I submit the VGN Class AE 2-10-10-2's These ten locomotives were built in 1918 by ALCO for the Virginian Railway. Overall width was 144 inches, so they were delivered without their cabs and the front, low pressure cylinders and were assembled after arrival. The 48-inch low pressure cylinders (on 90-inch centers) were the largest on any US locomotive; the cylinders had to be inclined a few degrees to provide clearance.[1] The boiler was also the largest diameter of any locomotive; Railway Mech Engnr says "the outside diameter of the largest course is 112 7/8 in." but the drawing shows 118-1/2 inches diameter at the rear tube sheet.
This class were compound Mallet locomotives: as well as being articulated between the forward, swinging engine unit and the rear fixed one, they were compound locomotives. The rear, high pressure cylinders exhausted their steam into the huge front cylinders. Like many compound locomotives, they could be operated in simple mode for starting; reduced-pressure steam could be sent straight from the boiler to the front cylinders at low speed, for maximum tractive effort.
Calculated in the usual way (assuming equal tractive effort from the two engines and mean effective pressure adding up to 0.85 times boiler pressure) the tractive effort was 135,200 lb in compound; in the US, compound Mallets were credited with 20% more tractive effort in simple mode, or 162,200 lb for the Virginian locomotives.
Unlike some other giant locomotives of the period, the immense boilers could generate enough steam to make them a success on the slow (8 mph or 13 km/h) coal trains for which they were built. They remained in service until the 1940s and could be called the ultimate drag era locomotive.[
They were designed primarily for narrow-gauge operations. US railroads did look at the concept.... however Garretts lose tractive effort as they burn fuel, since they don't carry their fuel in a separate tender. Railroads here also didn't have the design and size constraints faced by railroads in many places--which allowed them to evolve into brute-force machines, much in the manner rivers require small craft of a couple thousand tons maximum and the open ocean allows 500,000 ton oil tankers and 120,000 ton aircraft carriers. (Million ton oil tankers have been designed and planned, but never built--such vehicles would be so large as to be directly affected by the Earth's rotation.) US articulateds kept more consistent tractive effort because their fuel was kept in a separate tender, allowing the locomotive proper to be much heavier and longer (in addition to wider owing to a wider gauge). Mexico had some narrow gauge 0-4-4-0s that were quite endearing creatures. The forward driver bogie was inside frame and the rear driver bogie was outside frame. They carried 2-axle tenders behind them.
I have also found Garrets to be pretty homely, but what a brilliant concept in locomotive design! No tender to lug around, a suspended boiler with no constraints on the firebox and weight distributed over a long span so as not to strain lightly built roadbeds. Gotta wonder why it was never exploited in the US. As for those German 0-4-4-0T's, they are so ugly that they are cute! But give me those 2-10-2T's any day!
For that matter..... not all articulateds were steam.... I'll bet someone can guess my favorite articulated diesel, my favorite electrics were the IT class C and D motors.
It's hard to go wrong for style..... though my personal favorites are the 2-10-10-2 of VGN and AT&SF. For those that have survived to the present day..... the Y6b would be most practical to restore for operation. Lighter on rail, more compact overall than the others, and well-suited to the occasional back-up more and tight-curvature track it might need to use on occasion. Big Boys were every bit as heavy (or close enough, or heavier) to the Allegheny.... Frankly, it'd be lovely to see all of them operate again.
Well, I kinda like the color...
erikemSounds like something that would appear on S. Berliners Apocrypha website, an extension of the Garret "Bigger Boy" and "Biggest Boy". Doug Self's "Loco Locomotives" website referred to the latter as Hexaplex Delurium.
Strange you should mention that. Go to 'Guest Apocrypha' on that site...
(The class G -- that was real, for a while anyway... ;-} )
Overmod If I could find my old drawings of the 4-8-8-8-8-4+4-8-8-8-8-4 Garratt, I bet you'd change your mind about them! ;-}
If I could find my old drawings of the 4-8-8-8-8-4+4-8-8-8-8-4 Garratt, I bet you'd change your mind about them! ;-}
Sounds like something that would appear on S. Berliners Apocrypha website, an extension of the Garret "Bigger Boy" and "Biggest Boy". Doug Self's "Loco Locomotives" website referred to the latter as Hexaplex Delurium.
- Erik
Model of the AC38 (with some poetic license in the striping) here:
Garratt 38 thread
Overmod, I'd have to say any Garrett I've seen in pictures I considered ugly. The AC38, you've got me there, I'm not familiar with what that is.
And for all you Garrett fans out there, don't take this personally. If you like the things, that's cool with me, I won't say you're wrong.
Firelock76 Garretts? I don't know, those machines leave me cold. Yes, I fully acknowledge their efficiency, adaptability, and ability, but they're so blamed ugly!
Garretts? I don't know, those machines leave me cold. Yes, I fully acknowledge their efficiency, adaptability, and ability, but they're so blamed ugly!
Are you claiming that this applies to the production Algerian Garratts or the design for the AC38?
Well, I guess the Garretts are living proof the saying "If it looks good, it'll run good" isn't necessarily true all the time.
I didn't say they were beautiful, hey they're not the Dreyfus Hudsons of the NYC, but they have a certain charm all their own.
54light15 Garratts! I love 'em! I wish someone made one in model form but I've never sen one in any scale.
Garratts! I love 'em! I wish someone made one in model form but I've never sen one in any scale.
Dear God, there are many! (Perhaps not easy to find, but they were made!) There is a very good model now available of the AD60 in Australia. I remember a Model Railroader discussion of one of the African Garratt kits -- probably sometime in the early Seventies; that was, if I recall correctly, a white-metal kit.
Everything I remember seeing was HO, but I'll bet a hat there are others.
do to the way Garrets were build I would think it would not be impossible to kitbash one.
Back to the real thing. I would settle for a big articulated dummy engine,restored to roll but pushed by a Diesel. Not ideal,but better than nothing.
Since this consideration has now stepped outside of the United States, I would offer these articulateds for your consideration: EAR 59-class 4-8-2+2-8-4 and NSWGR 60-class 4-8-4+4-8-4 Garratts.
I know I love those little guys! Most successful? Yeah, I'd have to agree. There was one at the DB museum at Nuremberg in 2004 sitting on a short length of track. I visited the museum again two years later and found out it was taken away to be restored and run. There's quite a few of them running on the NG lines in eastern Germany; I've been to most of them and want to go back. They're the reason I want to sell my N scale stuff and build an HO NG layout, based on what I saw over there.
Maybe those little German 0-4-4-0T's aren't the biggest of articulateds, or the most famous, or the best looking, but considering their longevity they're probably the most successful of all articulateds.
"Blessed' be the meek, for they shall inherit the Earth!"
I don't pretend that it's the best articulated, but in Germany there are these spiffy little 0-4-4-0T Meyenberg locomotives, little jobbies that run on the Harz narrow gauge and many others. I'd post a picture if I could but have a look at the Harz films and you'll see. I was at a NG railway near Trier a few years ago and in the back of a shed was one, sitting there like a 53 Corvette, just waiting to be restored.
efftenxrfe Just an aside concerning my remarks about the AC9 and that size does matter. A couple of posts indicated that it was because the firebox truck was the leading truck that made it proportionately different. Well, the AC9 was the only class that was not a "Back-up Malle(y)." AC9's were the....NP Yellowstones, DMIR's 2-8+8-4's....the third conventional 2-8+8-4's. Maybe the last? Nomenclature and characteristics weren't paramount to SP's eng. class identities. A GS4 spotting an industry on a branch....but SP 4449 was a General Service (GS) and like-wise, (AC) followed standing in for Articulated Consolidation, logically a 2-8+8-2, as in PRR's GG1. Historically recollected, early on the family of Cab-forwards included 2-8+8-2's, the justifying factor to let SP confuse people to confuse wheel arrangements.
Just an aside concerning my remarks about the AC9 and that size does matter.
A couple of posts indicated that it was because the firebox truck was the leading truck that made it proportionately different.
Well, the AC9 was the only class that was not a "Back-up Malle(y)."
AC9's were the....NP Yellowstones, DMIR's 2-8+8-4's....the third conventional 2-8+8-4's. Maybe the last?
Nomenclature and characteristics weren't paramount to SP's eng. class identities. A GS4 spotting an industry on a branch....but SP 4449 was a General Service (GS) and like-wise, (AC) followed standing in for Articulated Consolidation, logically a 2-8+8-2, as in PRR's GG1.
Historically recollected, early on the family of Cab-forwards included 2-8+8-2's, the justifying factor to let SP confuse people to confuse wheel arrangements.
AC-9s were conventional with the cab in the rear. However, they were built in 1939, and were not the last 2-8-8-4s. The B&O EM-1 was the most modern version of the 2-8-8-4, designed and constructed in 1944-45.
Overmod This is a specious comparison; the Yellowstone, like the various Challengers and the Big Boy, carries its firebox partially over the rear-engine drivers. It might technically be possible to move the boiler and firebox forward, along the general line of a "big 2-8-8-2" but then the weight on drivers (already just about maxed-out on a Yellowstone) might be too extreme, or the swing of the smokebox over the forward engine too extreme. (In defense, air access to the grate might be better with a 2-wheel. trailer... ) The A, on the other hand, like the Allegheny or, in the 2-8-8-4 world the EM-1, has a deep forebox, which gives better combustion efficiency, or a 'lazier' response to draft at high power (much of the "fuel" in a Big Boy was ignited and burned without ever residing on the grate at all... just the opposite of what is desired in a fire for a coal-burning engine...) By the time you get this up to the 135' of the Allegheny, in a deep firebox, you may be talking six-wheel truck, and designs intended to add additional radiant surface (like Lima's proposed Long Compression/double Belpaire eight-coupled engine from 1949) might need six wheels under there, too. On the gripping hand, of course, there's always the argument that the three axles aren't so much needed for weight bearing as to span the greater longitudinal distance under the firebox with less structural difficulty for the truck frame itself... I would argue that it's better in a comparison like this to compare grate area rather than heating surface. GA of a Yellowstone was somewhere around 125 square feet. I'll grant you that there are other efficiency concerns (such as extended surface of a longer chamber, or firebox and chamber syphons) but the tone of that "750 square feet' is more suited to a pissing contest than coherent locomotive discussion. In my opinion, there are too many other variables for you to quote HS numbers as though other factors are not as, or more, significant, even if only discussing the degree to which the firebox overhangs the rear driver.
This is a specious comparison; the Yellowstone, like the various Challengers and the Big Boy, carries its firebox partially over the rear-engine drivers. It might technically be possible to move the boiler and firebox forward, along the general line of a "big 2-8-8-2" but then the weight on drivers (already just about maxed-out on a Yellowstone) might be too extreme, or the swing of the smokebox over the forward engine too extreme. (In defense, air access to the grate might be better with a 2-wheel. trailer... )
The A, on the other hand, like the Allegheny or, in the 2-8-8-4 world the EM-1, has a deep forebox, which gives better combustion efficiency, or a 'lazier' response to draft at high power (much of the "fuel" in a Big Boy was ignited and burned without ever residing on the grate at all... just the opposite of what is desired in a fire for a coal-burning engine...) By the time you get this up to the 135' of the Allegheny, in a deep firebox, you may be talking six-wheel truck, and designs intended to add additional radiant surface (like Lima's proposed Long Compression/double Belpaire eight-coupled engine from 1949) might need six wheels under there, too. On the gripping hand, of course, there's always the argument that the three axles aren't so much needed for weight bearing as to span the greater longitudinal distance under the firebox with less structural difficulty for the truck frame itself...
I would argue that it's better in a comparison like this to compare grate area rather than heating surface. GA of a Yellowstone was somewhere around 125 square feet. I'll grant you that there are other efficiency concerns (such as extended surface of a longer chamber, or firebox and chamber syphons) but the tone of that "750 square feet' is more suited to a pissing contest than coherent locomotive discussion. In my opinion, there are too many other variables for you to quote HS numbers as though other factors are not as, or more, significant, even if only discussing the degree to which the firebox overhangs the rear driver.
Overmod,
I pretty much agree with what you said.
My only point was that the M3/M4 had a very large firebox/cumbustion chamber, about 100 sq.ft. larger than the WP 2-8-8-2 it was reportedly based on. A steam locomotive cab is a light weight, flimsy affair, even in an extended weatherized version. They certainly were not built with the gauge of steel as modern locomotive cabs/short hoods that have FRA mandated collision ratings.
The point being, even with the slighly larger cab, it would not add enough weight to need a 4 wheel trailing truck. It needed the additional trailing axle to help support the long firebox/cumbustion chamber that was cantilevered back past the drive axles.
I have some additional thoughts on the depth of firebox designs and grate area that I will discuss when I have more time.
Paul MilenkovicOn the other hand, the description of how this system promoted smokeless combustion, do you suppose that this was an independent discovery of Porta's Gas Producer Combustion System (the GPCS)?
No.
Keeping the 'heel' and filling the back corners had little to do, overtly, with smoke-free operation. It had to do with maintaining consistent combustion-gas mass flow without opening up spots in the bed, or overheating ash to clinker... things like that. Remember too that some of the heel slides down as the locomotive rides, and this would open up free air spots toward the back of the grate if not attended to, and who has the time to keep checking while firing, calling signals, etc.? (There is an amusing article somewhere on the Web, I think from the old Railroad Magazine, about 'bright college boys' dictating that all locomotives should be fired smoke-free... and what the problems with that approach could be!)
GPCS involves a sealed firebox, with a bare minimum of primary air mixed with steam. This gasifies the coal, rather than combusting it outright, and then the resulting CO and hydrocarbons are burned to produce most of the radiant heat, ostensibly more cleanly and completely. A moment's reflection will tell you what considerations for secondary air (and even tertiary air in some cases) would require in such a system... guns of conventional type NOT being a particularly helpful or healthy solution.
May I humbly suggest that the discussions on (1) firing technique and (2) valve pilot and the like be taken to their own threads? They have little to do with the subject of this post, and the thoughts they contain might be lost to future searchers...
Jim and Paul, I agree that not all printed words amount to the best wisdom found in the real world, and that was made clear to me in a counter-intuitive way in the latest edition of Classic Trains where they talked about the valve pilot. It taught many frustrated engineers how to get the most out of locomotives they swore would never lift a train over a grade where they had failed countless times without helpers. Later, with the valve pilots, they found that they could!
Running any one steam locomotive was at least as much an art as science.
Crandell
I am certainly not as knowlegeable about steam as many posters on this thread, However:
I have read that Yellowtone design was based of the Western Pacific's M-137 class 2-8-8-2s which had even larger fireboxes than the Yellowstones (although the WP engines were oil burners). I have read multiple sources(like this:http://www.steamlocomotive.com/yellowstone/?page=dmir) that state that the longer frame on the Yellowstone was in fact, due to the extra large all- weather cab designed for the harsh winter weather of Minnesota rather than the firebox size.
IINM, there were coal burning 2-8-8-2s that approached the Yellowstones in size and firebox dimensions, the D&RGW L-131s would be an example.
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
BigJim Read "Apex of the Atlantics" and how one engineer discovered how a "heel" helped his fire to an amazing degree. And, this was on a PRR loco without a stoker. It also supported what every steam man has told me. They used the stoker, with the jets turned off, to supply the coal instead of using a shovel.
Read "Apex of the Atlantics" and how one engineer discovered how a "heel" helped his fire to an amazing degree. And, this was on a PRR loco without a stoker. It also supported what every steam man has told me. They used the stoker, with the jets turned off, to supply the coal instead of using a shovel.
Yes, I just got a copy of Apex of the Atlantics and read the part of that one engineer training his firemen to prep the fire starting out.
It may not have been as easy as simply jamming the firebox full of coal. On the other hand, the description of how this system promoted smokeless combustion, do you suppose that this was an independent discovery of Porta's Gas Producer Combustion System (the GPCS)?
I have also seen the local operator of "zoo gauge" steam locomotives stuff their fireboxes with coal and get smoke free operations, but I need to talk to someone in-the-know to find out what they are doing. So maybe the "light and bright" thin firebed is not the optimal system of stoking?
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
Crandall, Operating manuals (and web sites) don't tell you everything, so don't let this web page close your mind. Tricks of the trade are developed over time by the people who work in their chosen arena every day. Putting a heel in the firebox seems to be one of these ( I don't think the NYC or the C&O manuals even tell how this was done). It doesn't mean that coal was stacked to the top of the distributer plate. It is about forming the coal around the bottom in a type of upward slope toward and around the bottom of the distributer plate high enough and in a way that helps shape the way the fire burns. Read "Apex of the Atlantics" and how one engineer discovered how a "heel" helped his fire to an amazing degree. And, this was on a PRR loco without a stoker. It also supported what every steam man has told me. They used the stoker, with the jets turned off, to supply the coal instead of using a shovel. I haven't read my copy of "Set Up Running" in a long time, so, I don't know if he has anything to say on this matter or not. I do know that it is an excellent book, the best I have read on real life experiances on the RR.
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BigJim selector Big Jim, I may be wrong, but so would the person suggesting how to fire an engine with a stoker at this site: http://www.southerncape.co.za/history/transport/railways/locomotives/the_standard_mechanical_stoker_1956.php See the section further down on 'Suggestions to the Fireman", the first warning given. CrandellAnd did you read this above? " Ensure that the portion of the grate under the distributing table is well covered with coal. " Like I said, every steam man I ever worked with (and there were many) said the same thing. You needed a good heel. If I'm not mistaken, there is a passage in "Apex of the Atlantics" that tells of an engineer that did just this and saved a lot of coal over the run or something to that effect.
selector Big Jim, I may be wrong, but so would the person suggesting how to fire an engine with a stoker at this site: http://www.southerncape.co.za/history/transport/railways/locomotives/the_standard_mechanical_stoker_1956.php See the section further down on 'Suggestions to the Fireman", the first warning given. Crandell
Big Jim, I may be wrong, but so would the person suggesting how to fire an engine with a stoker at this site:
http://www.southerncape.co.za/history/transport/railways/locomotives/the_standard_mechanical_stoker_1956.php
See the section further down on 'Suggestions to the Fireman", the first warning given.
If I'm not mistaken, there is a passage in "Apex of the Atlantics" that tells of an engineer that did just this and saved a lot of coal over the run or something to that effect.
Okay, this sounds like a terminology thing. I would agree that the area directly under and close to the distributor plate must be addressed. When first starting out, it must have a suitable covering of the grate area in question to ensure no holes. If you and others call that the heel, yes, it must be covered. As the site I quoted said, do not allow that same area to get heavily piled because it causes inordinate heat stress to at least one design of distributor plate, or more. I would guess the flues handling the gases from that area would be differentially heated as well, hardly ever a good thing for a flue sheet.
Getting a "good heel"? Sure, if it means what he said about ensuring adequate coverage. He goes on to caution about negligent piling and inattention to that area later.
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