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Extreeem Steeam ! About Unconventionals - Part II

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Posted by Overmod on Tuesday, February 4, 2014 11:40 AM

Bumping this thread in case new member 'puffy' has an interest in its contents but hasn't seen it yet.

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Posted by Overmod on Saturday, July 13, 2013 10:21 AM

As a potentially amusing counterpoint to the Henschel motor locomotive, here is a Carleton Steins (of PRR V1/Triplex fame) patent.

Note the date this patent was filed... and the date it issued.  Then compare the Kirchhof patent for what would become Franklin type D , which is a logical system to use on such a locomotive.  (In fact, it may be possible that those little circles on the cylinder blocks are stand-ins for cambox covers, although nothing explicit is stated about the form of the motors in the patent itself.)

The type D system ought to eliminate most of the difficulty with physically coordinating cutoff control on separate motors, which required so much 'care' in the Henschel design as built and developed.  It also ought to facilitate rapid changes in direction with a simple control, one of the stated objectives in the Steins description.

Not the answer to diesels, either, but I'd surmise that neither Steins nor Kirchhof would have said so as late as the early Fifties.  And perhaps in some niches it might have been a reasonable alternative at that time.  A light version of this locomotive would be as flexible for various services as, for example, the 44-tonners PRR tried (largest that could be single-manned at that time), and certainly more capable...

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Posted by Juniatha on Saturday, July 6, 2013 11:23 PM

.. not too much - it provided an answer to a marginal question , an answer that involved quite an expense on engines if it had been series produced .

The best concept for steam motor type of locomotives has never been found .   The V2 engines frame mounted and driving axle directly via mechanical coupling allowing for suspension was a simple and logic concept , a parallel to contemporary electric loco development with E17 and E18 / E19 2-8-2 units .  Yet it was not an optimum .

I think the most interesting aspect of the unusual locomotive was that it actually ran in revenue service in as adverse conditions as WW-II and yet did achieve some success with nursing by Prof Roosen of Henschel and others .   It could have been further developed , no question , yet it provided no answer to diesels , for instance .

Regards

= J =

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Posted by NorthWest on Saturday, July 6, 2013 8:58 PM

What are your opinions on the DRG class 19.10? http://schneider-mayenfisch.com/drg_lokomotiven_19_1001.htm 

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Posted by CSSHEGEWISCH on Saturday, June 29, 2013 6:42 AM

Consider that every manned moon flight plus the shuttle flights began their trip with diesel power.  The crawler-transporters were powered by Alco 251 engines.

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Posted by Firelock76 on Friday, June 28, 2013 5:16 PM

CSSHEGEWISCH

Firelock76

Well now, extreme  steam fueled by LH and LOX!  Why hasn't THAT been tried yet?  Sounds intriguing.

Wayne

Only if you want to put a T1 on the moon!Laugh

Why not put a T1 on the moon?  Let's see a diesel beat THAT!

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Posted by CSSHEGEWISCH on Friday, June 28, 2013 7:08 AM

Firelock76

Well now, extreme  steam fueled by LH and LOX!  Why hasn't THAT been tried yet?  Sounds intriguing.

Wayne

Only if you want to put a T1 on the moon!Laugh

The daily commute is part of everyday life but I get two rides a day out of it. Paul
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Posted by Firelock76 on Thursday, June 27, 2013 6:18 PM

Hi Overmod!  Little Brother's not involved in aviation technology anymore, hasn't been for some time, although he still flys helos on occasion.  I doubt he'd know about PDE technology, but you never know.

Well now, extreme  steam fueled by LH and LOX!  Why hasn't THAT been tried yet?  Sounds intriguing.

Wayne

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Posted by Overmod on Wednesday, June 26, 2013 11:27 PM

Ask him about the timing, dispersion, and pulse modulation of the laser ignition in pulse detonation engines, and watch his eyes...  ;-}

Just practice the phrase if you don't understand why all the pieces are important.  This is one of the things that WOULD be classified if there were any point in using PDEs for high speed in transatmospheric vehicles... or certain other things related to the Northern Lights...

If you're interested in honing your skills, I can send you a review of PDE technology.  (Interesting by its absence is any mention of laser ignition, btw, which speaks to the flip side of classification, the delightful hiding-in-plain-sight that has worked in so many places over the years.)

The obligatory extreme-steam reference is that the replacement for the methane-fired PDEs is engines running LH and LOX.  And the ejected reaction mass is...   ???

!!!

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Posted by Firelock76 on Wednesday, June 26, 2013 4:55 PM

Well. the F-117 specs are declassified NOW  (maybe, maybe not, you REALLY think they've told us everything?)  but back THEN he had to keep his mouth shut.  We're talking 20 years ago.

However, I told him how I'd detect the aircaft's presense, and he gave me a knowing smile, showing me I'd got something right for once.

Don't ask me how or I'll have to kill YOU!

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Posted by Overmod on Wednesday, June 26, 2013 1:49 AM

Oh, for heaven's sake, all those aspects of the 117 have been effectively declassified for many years now.

It's also not that difficult to know how the various methods of RAM work, or how the airframe is laid up.  It just doesn't do any foreign power any good, because fabricating the microarrays alone is the national defense budget for most wannabees.  We just do what Reagan did: outspend 'em and watch them blow up trying to copy us.

Of course, the Australians had an OTH radar (that was essentially in the tin cans and string category as sophisticated EM equipment goes) which could detect the 117 ... well, over the horizon.  If you're familiar with weather radar, you will recognize how.

If you are wondering about the 'big engine' -- here ya go (just remember that almost anything else that used this engine had an afterburner section and was muuuuuuch bigger...).  If you still have residual curiosity, there are exploded view drawings and parts of the service manual on the Web too.

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Posted by Firelock76 on Tuesday, June 25, 2013 8:09 PM

He couldn't tell me any more than the "big engine"  remark.  If he did he'd have to kill me.

Wayne

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Posted by Overmod on Monday, June 24, 2013 8:13 PM

Firelock76
Ah yes, the F-117.  My brother did some engineering work on that one.  He calls it living proof  ANYTHING will fly if you put a big enough engine on it!

Hopeless Diamond airframes fly just fine.  They even have pretty good lift.

It's the fact that they're unstable as hell that makes them so much fun -- I bet your brother would be more likely to say ANYTHING will fly if you put a good enough six-axis control system on it... even something with all the glide of a set of car keys...

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Posted by Firelock76 on Monday, June 24, 2013 5:25 PM

Ah yes, the F-117.  My brother did some engineering work on that one.  He calls it living proof  ANYTHING will fly if you put a big enough engine on it!

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Posted by Overmod on Monday, June 24, 2013 2:43 AM

There are "DB equivalents' on steam locomotives, including various types of counterpressure brake (for example, the LeChatelier 'water brake'.  These tend to be limited by the small number of active drive wheels.  One railroad that used these on large modern power was D&RGW -- see LeMassena's article in the May 1995 Trains Magazine, and some intelligent discussion here, from 2003 but still useful.

One issue with these kinds of brakes is that you have to get rid of the energy 'liberated' by the brakes in some way.  As you probably recognize, this is considerable (think about how much heat has to be dissipated by the grids and fans).  Some versions of counterpressure brake involve converting the cylinders into air compressors -- which is great until you start having to dissipate the heat generated there by the compression -- which easily gets you up to the carbonization point of your cylinder lubricant ... in a higher-oxygen environment ... within a short effective time.  Hence the use of the 'water' -- which flashes to steam, provides the counterpressure, and is then exhausted carrying away the brake heat which is taken up as latent heat of vaporization.  Naturally the source of the 'water' involved can be complicated (I thought) if you're dosing the tender water with treatment chemicals -- one of the great '40s operational enhancements -- but I am assured from a number of sources that the small amounts of hemical do little if any damage.

An issue here is that the braking effort isn't as continuous as with multipoleTMs as generators, and you will get driver tire wear similar to what's produced over time by microslipping and wear.  This is not necessarily at the same point as traction-related wear, though.

I have seen proposals to do some 'hybrid' energy storage by saving some of the compressed air in reservoirs, for example in enlarged brake reservoirs.  (You don't want to do this with the actual brake air, of course, for a number of reasons I won't tediously go into here.)  The catch is that the compression heat is still excessively retained in the cylinder, with the back pressure now developed in the reservoir retarding net airflow out of the cylinders (and hence enhancing the spot heating).  That should not stop you from at least looking into the economics of using it.  (I don't see it as being cost-justified, or guaranteed safe or reliable enough for long-term use, but don't ever let what I or anyone else say necessarily keep you from working the calculations through for yourself.)

The treadwear contribution of the independent brake can be addressed as I indicated elsewhere, by using lateral caliper brakes that do not act to heat the tire directly.  I am unaware of other methods that would work on modern standard-gauge reciprocating locomotives -- although you are welcome to think up and describe something!

I have no hesitation in saying that electric motors on some or evel all the unpowered axles on a reciprocating locomotive will be beneficial -- only that if you do it at full '40s-'50s cost, over a limited installed base, you will not receive positive net return on the investment.  The situation changes dramatically when you have large numbers of 'tms available ... but that presumes large numbers of something like diesel-electrics, and perhaps whole generations of diesels that have been depreciated or scrapped leaving their motors for spare parts.  That situation does exist for modern steam, and is one of the recognized advantages of an asynchronous compound (in which the exhaust steam from the piston engine is used to run a large turbogenerator/turboalternator with its current used, in part, to run traction motors for boosting.  One significant reason to put diesel MU controls on steam locomotives is that an engine crew can control trailing road slugs to produce relatively cheap dynamic, with the slugs having full alternative use with diesels so there is low opportunity cost and low overall risk in developing the approach.  I do not know a better way to implement DB than with electric motors operating as generators of some kind, connected to an appropriate load.

I trust you have gone over the advantages and disadvantages of Belpaire vs. other forms of firebox construction.  There is extensive discussion of this in the literature, including a couple of specific threads on the Yahoo group steam_tech (which you might want to join).  I suggest that the Lima 'double Belpaire' design (in which the combustion chamber is no longer circular, for one thing) be a design you consider if you are retaining stayed firebox and chamber construction.

The shaft is not going through the firebox or throat plate.  It would be arranged to go under the ashpan, with appropriate shrouds to prevent ash dumping, corrosion from drips or blowdown, etc.  Obviously you would not put any u-joints, splines, or unsealed bearings in that zone if you can help it.

Note that even a deep-firebox boiler with a trailing truck under it has enough 'shaft clearance' to permit the arrangement to work with corresponding permissible wheel size.  If you use higher drivers in the trucks, you will want a Challenger-style boiler (where part of the firebox overhangs the drivers) or one of the higher-pitched boiler mountings (as on a modern 4-6-0 or 2-8-8-2). 

You might be tempted to run the shaft on one side of the firebox or the other, or to offset the boiler a la shay to make room for the shaft on one side.  I do not think I would recommend this, but if you can make the weight balance and not put too much angularity and intermediate gearing in the driveline, it is at least an option.  Depth is far more important than width in determining the efficiency of radiant uptake (see David Wardale's discussion of this in the British '5AT' project discussions) so having a deep, narrower firebox is not a Bad Thing.

Be sure if you are using shafts to multiple 'tender' trucks that you remember the culmulative load on the engine and 'first-in-line' gearbox bearings.  It's possible that you might want to use a transfer-case-like arrangement (where the engine shaft goes to a transverse gearbox and the output drives symmetrical' shafts forward and backward at roughly equal length to the axle drives).  Doing this also would facilitate using 'hybrod' style electric motor/generators somewhere between the engine's crankshaft and this transfer box, with two obvious locationg being on the back of the engine crankcase structure and bolted to or integrated with the transfer box's structure.   (That would also give you some of the 'third-rail' capability you were discussing -- look at the arrangements used on some of the '50s lightweight trains with diesel-hydraulic propulsion that had to use third-rail trackage into terminals.  (And at the ways those things could produce operational disasters -- 'fifteen more minutes and I would have been a hero' being one phrase you might want to look for...  ;-} )

There is plenty more you could add to the steam discussion; it just might not be as 'sexy' as the Big Ideas.  For a start, I suggest you look at ways to increase effective radiant uptake in the relevant section(s) of the boiler without causing 'quench' of the effective oxidation (combustion) reactions on the relatively cold inner surfaces in a regular firebox.  Or how you shape the combustion space and primary/secondary airflow for best effectiveness.  Bet you haven't studied the GPCS system in practice, or how it might be either stabilized or run with nonlinear control the way the F-117 has to be flown...

... and that's just the start of how you might look at things in steam....

RME

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Posted by NorthWest on Sunday, June 23, 2013 10:40 PM

Thanks...

Is there an easy way to eliminate the tread wear issues that dynamic brakes solve?

Putting electric motors on this would be an issue, both cost and maintenance wise. Any ideas?

Also, how to mitigate drive shaft and cylinder intrusion into the firebox, beside going with a Belpaire?

Beyond that, I'm unsure of anything else I can add to the steam discussion! Sad

 

 

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Posted by Overmod on Sunday, June 23, 2013 10:22 PM

Yes, the cylinder size is related to the boiler size.  Use the formulae in Ralph Johnson's book to get an idea of how.  Remember that the boiler can be very large, just as in the V1, to get the system to work; about the only thing you can't do is run the shaft through a firebox.

It's probably not as 'good' a solution to the starting problem as something like a Paget or Besler locomotive, where you have a very large number of little 'power pulses' per driver revolution.  There is no doubt that you have better effective TE per ton, and normally lower slip propensity ceteris paribus, with any of the geared locomotive designs; you also have much lower propensity to sustain a slip as the engines overspeed faster for a given throttle and reverser setting...

One place the design would have been extremely valuable is steam switching service.  That was the specific way the American locomotive was built, but it was a practical shortline engine too.  It was supposed to use submerged-flame combustors to get very high firing efficiency. 

As I have said elsewhere, I like this idea for geared drive rather than the multiple-engine-Sentinel approach. 

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Posted by NorthWest on Sunday, June 23, 2013 8:38 PM

Ah, I see, the name is the "Hyper-Heisler"

The question is, would this have been developed or used?

One question- would the cylinders affect the size of the boiler?

Thanks!

Edit- could this be a solution to the starting TE problem?

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Posted by Overmod on Sunday, June 23, 2013 8:05 PM

Throw Shays away -- they weren't and never would be high-speed locomotives.  And they only work on one side -- sketch the geometry on curves if you have any question about that.

Heisler is your principle.  (I would connect the truck wheels with intermediate gearing rather than with rods, because you'll have some of the rod-fracturing problems that rod-drive electrics did, due to the characteristics of and inertia in the drive train).  There is no particular reason why this would have to be a low-speed design -- in fact, there is very little reason why it couldn't be provided with some sort of change-speed transmission and be used at quite high speed indeed.

A Heisler engine at this scale would be essentially a 90-degree angle V4 to V8 cradled under the boiler, with the cylinder heads neatly exposable for maintenance, nice short steam and exhaust passages, and whatever crankcase arrangement you want -- cast ,or open with seal plating.  Cardan shaft drive with Nice Big Universals -- they're doubled for constant-velocity, and you can theoretically use big Rzeppa joints although their use in the '40s might not have been cost-justified!

I like the quills as final drive on the higher-speed version of this locomotive.  The unsprung mass however doesn't get much worse than it is on an RDC, and of course there is no direct augment in the suspension.  So you might get away with little more than the arrangement you see in a typical semi tractor rear, beefed up to take the shock loads, etc. in effective service.  Drive is slightly angled in plan to a pinion on one side, with the countershaft arrangement conjugating the truck wheels running on the other side (so the gears work to turn all the wheels in the same direction).  There are some pictures on geared-locomotive sites that show this arrangement with open gears -- fine for logging maintenance, but not imho desirable for long life or high speed -- and that will give you an immediate view of how the gearing is arranged.  Shafts between trucks are handled with splines and floating U-joints, and center bearings in the shafts where desired.

It might be interesting, as you indicate, to rig up a Heisler engine as a booster on something like a Garratt.  There is plenty of room below the boiler, the shafts go direct to the inside engine trucks, and the swing of the articulation to those trucks on a mainline-size locomotive should not be excessive.

The problem with vertical-engine boosters on the tender is that they'll take away too much space for both coal and water.  You want to minimize the tender tare weight as much as possible in the first place -- and driving the tender wheels has the same general problem as a conventional Garratt in that the FA goes down as the fuel and/or water is used.  This before you start figuring out where the steam and exhaust pipes to the motors have to run...

It might interest you to know that there were at least two advanced Heisler proposals I'm aware of (one in the United States and one in South Africa) and I believe Ted Pritchard in Australia had this layout prioritized for his 'railroad' locomotive plan, as it immediately fit his chosen engine configuration.

RME

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Posted by NorthWest on Sunday, June 23, 2013 3:25 PM

Okay- next thought.

What about expanding on the Shay principal?

Have 6 large cylinders on the tender, 3 on each side, powered by a full size boiler on the locomotive. Power 4 3-axle trucks (2 on the locomotive, 2 on the tender) by quill drives on both sides of the engine. This engine would likely be a slow speed locomotive, as Shays were, if there was no other gearing between the pistons and the drive shaft, to keep piston speeds reasonable. Best for helper service, with high TE?  

Thoughts?

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Posted by Overmod on Saturday, June 22, 2013 11:46 AM

This is exactly the place for this kind of discussion -- and if you open the old thread, readers get the older context too, instead of having to hunt for it or, more likely, trying to repeat it.

First: this is a better idea than you think -- in my opinion it would have been the salvation of the big RENFE 4-8-4s.  Take the idea to a logical conclusion: the part of the tender connected to the engine is almost all fuel, like a more extreme version of a PT, with most of the water in a double-ended A-tank.  When the locomotive is to be turned or hostled, the A-tank is disconnected -- this takes care of much of the turntable-length issue, and roundhouse stall length.  More than one A-tank becomes easy for extended running.

Second: for a general comparison of battery technology, you might look at the 'tripower' locomotives of the 1920s.  The capacity problem is not as terrible as it may appear at first glance if the system is primarily used for boosting, but I think you are proposing to use the system for continuous boost when needed as well as regenerative braking.  The danger in this is that railroads will consider the additional power 'normal' in making up trainlengths to make full use of their investment -- which will make reliability of the system more essential, and I suspect reliability of '40s TMs connected to large (recycled WWII submarine?) batteries might be less than stellar.  Don't forget that these batteries will require water and periodic hydrometer testing, will be venting a considerable amount of gas with estremely wide explosion limit in air (see useful table here) and acid leaks are going to pose a maintenance issue you'd need to be aware of.  You will also need to cool it during periods of high draw, perhaps actively with heat exchangers in the electrolyte space. The current draw inder load, and the amount of current to be 'sunk' in regeneration, are out of proportion to the levels seen in automotive practice; you MUST make the actual calculations to see what your peak currents can be.

Now that we are over here in this thread, we can relax some of the '40s assumptions.  Better battery chemistry is a 'plus' here (although you still get relatively lousy 'bang for the buck' out of it) and some of the charging issues are potentially helped with OTS equipment from hybrid vehicles that can be adapted to some of the specific issues, particularly the charge rate control during high-rate regenerative braking.  Both the TMs and inverter systems for AC drives can be made relatively water and crap proof, and the system can be modulated to produce effective torque and effective braking contribution right down to zero speed.  At even more cost.

I would be tempted to design this thing differently -- perhaps in the following general way:

Build the A-tank units as if they were road slugs -- control cab, etc. -- and make a substantial percentage of their 'adhesive weight' water mass.  You will baffle it well, of course, and carry it as low as possible to keep the SDP40F problems from recurring (!!)

Use the motors extensively for dynamic braking rather than boosting.  (You will rapidly run into the terrible consequences of reliance on DB if you aren't careful -- see the recent incidents on Seventeen Mile Grade for a good discussion why).  Instead of batteries, consider the use of short sections of cat or third rail only in locations where boosting will be required -- or regenerated power can be recovered practically. 

You might have some fun by adopting some of the things that were proposed for the GE "MATEs" (the original road, as opposed to yard/hump, slugs).  One of these was crew dormitory space, like a more sensible version of the 'corridor tender' idea used in the UK.  Would need some careful union approvals that would probably not be forthcoming in the '40s or '50s -- and might be of decidedly little usefulness in many contexts -- but might be a better solution than tender 'doghouses'.

Big issue is getting DC traction motors to live under water tanks.  I notice you chose oil fuel, perhaps after having read about the coal-dust issue on the C&O turbines.  TM cooling is going to be a critical issue (remember that this turned out to be a critical issue on the Baldwin Centipedes)

Things that are lost with longer tender arrangements;

Some weight and train-factor characteristics (more non-revenue weight)

Siding restrictions on train length (by however many cars now won't fit)

Engine use restrictions (when there is an insufficient number of tender units for any reason) or the same sort of problem you see with earlier 'married' locomotives assembled out of dedicated units (itself usually a management 'dodge' to get a multiunit locomotive approved by the union as a single engine).  If one bad bearing or seized TM takes the whole tender out of service, or holds up the whole locomotive on the road or in the shop -- money will be drooling between your fingers.

I do recommend that you find references on Russell Brown's 'asynchronous compound' idea (it was previously the 'Paragon locomotive' in a less-developed format) when looking at ways to power this system.  By the time you get exhaust off a tender booster, you have very little energy to run a practical traction generator, let alone something that will do much more than excite the fields on four trucks' worth of 746s or whatever.  Even if you had the mass flow at low pressure, you'd need a plenum alone close to AAR plate C clearances...and volumetric efficiency in your valves, turbine throttles, or whatever to match.

I have missed some points, so please remind me what they are.

RME

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Posted by NorthWest on Saturday, June 22, 2013 11:40 AM

Once underway, the traction motors would cut out. They are there to combat a couple problems with steam: starting TE,  and tread wear with no dynamic/regenerative brakes. While a locomotive is idle, steam that would otherwise be wasted could be used to charge the batteries, and regenerative braking would be used as well. Sort of on the road slug principal, but with batteries.

But, some steam would need to be diverted in order to always power the motors in order to eliminate extra resistance underway.

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Posted by CSSHEGEWISCH on Saturday, June 22, 2013 6:48 AM

You failed to mention a power source for the traction motors on the tender beyond third-rail shoes.  You would still need a sizable main generator/alternator (linked to a steam turbine?) to supply enough electricity for these motors to be useful.

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Posted by NorthWest on Friday, June 21, 2013 10:14 PM

Hello,

I'm reluctant to reopen an old thread, but I don't think this would fit in the other thread...

Okay- my Extreeem Steeam! Locomotive:

Everything forward of the tender stays the same, except for the rear truck. This locomotive would have two tenders. The first would be half oil, half water. The second would be half water, the second half batteries. The rear truck of the locomotive and the four tender trucks would have traction motors.

Advantages-

-Regenerative braking would provide power for the motors to provide TE for train starting, and ease wheel wear. They would cut out at a set speed. Dynamic brakes could be used once  batteries filled.

-Steam that would be used in the rear truck booster could be converted to electricity as well.

-Third rail shoes could help in cities, powering the locomotives, and avoiding anti-smoke laws.

-Greater range by more water capacity.

-Things I'm missing...

Disadvantages-

-Maintenance

-Greater length that would make roundhouses no longer workable.

-Greater weight to haul around.

-Probably wouldn't work with 40s battery technology.

-Things I'm missing...

So, is my mashing of steam and electric practical, or is there a huge problem(s) I'm missing?

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Posted by carnej1 on Thursday, January 17, 2013 11:14 AM

Overmod

Just for fun, and to illustrate some of what's available 'out there' -- here's a link to some reference material for the Comsol multiphysics environment:

http://www.comsol.com/offers/conference2012papers/?utm_source=Desktop+Engineering&utm_campaign=us_de_jan13&utm_medium=Demail&utm_content=1

 

Enjoy!

I made the link live for you (all you have to do is hit ENTER after you paste it).

"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock

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Posted by Overmod on Thursday, January 17, 2013 2:13 AM

Just for fun, and to illustrate some of what's available 'out there' -- here's a link to some reference material for the Comsol multiphysics environment:

http://www.comsol.com/offers/conference2012papers/?utm_source=Desktop+Engineering&utm_campaign=us_de_jan13&utm_medium=Demail&utm_content=1

Enjoy!

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Posted by Overmod on Wednesday, January 16, 2013 9:37 PM

 Before going down any Zoo gauge or amusement park route a possibly more enlightening, or educational option would be to build a highly accurate 3D virtual simulation of the locomotive in a computer.   With CAD-CAM [computer aided design & computer aided manufacturing], artificial intelligence and physics simulation software it would be possible to do a long of interesting stuff...

Efforts to do exactly this, in more than one suite of 3D CAD package, are happening.  This is generally more 'telling' than building a model, especially when considering CFD of the actual boiler -- most scale models have either simplified or different methods of boiler construction, combustion, etc.

Besides just running the model in an off-the-shelf train simulation package...

This is a different use of physics modeling than we'd want to use for design; most of the train-simulator software I know about requires that you know the working parameters, and develop the model from them, rather than going the other way.  You could use a kind of analogue to Newton's Method (or, moderately more 'precisely', numerical solutions to differential-equation-described complex situations ;-}) but there would be no guarantee of optimizing all the variables without a GREAT deal of comparison.  You would need to confirm that good data had been used to generate the actual models, too.

...you could also do finite analysis of all the static & dynamic masses in the locomotive, analysis of performance or thermodynamic &c.  Obviously we are not talking peanuts here...

Actually, the cost of implementing the solution is comparatively little, even including the training time and materials to learn the software effectively.  Note for example that AutoCAD now offers a very large number of its solutions, particularly including Inventor, "free" if you register appropriately.  You might not build detailed presentations with these... or use them for commercial purposes... but for the situations we're considering they are perfectly workable.  Just spend a few moments on eBay looking at used quad-core and eight-core processors to get an idea how cheaply the software can be run.

Needless to say, there should be extensive modeling in the computer before any actual construction work is undertaken.  That's true even if there aren't good deterministic models for some of the physics involved... at the very least, you're providing the engineering equivalent of due diligence.  (As a non-snide aside, the issue with high-speed slipping on duplex locomotives can be easily diagnosed with the 'right' model and physical suspension modeling -- and the various approaches to address the problem modeled, with stresses, and compared...)

(Maybe the virtual simulation could go some-way to answering the question the ATSF 3463 rebuild intended to explore.)

Consider very extensive modeling in CAD, and subsequent physical modeling in the computer, prolegomena to ANY actual development work, to say nothing of physical modifications to the locomotive should that begin...  <VBG>

RME

  • Member since
    December 2012
  • 20 posts
Posted by W.Shawn Gray on Wednesday, January 16, 2013 4:12 PM

G'day Juniatha, Paul et al,

Paul Milenkovic

Juniatha

You know , at that time I was not all too much concerned about how such an assembly could be put together in actual construction practice and what it would mean to extract one unit for an overhaul in case of wear or breakage .   The effects of time did not loom too large in my thoughts back then - yet it was not without charme and I think it wasn't a bad idea in principle - although it clearly would have demanded more in-depth attention to details , mostly about manufacturing , design and shaping of parts and ease of mounting / dismantling .

You or some others could always build it in "zoo gauge" (12" narrow gauge or whatever is popular for amusement parks and zoos featuring steam railroad lines traversing the ground).

<SNIP>

Paul Milenkovic

. . .  there are people who would have the money, skills, and opportunity to build Juniatha's Triplex Dream Locomotive (Traum Lokomotiv?).

Before going down any Zoo gauge or amusement park route a possibly more enlightening, or educational option would be to build a highly accurate 3D virtual simulation of the locomotive in a computer.   With CAD-CAM [computer aided design & computer aided manufacturing], artificial intelligence and physics simulation software it would be possible to do a long of interesting stuff.  Besides just running the model in an off the self train-sim package you could also do finite analysis of all the static & dynamic masses in the locomotive, analysis of performance or thermodynamic &c.  Obviously we are not talking peanuts here, but could be the next best thing to full-scale masterpiece of railway muscle.  

(Maybe the virtual simulation could go some-way to answering the question the ATSF 3463 rebuild intended to explore.)

W.Shawn

  • Member since
    December 2012
  • 20 posts
Posted by W.Shawn Gray on Wednesday, January 16, 2013 3:45 PM

G'day Juniatha, Crandell et al,

Juniatha

Hi Crandell

At this point I have to admit , in my 'walk on the wild side' type of private (pre-)engineering me too I had put up a concept of a Triplex , and just because of this very point - supplies vanishing & and tender adhesion mass alleviating - I had carried it just one step further , figuring if you can have two axles coupled in front of the main driver you could as well have the same on the back side of it - makes for a 10 coupled unit . 

You'd think I configured it to be a 2-8-8+10-2 ?  

Naw-naw-naw , sir - not with my way of thinking !   Ten coupled once introduced , I immediately thought "Why not have it on all the three engine units ?"   Mind my previous mentioning preference for identical sets throughout . So I ended up with a 2-10-10+10-2 - all simple expansion .   Sure enough there was that vanishing adhesion mass problem again .  

<SNIP>

Juniatha

Maybe I'll put up that old side view picture of back then , if you'd care to see it ?

Regards

Juniatha

Well this guy in Auz for one would love to see that picture.

Thanks,   W.Shawn

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