 lbs. That makes the Y6b 141,000 lbs heavier than the S1a,
How do you define "out perform"? Initial starting tractive effort? Then perhaps you may have a case for the Y6b. Pulling tonnage at 45-55 mph? Then that is a different story. A Y6b would be running out of breath at those speeds,
It's too bad so many people, such as yourself, are so hung up on the myth thinking the Y6's couldn't stretch their legs when they needed to.
But again, we are getting away from the subject of this thread, which just happens to be aesthetics.
You are more than welcome to open up your own thread debating who's better than who so I can ignore it.
BigJim but the Y6 weighed nearly 140,000 lbs more. Closer to 89,000 lbs. but who's counting.
but the Y6 weighed nearly 140,000 lbs more.
Closer to 89,000 lbs. but who's counting.
Y6b engine weight was 612,000 lbs. A NYC S1a engine weight was 471,000 lbs. That makes the Y6b 141,000 lbs heavier than the S1a, but both locomotives produced similar peak HP.
BigJim And we've seen how a Y6 could out perform an Allegheny and a Yellowstone.
And we've seen how a Y6 could out perform an Allegheny and a Yellowstone.
How do you define "out perform"? Initial starting tractive effort? Then perhaps you may have a case for the Y6b. Pulling tonnage at 45-55 mph? Then that is a different story. A Y6b would be running out of breath at those speeds, while an Allegheny or Yellowstone class would be right in the heart of their horsepower curves.
A Y6b may have been the most advanced slow service compound articulated ever made, but their boiler output wasn't even close to a Allegheny or Yellowstone. That really isn't a issue, because the N&W used the Y Class within its design parameters and didn't expect it to be something it wasn't.
I’m afraid , you’ll have to click for full size as it’s essential to see it in 1:1 scale or else the font will not be displayed sharply defined ; I'm not sure if it works , if it doesn't I'll find another method
Juniatha,Once again your sense of style is getting in the way of the ease of reading. This time the background of your data table is a big distraction interfering with the ability to read the fine print.
Hi folks Yes, the wheel treads wore circumferentially uneven . That was a consequence of a steam locomotive’s curve inscription with powered axles rigidly in frame and it’s various disturbing motion while running , caused by reciprocating masses (and thus the more so , the less well balanced the engine unit was) . We’re speaking of 1/32 to 1/16 ins between high and low spot in a worn tire , though – nothing to prompt noticeable extra disturbance nor any consequence to track maintenance . For instance , on Decapod engines wheel flanges on the leading coupled axle wore decidedly faster than those of intermediate coupled axles and to a different lateral pattern , too , because first coupled axle was taking a share in guiding the engine in curve – DR Decapod classes were equipped with Krauss-Helmhotz-truck which combined leading Pony truck with lateral motion on first coupled axle so as to level and dampen peak flange forces while fifth coupled axle was laterally moving to run free of flange contact in wider curves or guide itself in sharp curves . Heavier wear on first coupled axle was because it could not inscribe properly in curve but run with flange contact on the outer rail at an angle to rail , thus tread wear was increased over second , fourth and fifth coupled axles . Because longitudinal oscillation , unbalanced reciprocating masses , all coupled wheels showed circumferentially uneven wear of treads as this action could not go without varying degrees of micro slip . As axle bearings and axle box sliding in pedestals developed play , main drive axle also suffered by rattling under the influence of these unbalanced masses , which was destructive not just to bearings wear but also to tire wear if you think of how that axle changed position 4 times per wheel turn , thereby adopting two counteracting positions not strictly at right angle to longitudinal center line , one forward and one backward stop position within the amount of play . Since the coupled axles all showed different patterns of motion on track with engine running at speed , overall wear of wheel tires differed and engines tended to get non-identical drive wheel diameters by accumulating mileage and this disturbed proper adhesion , additional to disturbing knocking action by play in bearings and axle boxes , all combining to make engine slip easier . The valiant Y-6 compound Mallet : I guess what Big Jim has in mind is grade climbing – there is no doubt Y-6 engines lived up to best standards in very heavy ramp work and did so at relatively economic coal consumption . Yet , as this heavy lugging operation necessarily went along at low speeds , equivalent power output was not as high as with running maximum power at speed , like with an A class 2-6-6-4 at 50 mph . To produce some 7000 – 8000 ihp at 20 mph would have called for multi-unit diesel tractive effort and by default that clearly was beyond limits of any 2 x 8 coupled Articulated – Mallet , Garratt or you name it . As some of the Mallet’s engine mass consisted of unproductive mass inserted just to augment adhesion mass , while tractive effort was improved and this improved heavy lugging capacity on grades , power to construction mass relation of such an engine could no longer compete with engines designed without such dead mass . I have compiled a data table of engine classes here concerned , based on data in literature (in case you might have more precise figures on items , you may want to let me know) . It’s meant to show relations of mass , tractive effort and power output . I’m afraid , you’ll have to click for full size as it’s essential to see it in 1:1 scale or else the font will not be displayed sharply defined ; I'm not sure if it works , if it doesn't I'll find another method (add.: you may press [ctrl] plus run the mouse wheel to enlarge display , not perfect but it helps). As can be seen in line 12 , boilers of Mallets were somewhat less large in relation to engine mass than in rigid frame engines . As boiler design trend went away from searching maximum heating surface by long tubes of small diameters , there is a general decrease of heating surface per ton of engine mass ; still evaporation capacity per ton of engine mass did go up as steaming rates were substantially increased with improved boiler and draughting design . On the other hand , Articulateds provided superior tractive effort – see line 13 – mainly by sheer number of powered wheels ; in the rare case of UP 9000 and Challenger with both engines having twelve coupled wheels , it was largely a matter of larger mass per axle permitted meanwhile and design having specified somewhat stronger cylinder t.e. while the 4-12-2 was said to have been more sure-footed . However , Mallet’s ihp power per ton of locomotive mass was not equivalent to rigid frame types , see line 14 (engine plus tender , since rarely has an engine been seen at work without one) . Line 15 – power to boiler size – would hint somewhat higher specific steam consumption in Mallets , which in fact is a consequence of long steam pipes , however I wouldn’t want to over-rate this item . Line 16 clearly shows power-oriented characteristics of single drive unit types against tractive effort oriented double drive unit types as design progressed . Oh, and while we’re at it – here are some links to you-tube vids to the topic : http://www.youtube.com/watch?v=9alWb5KI5Uo&NR=1 Red headed , erh cab , UP 3985 on road test pulling diesels dynamic braking
Hi folks
Yes, the wheel treads wore circumferentially uneven . That was a consequence of a steam locomotive’s curve inscription with powered axles rigidly in frame and it’s various disturbing motion while running , caused by reciprocating masses (and thus the more so , the less well balanced the engine unit was) . We’re speaking of 1/32 to 1/16 ins between high and low spot in a worn tire , though – nothing to prompt noticeable extra disturbance nor any consequence to track maintenance . For instance , on Decapod engines wheel flanges on the leading coupled axle wore decidedly faster than those of intermediate coupled axles and to a different lateral pattern , too , because first coupled axle was taking a share in guiding the engine in curve – DR Decapod classes were equipped with Krauss-Helmhotz-truck which combined leading Pony truck with lateral motion on first coupled axle so as to level and dampen peak flange forces while fifth coupled axle was laterally moving to run free of flange contact in wider curves or guide itself in sharp curves . Heavier wear on first coupled axle was because it could not inscribe properly in curve but run with flange contact on the outer rail at an angle to rail , thus tread wear was increased over second , fourth and fifth coupled axles .
Because longitudinal oscillation , unbalanced reciprocating masses , all coupled wheels showed circumferentially uneven wear of treads as this action could not go without varying degrees of micro slip . As axle bearings and axle box sliding in pedestals developed play , main drive axle also suffered by rattling under the influence of these unbalanced masses , which was destructive not just to bearings wear but also to tire wear if you think of how that axle changed position 4 times per wheel turn , thereby adopting two counteracting positions not strictly at right angle to longitudinal center line , one forward and one backward stop position within the amount of play .
Since the coupled axles all showed different patterns of motion on track with engine running at speed , overall wear of wheel tires differed and engines tended to get non-identical drive wheel diameters by accumulating mileage and this disturbed proper adhesion , additional to disturbing knocking action by play in bearings and axle boxes , all combining to make engine slip easier .
The valiant Y-6 compound Mallet :
I guess what Big Jim has in mind is grade climbing – there is no doubt Y-6 engines lived up to best standards in very heavy ramp work and did so at relatively economic coal consumption . Yet , as this heavy lugging operation necessarily went along at low speeds , equivalent power output was not as high as with running maximum power at speed , like with an A class 2-6-6-4 at 50 mph . To produce some 7000 – 8000 ihp at 20 mph would have called for multi-unit diesel tractive effort and by default that clearly was beyond limits of any 2 x 8 coupled Articulated – Mallet , Garratt or you name it . As some of the Mallet’s engine mass consisted of unproductive mass inserted just to augment adhesion mass , while tractive effort was improved and this improved heavy lugging capacity on grades , power to construction mass relation of such an engine could no longer compete with engines designed without such dead mass .
I have compiled a data table of engine classes here concerned , based on data in literature (in case you might have more precise figures on items , you may want to let me know) . It’s meant to show relations of mass , tractive effort and power output . I’m afraid , you’ll have to click for full size as it’s essential to see it in 1:1 scale or else the font will not be displayed sharply defined ; I'm not sure if it works , if it doesn't I'll find another method (add.: you may press [ctrl] plus run the mouse wheel to enlarge display , not perfect but it helps). As can be seen in line 12 , boilers of Mallets were somewhat less large in relation to engine mass than in rigid frame engines . As boiler design trend went away from searching maximum heating surface by long tubes of small diameters , there is a general decrease of heating surface per ton of engine mass ; still evaporation capacity per ton of engine mass did go up as steaming rates were substantially increased with improved boiler and draughting design . On the other hand , Articulateds provided superior tractive effort – see line 13 – mainly by sheer number of powered wheels ; in the rare case of UP 9000 and Challenger with both engines having twelve coupled wheels , it was largely a matter of larger mass per axle permitted meanwhile and design having specified somewhat stronger cylinder t.e. while the 4-12-2 was said to have been more sure-footed . However , Mallet’s ihp power per ton of locomotive mass was not equivalent to rigid frame types , see line 14 (engine plus tender , since rarely has an engine been seen at work without one) . Line 15 – power to boiler size – would hint somewhat higher specific steam consumption in Mallets , which in fact is a consequence of long steam pipes , however I wouldn’t want to over-rate this item . Line 16 clearly shows power-oriented characteristics of single drive unit types against tractive effort oriented double drive unit types as design progressed .
Oh, and while we’re at it – here are some links to you-tube vids to the topic :
http://www.youtube.com/watch?v=9alWb5KI5Uo&NR=1
Red headed , erh cab , UP 3985 on road test pulling diesels dynamic braking
from the video : 3985 pulling against dynamic braking with drive sets almost perfectly synchronized
http://www.youtube.com/watch?v=vCaZgOOjNKE&feature=related
UP 3985 after rebuilding , fitted with double Lempor- starting with diesel dyn braking ;
pacing at speed – just for the grand splendor of it / starting with drive sets at about 120 ° phases
from the video : starting with drive sets at some 120 °
Challenger 3985 ready to take the challenges again test run w DDA40X dyn brake diesel – pacing at speed : 1:48 the 4-6-6-4 riding like a Cadillac 3:00 I can see a difference in throw-out of gas/steam mixture 7:16 accelerating w drive sets at right angle – double show with double drive sets
Challenger 3985 ready to take the challenges again test run w DDA40X dyn brake diesel – pacing at speed :
1:48 the 4-6-6-4 riding like a Cadillac
3:00 I can see a difference in throw-out of gas/steam mixture
7:16 accelerating w drive sets at right angle – double show with double drive sets
from the video : starting with drive sets at right angle - four beats per revolution of wheels and a splendid sight
http://www.youtube.com/watch?v=9LsuNWjRaAo&feature=related
combine the sound of cars from this with accelerating Challenger
http://www.youtube.com/watch?v=x8f9VFlNyDQ&feature=related
Big Boy in regular traffic – 2:40 starting out w heavy freight , hear synchronized beats
http://www.youtube.com/watch?v=cl22e1yQ7ZQ&feature=related
amazing : double heading a coal train two little BigBoys have synchronized beats with each other – or so it sounds
http://www.youtube.com/watch?v=QhQMqKl38wU&feature=related
G-scale BigBoy with looong train – 4:00 “slowly accelerating the cars …”
slowly ?? considering the 152 cars train I guess that was a start like on Sunday at the drag strip , synchrocooperised or not !
Regards Juniatha
Regards
July 8th :
I deleted the table because the format is too large (1000 px x 1588 px) , automatically resized
to reduced scale the font gets blurred . If you want a clear 1:1 copy.jpg you may write a message to me .
Closer to 89,000 lbs. but who's counting. And we've seen how a Y6 could out perform an Allegheny and a Yellowstone. There are many ways to express HP ratings in steam locomotives depending on how one wants to spin the doctor.
Comparing other roads mallet locomotives to the rigid frame locos, I will concede Juniatha should be correct. It's just that the N&W Y6 wasn't just anyones old mallet type. Unlike other roads who chose not to develop their locos, the N&W developed the Y class until the very end and what a mallet it was!
And btw, I hever heard of a Y6 (or Class A / J) ever running out of steam so their boilers must be making more than enough steam.
BigJim GP40-2: How? By being several percentage points higher in efficiency than your 4-8-4.
GP40-2: How?
How?
By being several percentage points higher in efficiency than your 4-8-4.
Juniatha's statement was when comparing total engine weight, a big articulated did not produce as much HP per pound as a rigid frame steam locomotive. The minor increase in efficiency that a compound Y6 may or may not have produced has nothing to do with that statement. The fact is, a Y6's boiler was quite small for an articulated design, about the size of a large 4-8-4, and produced similar peak HP. The Allegheny and Yellowstone Class boilers were much larger and could produce much more steam per hour. The difference between the Y6 and a large 4-8-4 was the Y6 produced peak HP at 20 to 25 mph, while the typical Superpower 4-8-4 would produce peak HP around 60 mph. Peak HP was similar, but the Y6 weighed nearly 140,000 lbs more.
A similar comparison would be to a heavily ballasted 2000 HP SD38 and a relatively light 4200 HP P42DC. The P42DC is producing much more power per pound of locomotive weight compared to the SD38.
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