The 1925 Super-Garratt Patent 230,888 design for standard gauge gives a taste of what might have been had a Garratt design been able to take advantage of the more generous American loading gauge clearences and axle loads. I say taste because even this design is certainly not stretching the limits of what could be done with a Garratt on US railroads. Nevertheless, it's an impressive engine.
It's a 2-6-6-2+2-6-6-2 with 160 sq ft grate, 585 sq ft firebox heating surface, 7482 q ft of combined evaporative heating surface and 1818 sq ft of superheating surface. Boiler pressure is somewhat low at ~177 psi. It's eight 19" x 26" cylinders look very manageble relative to the mass flow of the boiler.
Another Garratt I would have like to have seen would have been some the of express passanger 4-6-2+2-6-4 proposals in Britain. One was a six cylinder compound with 81 inch drivers. In Britain the Garratt locomotives that did exist on the standard gauge system such as the LNER U1 2-8-0+0-8-2 and LMS 2-6-0+0-6-2 certainly had among the largest boilers on the network, having boiler dimensions that would be difficult to achieve with any conventional stephensonian design on the British loading gauge.
Incidentally you should at least consider better circulation systems than Johnson was assuming --ideally combined with more positive steam separation. The Cunningham system alone is supposed to be good for ~12% greater effective mass flow through reduction of critical DNB even in an otherwise-unmodified Stephenson firebox; the more logical solution has (for a long time) been to adapt the Lamont forced-circulation water construction (where the water is circulated through the tubes at something like 6x the demanded mass flow of steam, for a nearly-trivial pumping power since there is little pressure-head difference from hot well through to steam-separator input, perhaps on the order of 10hp for one this size). The entire circulating mass goes through baffled centrifugal separation (the power for which is provided 'free' as part of the circulation pump operation) -- steam goes up, water goes down, very little 'priming' action is in a vector that would produce, let alone facilitate, carryover. It is much easier to size and package a steam generator like this on a cradle essentially offering the clearances of a depressed-center flatcar than to try it atop a fixed or hinged set of equalized drivers...
L-105... you end up with the Union Pacific 4884-1 Big Boy boiler having an evaporative capacity of ~ 101,000 lbs/hr.
In practice, you would use what I said: a boiler with lagged shell right out to the applicable clearance, set low enough in the cradle to permit proper steam separation with the whole of the convection boiler full of tubes/flies like a HRSG. We could niggle about what proportion of the space under the cradle is devoted to water tankage (a la Union Garratt) vs. economizer and air preheaters vs. practical 'ashaveying' -- the point being that you aren't limited to the silly dimensional and design restrictions of a high-firebox engine essentially using partial pulverized-fuel firing of low average heat content.
Also this 4-8-8-4+4-8-8-4 [double Big Boy] Garratt would then require a water capacity of perhaps 45,000 - 50,000 gallons, unless the engine is intended to stop for water more frequently.
Read my points above concerning water rate and range, then look at why the PRR V1 turbine was cancelled (and not revived after the Bowes drive made it practical to operate). The situation becomes worse rather than better if you try to ameliorate this with some form of condensing: you're basically having to dissipate some large proportion of the heat from that fire on your grates at similar rate to its generation. Even net of all (considerable!) losses this is a losing exercise. The 'best' solution is to use greywater from, say, sewage treatment plants to spray on the outside of your condensers to preserve the expensive treated feedwater within... but now you have two tankage systems each with its own tinkering quotient.
The correct answer, then as now, was horsepower from gas engines, which don't care about throwing away their working fluid. This was recognized as early as the 1880s in the railroad trade press, and this led to some real design whoppers like the German Thermolokomotive of 1912, but it was arguably wholly achievable no later than the early 567s or 408s from a practical standpoint, and via GM financing access (Westinghouse, then controlling Baldwin, seems to have dropped this rather obvious ball) from the economic side.
Had there not been a WWII leaving railroads relatively flush with cash that had to be 'used or lost' there might have been more expedients to provide "enhanced" water for better operations. The N&W operation of 15,000-ton trains out of Williamson as described by Ed King is one example of what's involved to make the trick work; the prospective LV duplex 4-4-6-4 diagram clearly show four little additional axles, almost certainly for additional cistern capability that would allow the engines to be turned.
So this 4-8-8-4+4-8-8-4 Garratt Big Boy that was proposed, in simple articulated form in order to supply eight 24” x 32” big boy cylinders, you’re going to be needing a boiler with an evaporative capacity of around 200,000 lbs/hr of steam. If we take Ralph Johnson’s suggested value of 80lbs of steam evaporated per sq ft of direct heating surface, and apply a corrected indirect heating surface factor accounting for tube length (in this case 22 ft), you end up with the Union Pacific 4884-1 Big Boy boiler having an evaporative capacity of ~ 101,000 lbs/hr. Also this 4-8-8-4+4-8-8-4 big boy Garratt would then require a water capacity of perhaps 45,000 - 50,000 gallons, unless the engine is intended to stop for water more frequently.
[quote user="Flintlock76"]There was a Texas oil millionaire named Connie Edwards who had a hanger full of Spanish-built Messerschmitts, if you've seen the movie "Battle of Britain" you've seen the planes.
I found a video of Connie and his Spanish Messerschmitts. Very interesting if you're into Warbirds, if not, don't bother.
https://www.youtube.com/watch?v=Hzeux7ZfFuQ
L-105This 2-8-8-6 configuration I've seen mentioned in other topics before. The 6 wheel trailing truck implies the firebox is situated entirely over the trailing axles much like the C&O H-8 2-6-6-6 (correct me if I'm wrong), and is thus situated further back compared to a firebox partially situated on top of the drivers.
In large firebox design you want to increase the length of the radiant section, which is one of the 'secrets' of the deep firebox with arch (and arch circulators). Remember this is luminous carbon flame, not just hot transparent gas, so emitted black body radiation can be absorbed by the (black at saturation temp for boiler pressure) inner box and chamber liner at the 4th power of temperature. This implies that average TOF from above the grate through to the rear tubesheet gives complete combustion right down to a couple inches into the tubes... at which point the gas will be at less than atmospheric pressure.
Note that the 'six wheel truck' does not necessarily give you 'higher horsepower'. There is a fairly hard limit of under 8000hp on a practical single-unit locomotive, and it is set by water rate and useful range; you may note that both the PRR Q2 boiler and its development on the V1 turbine were quite happy with 4-wheel support trucks on a railroad with lower permissible axle load than C&O, both these engines producing more horsepower at peak than an Allegheny, so we look a bit 'elsewhere' to account for the three axles. In my opinion they bear the extra weight of the syphons, etc., in the enlarged grate area, rather than permit a "larger" grate that makes more steam from water you can't economically carry. (The extra axle messes with the ashpan arrangements too.)
In a real-world situation, though, it's more likely important to accommodate cheaper and sometimes poorly-classified coal. So the larger grate and firebox is now provided not to increase the steam generation in absolute terms, but to facilitate the engine's rated hp under suboptimal conditions ... often with less or 'lazier' firing that gives lower thermal stresses in the firebox. This is the predominant justification for three axles' worth of weight.
In order to accomplish this with the shallower Challenger firebox, the grate must be longer and the radiant section longer. This is accommodated by carrying some of the weight on the rear driver pairs, equalizing through to the forward engine as Alco's "patented" arrangement will do. Problem here is that to get equivalent heat release and more important radiant uptake you either have to limit TOF (meaning lower gas speed to get full combustion, a limitation) or arrange to have a considerable volume of fuel ignited and burned almost in the manner of a heavy-oil burner. That's nifty for Big Boys that burn cheap proprietary subbituminous and run out where there is little for cinders on a grand scale to damage...
So in this imagined "2-8-8-6" design, how long are the tubes and flues meant to be? (given that the H-8 was already at the upper end with 23' long tubes).
23' is probably too long for practical elements, which ain't gonna be type E on an articulated when it isn't all-out wartime. So 20 to 22 feet is likely to be the sweet spot here, with certain other parameters determining how much of the shell you can actually populate with tubes, flues, and elements.
At this point you have a reasonable idea of how long your steam-generation system up to the front tubeplate and superheated header will be, and what the dimensions if the oresumably four-nozzle front end and exhaust tracting would be. That in turn will get you iteratively into weight calculations, which were 'tedious' for Johnson but much easier in principle now.
... as Ralph Johnson also mentions, the more heat absorbed in the firebox, the less is available for superheating in the tubes.
I believe the Baltimore & Ohio EM-1 had the longest combustion chamber (I could be wrong), although I don't know its precise length.
Keep in mind that the EM-1 is not representative of the kind of locomotive represented by a 2-8-8-6 (let alone a performance-based simple-articulated Garratt). It is a remarkably small locomotive as 16-drivered engines go, and of restricted vertical loading gage, so while its proportion of firebox to chamber may measure large, in absolute terms of combustion integrity it may not be a 'representative' guide in feet and inches for a larger locomotive.
Flintlock76 4,000 pieces? My hat's off to him, he's got more patience than I've got! Stunning project though, if it was any bigger he could ride it!
4,000 pieces? My hat's off to him, he's got more patience than I've got!
Stunning project though, if it was any bigger he could ride it!
There are A LOT of mind blowing models on that forum. Check out this Hood:
http://www.papermodelers.com/forum/ships-watercraft/42729-hms-hood-28.html
Trains, trains, wonderful trains. The more you get, the more you toot!
Overmodand a truly practical version would have been a 2-8-8-6
This 2-8-8-6 configuration I've seen mentioned in other topics before. The 6 wheel trailing truck implies the firebox is situated entirely over the trailing axles much like the C&O H-8 2-6-6-6 (correct me if I'm wrong), and is thus situated further back compared to a firebox partially situated on top of the drivers. So in this imagined "2-8-8-6" design, how long are the tubes and flues meant to be? (given that the H-8 was already at the upper end with 23' long tubes). I'd expect the length to be made up with a very long combustion chamber, but how long? Now I know both Ralph Johnson's The Steam Locomotive and a Mechanical Advisory Committee report of 1935 praises the combustion chamber and offer few caveats (it lowers the surface to volume ratio of the firebox, increases direct heating surface area and can be used to make up extra boiler length to permit practical tube lengths). However, as Ralph Johnson also mentions, the more heat absorbed in the firebox, the less is available for superheating in the tubes. Therefore, just how long can a combustion chamber practically be?
I believe the Baltimore & Ohio EM-1 had the longest combustion chamber (I could be wrong), although I don't know its precise length. Does anyone know what The B&O EM-1 maximum outer boiler diameter and tube length were?
Flintlock764,000 pieces? My hat's off to him, he's got more patience than I've got!
It's only 70 bucks and change from Betexa, too. Buy two and you can make your own 'Mallet-Garratt' for display... if you have a wall long enough!
We on the steam_tech group took a leaf from the Spartacist playbook and made it a point to ALWAYS correct misspellings of Herb Garratt's name. It is a matter of principle, not Writing-to-Read local option. I got one former poster here upset by making the claim a bit too forcefully, thinking that he would recognize the tongue-in-cheekiness of it... thinking wrongly, as it turned out.
Keep in mind that Garrett is a famous name in United Stated practice in a number of respects, turbocharging in particular, so there is little surprise the spelling looks familiar. It's just not the right spelling of the locomotive inventor, just as the spelling of the hamburger chain isn't correct for wanswheel's IRL identity...
I chuckle at this very-large-Garratt business in part because I designed one of the things, complete with the necessary alternate history that would justify building and operating a fleet of them. The elevation drawing occupied pride of place in my high school's English AP classroom... until it was STOLEN a couple of years later; it is interesting to think that someone out there still has all 14-odd feet of it for potential rediscovery.
We need to preface the discussion by noting that the Triplexes were not exactly 'failures' of necessity; even had they been given an appropriately-proportioned deep firebox and chamber, and a proper multinozzle front-end arrangement, they would have succeeded in sustaining 'drag' operations greater than the draft gear of the day would likely have tolerated for long. Even adapting a Challenger-style arrangement would likely have worked. The arrangements for water distribution for adhesion that work on Garratts just as fuel distribution for balance worked on Concordes would 'as nicely' work for motor tenders... or extended forward engines. There are some issues with the steam piping that B-P never really solved... and that Alco might not have wholly figured out by themselves... but I think we can safely say Lima did, and their work was no secret by the mid-Forties when a Garratt became the 'next logical step' for big, fast four-engine articulateds. Which, if they failed, would not have done so for any perceived lack of steam, or excess required combustion as on the UP 4000s...
One of the official 'pravdas' was that the cost of the B-P license (which as I recall was in the $500 range, the exact terms bring in that Trains double-Garratt article that was my inspiration) was a major reason no Garratt was built here. That may be true up to double-eight-coupled size, but anything much larger than a 4-8-8-4 (and a truly practical version would have been a 2-8-8-6 but just as dead-end a solution) would have benefited far more than that from some of the unique if dotty-appearing features of the Garratt configuration... especially in the East.
Overmod New horizons: Sam misspells 'Garratt' and then has the temerity to criticize misspelling it later in the same post. Alco of course wouldn't have proposed a 'Mallet-Garratt' because that would imply compound working; in any case that was Beyer-Peacock's idea in the mid-Thirties (which I remembered being covered in Trains, with a very funny cartoon later in the issue showing the thing negotiating double crossovers). About the largest thing they contemplated was the equivalent of double 'Mikado-and-a-half' or 2-6+6-2 (as Le Massena would quote Wiener) - Note that this is very likely as much single-unit power in a scaled-up simple-articulated version as a single boiler ought to be made to produce; compare the actual HP curve of the Big Boy with its Challenger-style firebox to that of an Allegheny. You would use some conbination of antislip systems in practice but those are trivial to implement. For a large standard-gauge engine the boiler dimensions involve the 'best' of three worlds within typical Eastern loading-gage limits: a deep firebox without truck structure under the grate and involving ash handling; a greater number of tubes and flues in the larger convection-section diameter but still limited in length to ~20'; good vertical steam separation to permit higher filling of the convection boiler and higher mass flow of generated steam without priming and carryover problems. I think it is likely that a large 'North American' Garratt would have extensive economization a la Franco-Crosti, probably carried in the cradle structure under the convection section, together with Cunningham-like circulation and some form of combustion-air preheat. The principal issue with a weaponized double-Big-Boy (which you will notice is already 'overkill' for North American practice, 2-8+8-2 with high-speed pony trucks doing the necessary guiding jobs just fine, weight management becoming a critical consideration) is very similar to Chapelon's "improved" Big Boy of 10,500-odd ihp. That being that it is new horizons in inflexibility, combined with some new maintenance concerns. At this point in time there were still 'consist limits' on a train practically handled with steam power, while you still lose all the locomotive when any part of it goes down (there are theoretical ways to swap out running-gear parts but they are little fun even compared to through-equalized late simple articulateds). All these big single engines had their best use in relatively unrestricted rah-rah wartime... wartime in which diesel production was strategically restricted. Someone with access to contemporary union agreements can figure out how much extra a crew would be paid for engines of corresponding weight, too.
New horizons: Sam misspells 'Garratt' and then has the temerity to criticize misspelling it later in the same post.
Alco of course wouldn't have proposed a 'Mallet-Garratt' because that would imply compound working; in any case that was Beyer-Peacock's idea in the mid-Thirties (which I remembered being covered in Trains, with a very funny cartoon later in the issue showing the thing negotiating double crossovers). About the largest thing they contemplated was the equivalent of double 'Mikado-and-a-half' or 2-6+6-2 (as Le Massena would quote Wiener) -
Note that this is very likely as much single-unit power in a scaled-up simple-articulated version as a single boiler ought to be made to produce; compare the actual HP curve of the Big Boy with its Challenger-style firebox to that of an Allegheny. You would use some conbination of antislip systems in practice but those are trivial to implement.
For a large standard-gauge engine the boiler dimensions involve the 'best' of three worlds within typical Eastern loading-gage limits: a deep firebox without truck structure under the grate and involving ash handling; a greater number of tubes and flues in the larger convection-section diameter but still limited in length to ~20'; good vertical steam separation to permit higher filling of the convection boiler and higher mass flow of generated steam without priming and carryover problems. I think it is likely that a large 'North American' Garratt would have extensive economization a la Franco-Crosti, probably carried in the cradle structure under the convection section, together with Cunningham-like circulation and some form of combustion-air preheat.
The principal issue with a weaponized double-Big-Boy (which you will notice is already 'overkill' for North American practice, 2-8+8-2 with high-speed pony trucks doing the necessary guiding jobs just fine, weight management becoming a critical consideration) is very similar to Chapelon's "improved" Big Boy of 10,500-odd ihp. That being that it is new horizons in inflexibility, combined with some new maintenance concerns. At this point in time there were still 'consist limits' on a train practically handled with steam power, while you still lose all the locomotive when any part of it goes down (there are theoretical ways to swap out running-gear parts but they are little fun even compared to through-equalized late simple articulateds).
All these big single engines had their best use in relatively unrestricted rah-rah wartime... wartime in which diesel production was strategically restricted. Someone with access to contemporary union agreements can figure out how much extra a crew would be paid for engines of corresponding weight, too.
OVERMOD: I am not trying to put you down for your spelling of the name of the man who designed the original BeyerGarratt locomotive....For a number of years, I and apparently, a large number of us[American's?] had spelled it as "Garrett" or "Gerrett" (?).
Until I got deeper into this subject, and after reading may articles; I realized that I was wrong, and had been spelling it incorrectly for quite some time.
In the link I had originally posted re: "Fiery Giant-The story of the BeyerGarrett locomotive" I found this reference to the inventor. Linked @ http://www.theheritageportal.co.za/article/big-fiery-giant-story-beyer-garratt-locomotive
FTL:"... Now what is a Beyer-Garratt locomotive? To start with the name comes from the manufacturer and its inventor, The Beyer part refers to Beyer Peacock and the Garratt to Herbert William Garratt (1864-1913), who approached Beyer Peacock with his rough idea for an articulated steam locomotive. They saw the possibilities and worked on the details and patented the design in 1907..."
One can spell it any way they want...worng or right.. Their choice.
As to the construction of a BeyerGarrett in the size and shape of whet would essentially be a 'double 'Big Boy'.. My intention was never to say it would orshould be constructed into a real world llocomotive. I just indicated that the ALCO Locomotive Company had purchased the rights to build one....As Flintlock76 had pointed out, it would certainly represent a rail 'monster of a locomotive.' My thoughts being, if anyone could operate it it would probably be a Union Pacific.
Would it ,if built, be a similar 'dud' in the manner of the old Erie RR's Triplex?
I have not seen it mentioned, anywhere, that Beyer-Peacock Company ever built a "Garrett' with a mechanical stoker?
Want to see a model of one being constructed of paper in 1:25 scale? http://www.papermodelers.com/forum/railway-related-builds/45544-angraf-kur-87-karamoja.html
A Garratt in a private collection in Texas? You know, I'm really not too surprised. There was a Texas oil millionaire named Connie Edwards who had a hanger full of Spanish-built Messerschmitts, if you've seen the movie "Battle of Britain" you've seen the planes. Whatever became of them I don't know as I believe Connie's passed on by now.
Who knows what else is hiding in barns and hangars down there?
Good luck to that Texan who owns the Garratt, whether he allows visitors or not!
But you know, time keeps marching on. It'll surface on the used locomotive market someday.
Getting back to Connie Edwards, while making "Battle of Britain" he was asked by an aviation reporter what it was like flying one of those Spanish Me-109's. His answer floored the reporter:
"Well, it's kind of like making love to a gorgeous redhead, while your wife is watching you!"
I hope the 'purists' in the crowd will forgive me! The last couple of days; The Beyer-Garrett Locomotive thingy has been driving me crazy
The appearance of the NSWGR #6029 really 'kicked it off' for me. My comparison Thread between the afor-mentioned, Australian Big [4-8-4+4-8-4 ] Garratt Locomotive ,and UPRR BIG BOY [4-8-4]. Got my research brain cells to working. [Thanks to my friend Mike-Wanswheel!].
That tale of a Garratt locomotive in Texas really got me into it! I knew I had seen it, only WHERE? The following link is to a photo of it. [credited on photo]
http://www.sa-transport.co.za/trains/narrow-gauge/ng_info_pictures/ngg13-50_texas_th.JPG
It is a metre gauge Garratt from South Africa [ClassNGG13-#50 ] a 2-6-2+2-6-2
Operating on the PRIVATE ESTATE At Hempstead,Tx. [Special Note: Owner wants no uninvited visitors, and is known to tote a shotgun to greet those ignoring his privacy!]
So back to research... On Train Orders,com, I found the following Thread from Apr. 2007 Linked @ https://www.trainorders.com/discussion/read.php?10,1395487
titled: 'Beyer-Garrett in Texas' {note: mispelling of 'Garratt'! }
Anyhow: back to business! This part is for Firelock76 and his posted comments {Thanks!] Posted by Flintlock76 on Saturday, June 13, 2020 7:50 PM
Wow!
Oh, wow!
Oh, wow, wow, wow!
6029's not a machine, it's a force of nature! So's 4014!
WAYNE [Flintlock76]: I THOUGHT YOU'D APPRECIATE THIS COMMENT, AS POSTED ON THE T/O SITE Quoted above.
Trainorders poster>author: FECSD40-2,
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