I saw the photo of the Erie Triplex in the February issue. The third set of pistons were mounted beneath the cab with rods connecting to drivers on the tender. I've never seen this type of a wheel arrangement on any other type of locomotive, was this a unique design or was it tried on other smaller locomotives as well? A Consolidation locomotive (for example) would have room for pistons under the cab. By powering the wheels under the tender you would have some of the advantages of an articulated locomotive but on a rigid, shorter, frame... a more powerful compact locomotive.
Virginian had Triplexes too, but they aren't significantly different from the Erie locomotive to 'count'.
Actually, though, what you have is a 'third engine' with cylinders and drivers in rigid alignment, with the cab and tender body happening to be located above it. It isn't so much that there is 'room for the pistons under the cab' as that you have three eight-drivered engines in a row (the forward one hinged to the middle a la Mallet, and the rear one articulated to the middle one) with a guiding truck at each end of the chassis.
There was some experimentation with just the kind of 'enhancement' you describe, as early as Archie Sturrock's steam tenders (described in Fryer's book on experimental British steam), with the most famous American examples probably being the 'tractor' or 'motor' tenders used on the Southern Railway (shown here, in Parker Lamb's book.
The more 'tried' version of this approach was the 'auxiliary locomotive' (in four-wheel and six-wheel versions) tried by Bethlehem et al. -- these had the not unimportant characteristic of fitting underneath a tender of normal capacity, not one with a high deck and limited water capacity. While a conventional engine wouldn't have the severe augment-balance issues the auxiliary locomotives did, they still represented 'too many legs and not enough steam' when tried in practical service.
Were a Consolidation chassis, or perhaps a Mastodon/12-wheeler chassis (to get a bit better weight-bearing capacity), built with a Really Big Boiler, or with all the thermodynamic improvements of the '20s-'50s, the idea might have worked a bit better. It could be argued that the D&H high-pressure experimentals could have been built with multiple engines, rather than multiple-expansion on a single low-drivered wheelbase, and then rebalanced in the late '30s following the general principles applied to T&P 610. This would have given an engine operationally similar to the D&H Challengers, at shorter length and probably lower weight; it's even possible that compounding would give the same sort of lower water rate observed on N&W, and give longer range even without a separate water A-tank.
But this is all a lot of additional complexity for not that much operational improvement, and I suspect that any experiment with radical pressure increases out of a riveted-construction boiler using even '30s metallurgy would Not Be A Happy Experience. (I still haven't gotten the truth out of how well the original NYC 4-8-4 ran (it's arguable how sensible it was to provide so large and prominent a steam gauge to display 850 psi to the hapless crew required to run the thing!) but I can't imagine it would have taken very long before something more or less Fury-like occurred... same with the last versions of the D&H high-pressure locomotives, even absent the fancy and flawed Schmidt-style arrangement...
There's a picture of a Southern engine with a 4-4-0 engine under the tender in the October 1917 issue of Popular Science, which is available on Google Books.
- Erik
Don'r forget Garetts!
There were thousands of Garratts built, with driving wheels under each tender and nothing under the boiler. Also consider three and four-truck Shays, Sturrock steam tenders and a host of other designs.
In addition to Shays, there were Heiselers and Climaxes with trucks under the tender.
One of the problems with putting power under the tender is that weight on divers changes considerably as fuel and water are consumed. Virginian's lone triplex was not particularly successful due to inadequate boiler capacity, but it also had a reputaion for being slippery on the back end. IT was ulimately rebuilt into an AF class 2-8-8-0, with a new boiler and cab used to build an essentialy new MD class 2-8-2., both of which were considered successful.
Thanks to all of you for the responses... more questions to follow!
Tank engines also have the disadvantage of varied weight and thus adhesion.
While I will concede that the weight of the tenders will vary as fuel and water are consumed, Wiener noted in "Articulated Locomotives" that the factor of adhesion for Garratts, Shays and other such articulated locomotives was calculated based on empty tenders and water tanks.
And the tender weight problem (if that was indeed a concern) could be resolved by keeping the tender near full or by enlarging the tender's capacity, or even by constructing the tender with a heavier frame.
UlrichAnd the tender weight problem (if that was indeed a concern) could be resolved by keeping the tender near full
This would restrict range, however, but probably isn't a problem for helper service.
One possibility is to use a "canteen" water car with a pump to keep the water tanks full longer, although the coal would still be consumed.
The front tender truck of some Indiana Harbor Belt 0-8-0 switchers had a steam booster built into them. The two sets of wheels were connected by siderods.I believe they were similar to the boosters some steam engines had in their rear trucks, like New York Central Hudsons had.
http://www.dhke.com/ihbarchive/101.html
wjstix The front tender truck of some Indiana Harbor Belt 0-8-0 switchers had a steam booster built into them. The two sets of wheels were connected by siderods.I believe they were similar to the boosters some steam engines had in their rear trucks, like New York Central Hudsons had. http://www.dhke.com/ihbarchive/101.html
The auxiliary locomotive was generally even more 'adaptable' than a typical booster (which normally acted on only one axle of a trailing truck, and used wheels of greater diameter than on typical tender or freight trucks). It would fit nicely under a conventionally-dimensioned tender and allow some proportion of the tender's mass to add to adhesive weight at starting and low speeds... usually more restricted speeds than an equivalent booster would be able to use.
For more on the difference between the Franklin and Bethlehem boosters, go here for some additional information.
The 'fastest' road locomotive I'm aware of that had these was a class of LV 4-8-4; my understanding was that they were often in the shop, and were replaced with more conventional trailing-truck boosters at a relatively early date. It's possible that these have falsely acquired a 'bad name' as track-wreckers, in the same way that the PRR T1 was wrongly supposed to be hopelessly slippery... but it does appear that almost everywhere the auxiliary locomotives were used, they were either removed or modified to remove the outside counterweights and rods.
There is a somewhat jaw-dropping pair of pictures in "Decade of the Trains - the 1940s" (pp.40-41) showing what a couple of the things in action looked like. There is also this rather wonderful video showing the procedure for running an auxiliary locomotive/tender booster (admittedly at model scale).
One of the four-wheel auxiliary locomotives survives on LS&I 35 at IRM. Here's a picture:
showPicture.aspx?id=75227
The surviving ex-Union 0-10-2 shows how an auxiliary locomotive could be modified to solve its evil effects on civil engineering, without the expense of a whole new high-capacity truck. (I cannot find a suitable Web-accessible illustration, to my horror, but they do exist...)
Apparently when LS&I 34 went to the Hocking Valley Scenic, it too still had its tender booster. Apparently the device was so unfortunate in their service that the shop people not only removed it, but scrapped it...
Nice to see the picture of the IHB U-4a, the "grandest 0-8-0 of all". David P. Morgan was right, the boiler would do justice to a heavy 2-8-2. I would opine that the auxiliary engine on the tender was used to make better use of the boiler's steam-making capabilities.
Isn't the C&O 614 equipped with a "booster" engine? The wheels under the tender can be steam driven? I seem to recall reading that Ross blew the gears off of it on a hard start, many years ago while he was doing his ACE trials. (American Coal Enterprises?)
SAR had one class of Bayer-Garratt which ran with an auxiliary water tender. The over-the-driver cisterns were kept full until the auxiliary tank was drained completely.
Chuck
Golddusty Isn't the C&O 614 equipped with a "booster" engine? The wheels under the tender can be steam driven? I seem to recall reading that Ross blew the gears off of it on a hard start, many years ago while he was doing his ACE trials. (American Coal Enterprises?)
This was the usual sort of (Franklin) trailing-truck booster. Wardale recounts the booster damage in the chapter on ACE in the Red Devil book.
uncle pete[UNION PACIFIC] tried "boosters" I. E. traction moters under the fuel tender on there big double engine diesels. I believe they were the ones from GE with the airplane engines . they were called big blows
No they didn't, the fuel tenders on the 8500hp GTELs did not have traction motors.
ML
rbandr uncle pete[UNION PACIFIC] tried "boosters" I. E. traction moters under the fuel tender on there big double engine diesels. I believe they were the ones from GE with the airplane engines . they were called big blows
You have to be more specific. Or provide some exact references.
The U50s (some of which rode on underpinnings from the earlier turbines), which are the GE "double-diesels" UP ran, did not have dedicated fuel tenders, nor were they set up to work as "slug mothers" with additional traction motors -- to my knowledge.
The "Big Blows" were the last generation of turbines, 8500 hp, and they did not have motors of any kind on their fuel tenders. Nor were the turbines "airplane engines" except in the sense -- and it's a stretch -- that you might have an airplane that needed an 8500+-shp turboshaft engine. (The Russians had something in that class... we chose not to.)
I am hoping Jerry Pier will contribute here; he is an expert on all the different kinds of UP power, specifically including the turbines, and if there were indeed some attempt to implement a MATE-like concept on a fuel tender, I expect he would know.
Overmod, I am with you, though my information concerning UP power came from what was published in Trains--and I do not recall seeing, in the past 62 years, anything like what was mentioned. I was a bit puzzled by the reference to "double engine diesels," especially to "the ones from GE with airplane engines." I always understood that the "Big Blows" were the turbine-powered engines--which did have a diesel engine for use at low speeds.
Perhaps Jerry Pier can enlighten us.
Johnny
My understanding was that the turbines used on the Big Blows were based on industrial turbines, though there was likely a lot of cross pollination between GE's aircraft engine business and their industrial turbine business.
One of the Trains Motive Power Survey's from the early 1960's mentioned that the UP was looking into putting traction motors under the fuel tenders. Don't think that project got anywhere past the research stage.
erikem My understanding was that the turbines used on the Big Blows were based on industrial turbines, though there was likely a lot of cross pollination between GE's aircraft engine business and their industrial turbine business. One of the Trains Motive Power Survey's from the early 1960's mentioned that the UP was looking into putting traction motors under the fuel tenders. Don't think that project got anywhere past the research stage. - Erik
Apparently there were a few references in TRAINS magazine back in 1962-63 claiming that UP did test traction motors on the fuel tender of at least one of the 8500 HP turbines (allegedly the same unit that supposedly was trialed with the turbine power ratings upped to the point that the traction HP rating increased to 10,000 HP, another disputed claim) but as far as I can tell nobody has ever been able to verify that and there is no photographic proof. The consensus among rail historians seems to be that the idea never "made it into iron" so to speak...
It's an interesting possibility, along with General Electric's supposed presentation (around the same time) to the UP on a next generation turbine electric design rated at 15,000 HP (with U50 style bolstered bb-bb trucks under both units of the locomotive, I imagine that the design may well have had a traction motor equipped fuel tender as well).
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
one test unit was built. my wifes uncle has been with ge 50 years. up tested but never ordered any. the problem was the same as any tender steam boosters. no fuel, no weight, no,traction. not cost effective.
rbandrone test unit was built. my wifes uncle has been with ge 50 years.
Have him contact Will Davis ASAP -- he is a precious natural resource regarding how the increased-power testing on the GTELs was conducted. There are particular ways to 'debrief' him and get at all the latent details of what he knows but will only remember when prompted correctly...
In my opinion, it would make sense to motor the fuel tender of an 'uprated' 8500 hp GTEL, if using '60s-era control gear. I'm guessing that the motors on the tender axles might have been lower-rated than the locomotive's principal traction motors, with the effective "FA" calculated at some minimum loading (as for Garratts). Can you confirm or disprove that?
it was at a family reunion and funeral for my ex-father-in-law. odds are not good to revisit with. he is in his 80's and not near me. his neice is now my ex-wife.
Convenient...
he was back and forth between his home in LA and Paola Kansas where he was a consultant inspecting parts 4 overseas nuclear components. when u grow up maybe u can get a big boy job as well mr smart ass!!!
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