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triplex

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Posted by MStLfan on Friday, December 21, 2007 4:13 PM
 dredmann wrote:

With our supersize-me culture, pretty soon the only drink sizes will be 500 ml, 1 l, 2 l, and 3 l.

You already have 3 l bottles!?!?Wow!! [wow]

greetings,

Marc Immeker

For whom the Bell Tolls John Donne From Devotions upon Emergent Occasions (1623), XVII: Nunc Lento Sonitu Dicunt, Morieris - PERCHANCE he for whom this bell tolls may be so ill, as that he knows not it tolls for him; and perchance I may think myself so much better than I am, as that they who are about me, and see my state, may have caused it to toll for me, and I know not that.
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Posted by dredmann on Friday, November 23, 2007 11:25 PM

I have been described as a reactionary and a contrarian, and I have no use for Diet Coke, decaffeinated coffee, or light beer. I believe that the U.S. is the last superpower, and should not be afraid to behave accordingly when necessary. But I have to say, metric is so much easier--indeed, so manifestly superior in so many ways--that our failure to embrace it as quickly as we can do so practicably has been monument to our national stubbornness. I think in the long run it will cost us.

As far as women stopping the metric system cold, well, the food arena is arguably where metric has received its greatest acceptance. With our supersize-me culture, pretty soon the only drink sizes will be 500 ml, 1 l, 2 l, and 3 l.

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Posted by Virginian on Thursday, November 22, 2007 8:46 AM

All true, but thanks to the ladies we at least have dual language now.  Soft drinks require no mixing.  Look on Bisquick - all cups and ounces... YES !!

One thing about American business, they would make shells for the enemy as well as the allies if they could manage it, in fact I think they have.

Actually, I think it is worrying about how it will play in the press/media, particularly the third world media, that hold everything back.

Now all they have to do is figure out how human life can exist without emitting CO2.  The greenies'd just as soon we were all dead, but unfortunately dead people do not donate to 'causes'.

What could have happened.... did.
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Posted by tomikawaTT on Wednesday, November 21, 2007 10:17 PM
 Virginian wrote:

SI units have no place in steam locomotive discussions, because the noble steamers were long gone before the stupid metric system began it's French/Euro inspired invasion into the U.S.  Thank God the ultimate power in the U.S., the women, stopped it cold, when the litre tried to crawl into the American kitchen.

American manufacturers started using the metric system, and producing metric parts, before the USRA designed the first 'mass market' steam locos.  The parts were orders from France - for 75mm gun barrels and shells, among other things.  Seems that in 1916 the French were too busy using them to make them.

As for the liter invading U.S. kitchens, have you bought any soft drinks lately?

With horsepower and caffienated coffee, the U.S. put a man on the moon.  Now it's a huge contest to get off the launch pad alive.

The real problem is getting the environmental impact statement past the Federal and State pencil pilots and the lawsuits put up by someone in Brazil who might actually suffer damage if the whole rig goes wildly off course and crashes in his yard.  (Farfetched?  How about the Russian 'psychic' who sued NASA for spoiling her horoscope by crashing the Deep Impact probe into her favorite comet?)

Furlong grains per fortnight instead of horsepower, anyone?  I aced a thermo assignment with that one, years ago.

Bob Heinlein claimed that he once won a debate (at Annapolis, no less) by quoting something from the British Colonial Trade Board.  The opposing team couldn't refute it - mainly because there never was any such British governmental organization!

Chuck

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Posted by Virginian on Wednesday, November 21, 2007 1:09 PM

SI units have no place in steam locomotive discussions, because the noble steamers were long gone before the stupid metric system began it's French/Euro inspired invasion into the U.S.  Thank God the ultimate power in the U.S., the women, stopped it cold, when the litre tried to crawl into the American kitchen.

With horsepower and caffienated coffee, the U.S. put a man on the moon.  Now it's a huge contest to get off the launch pad alive.

Furlong grains per fortnight instead of horsepower, anyone?  I aced a thermo assignment with that one, years ago.

What could have happened.... did.
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Posted by oscaletrains on Monday, November 12, 2007 10:58 AM
Confused [%-)]Dead [xx(] my brain hurts im gonna go lay down.
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Posted by dredmann on Monday, November 12, 2007 12:13 AM

speed (which is an expression of magnitude alone)

I don't think I would put it that way here, even in the more technical sense, because to do so is to create confusion in the likely audience, instead of understanding. Speed does not tell you direction, true, but it is not unitless. The speed isn't 5; it's 5 m/s. The velocity might be, say, 5 m/s composed on +3 m/s in the "x" (to use descriptors most people understand) direction, -4 ft/s in the "y" direction, and 0 m/s in the "z" direction. So if the veloity is (+3 m/s, -4 m/s, 0 m/s), you want to say the magnitude of this is a speed of 5 m/s. But once you have the appropriate unit (here, speed in m/s), you can churn through the math; it's just that, in doing so, you're assuing that it's all in the same direction. Here's that's a reasonable assumption.

I would agree that in the more technical sense, the direction can be important. But here I think it is a needless complication. For the practical purposes of the question here, the sum of the vectors and the "magnitude" can be taken as the same. Again, are we trying to help people understand, in real-world terms, what tractive effort and drawbar horsepower mean? Or are we going to present the physics in a way that will scare off most people? I submit that there's no good reason to do the latter.

More technically-inclined railfans understand that grades, curves, etc. increase the load on locomotives, and some of 'em can do the math for the rules of thumb. But I think even that is beyond the real scope of the question.

Last but not least, I don't understand your comment about torque. Force times distance, N x m. What is your concern / point?

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Posted by selector on Friday, November 9, 2007 10:07 PM
For the parameters initially stated, and with an assumption that the five miles worth of cars are not light but are loaded, the limiting factor might be the couplers themselves, and not horsepower, boiler or firebox capacities, etc.  Of course, tractive effort would be involved for a coupler to fail.
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Posted by JT22CW on Friday, November 9, 2007 12:38 PM

 dredmann wrote:
JT22CW, on the physics, you are partially wrong, and I am totally right. Power equals both force times speed and work divided by time. Try the units (here in metric for simplicity) and you will see. Power = force (kg) x speed (m/s) so power can be expressed in kg x m / s. Now power also = work / time, where work = force x distance, so power = force (kg) x distance (m) / time (s), so again power can be expressed in kg x m / s. As one of my professors used to say in one of the mid-level mechanical engineering classes, "The units will bail you out." (As long as you can avoid some of the quirks like the English use of ft-lbs for kinetic energy and lb-ft for torque!)
If "the units" could "bail you out", then torque would be expressed in joules in the SI system and not Newton-meters.

I'll be happy to stand corrected on the point that watts and horsepower come from force times velocity, but not when force is multiplied by speed (which is an expression of magnitude alone).  You need the sum of vectors to come up with the proper power figure, not just one vector.

Here we are basically assuming that the locomotive is pulling a train in a more-or-less straight line, in one direction. The need for vector math assume that the forces and movements have something other than an essentially one-dimensional nature. For this discussion, one dimension suffices nicely
Only for average calculations.  Any disparities between wheel HP and drawbar HP show the differences in the vectors.  Your motion may be in the i unit-vector direction, but your vectors might be projections (necessitating dot-product calculations to get the resultant vector, between the direction vector and the i + j force vectors; and these vectors are always present on grades).  And of course, if you have curves in the track, you end up with the i + j + k three-dimensional vector situation…

Of course, like already noted, the end result is that the triplex's horsepower was quite low. 

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Posted by oscaletrains on Friday, November 9, 2007 10:34 AM
form room and math class all in one sitting, altho i did kinda ask for it. Smile,Wink, & Grin [swg]
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Posted by dredmann on Friday, November 9, 2007 9:26 AM
[feeling somewhat sheepish]

Force of course is in Newtons, not kg. It makes no difference to the main issue, but that was sloppy on my part. If you don't use this stuff regularly, you get used to equating kg and lb, which is not really right; lb are force and kg are mass.
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Posted by dredmann on Thursday, November 8, 2007 3:37 PM

P.S.

If you want to hang your hat on the technical difference between speed being different from velocity, you will have to confine your discussion to engineers and physicts who enjoy keeping things overly technical. To most of the world, and for most purposes, they are the same. Here we are basically assuming that the locomotive is pulling a train in a more-or-less straight line, in one direction. The need for vector math assume that the forces and movements have something other than an essentially one-dimensional nature. For this discussion, one dimension suffices nicely.

 

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Posted by dredmann on Thursday, November 8, 2007 3:34 PM

I wrote: "power is force times speed"

To which JT22CW replied: "Actually, power is work divided by time. . . . You can't multiply force times speed because speed is merely the magnitude of a velocity, and velocities do not have forces acting upon them; further, the speed does not indicate a direction."

JT22CW, on the physics, you are partially wrong, and I am totally right. Power equals both force times speed and work divided by time. Try the units (here in metric for simplicity) and you will see. Power = force (kg) x speed (m/s) so power can be expressed in kg x m / s. Now power also = work / time, where work = force x distance, so power = force (kg) x distance (m) / time (s), so again power can be expressed in kg x m / s. As one of my professors used to say in one of the mid-level mechanical engineering classes, "The units will bail you out." (As long as you can avoid some of the quirks like the English use of ft-lbs for kinetic energy and lb-ft for torque!)

So as you will see, force x speed and work / time give you the same units, and indeed BOTH tell you the power.

On that basis you will see that drawbar or coupler force and speed play an equal role in deriving power, and a locomotive such as a triplex that can only put a lot of force (say, the mentioned 199,000 lb) at a very low speed (5 mph) may well have a lower maximum power output (especially on a sustained basis) than a locomotive that pulls with much mess force (say, 40,000 lb) but can do so at 60 mph. The latter will be capable of producing about 2.5 times as much power as the former.

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Posted by JT22CW on Wednesday, November 7, 2007 11:57 AM

 dredmann wrote:
power is force times speed
Actually, power is work divided by time.  (Just to recap physics quantities, force is mass times acceleration, work is force times distance, momentum is mass times velocity.)  You can't multiply force times speed because speed is merely the magnitude of a velocity, and velocities do not have forces acting upon them; further, the speed does not indicate a direction.

Since power = work ÷ time, then indeed the triplexes had very low HP, wheel and drawbar. 

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Posted by oscaletrains on Wednesday, November 7, 2007 7:13 AM
though impractical, it would be cool Smile [:)]
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Posted by dredmann on Monday, November 5, 2007 1:21 PM
Strictly speaking, I doubt such a locomotive would be very powerful. Even assuming you could generate a lot of force at the coupler (or drawbar), power is force times speed. As others have pointed out, the triplexes failed in part because their boilers could not generate the steam to power the three sets of cylinders, except at very low speeds.

As for the five mile train, well, I think someone would quickly shoot those in charge, for blocking crossings for way too long. A five mile train going five miles an hour will take an hour to clear the crossing.

If Bill Gates wants to get a monster rolling again, there exist 8 Big Boys, an N&W Y6a, etc.
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Posted by JT22CW on Saturday, November 3, 2007 2:58 PM

we all know about the famous TRIPLEX the bigest steam locomotive ever bulit
Certainly wasn't the biggest in any dimension.  Their only superlatives were the number of driving wheels (24 altogether) and low-speed tractive effort (the VGN's simple-expansion version could reportedly get 199,560 lbs at 5 mph); and oh yeah, how much steam they consumed (there was also the "variable-adhesion problem" as the drivers lost their grip with the steam, water and coal being used up).  The Erie ended up using theirs as pushers.

Also, "five-mile long train" is a bit hollow unless you are specifying the weight it's carrying. 

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Posted by Paul Milenkovic on Friday, November 2, 2007 9:19 PM

Based on Parker Lamb's Perfecting the American Steam Locomotive and some more colorful accounts from Robert L Massena some years ago in Trains, the Erie (and also Virginian) Triplex locomotives were not only failures but abject failures in that they were built with ridiculously small grates and low boiler capacity in relation to the number of cylinders.  They just couldn't keep up steam pressure at anything faster than a crawl.

If one were to build a Triplex, I suppose it would have to be a new design more along Super Power concepts of providing a big grate, firebox, and high capacity boiler.  Something like the Allegheny 2-6-6-6 had plenty of boiler capacity and not enough drivers for the drag service it was pressed into.  Perhaps you could put a booster engine on the last axle of the 3-axle trailing truck and run the other two axles with side rods in the fashion of some tender boosters, and you would have a fully-articulated 2-6-6-6 with 9 axles powered at slow speeds.

If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?

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Posted by cprted on Friday, November 2, 2007 6:30 PM
Actually, Bill Gates is a railfan. But from what I understand he is more into modern railroading. Besides, his charitable money is tied up feeding half of Africa or something.
The grey box represents what the world would look like without the arts. Don't Torch The Arts--Culture Matters http://www.allianceforarts.com/
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Posted by tomikawaTT on Friday, November 2, 2007 4:58 PM

I don't doubt that if Bill Gates was a big railfan and didn't mind pouring the price of a B-2 down a rathole the Triplex could be reproduced in 1:1 scale.  I also don't doubt that a century of technological advancement would make it a far better locomotive than the original.

That said, it would be about equivalent to building a new battleship to the design of U.S.S. Nevada.  Sure, it can be done.  WHY would anyone bother?

Chuck

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triplex
Posted by oscaletrains on Friday, November 2, 2007 11:07 AM

we all know about the famous TRIPLEX the bigest steam locomotive ever bulit!

i have seen many live steam models of the triplex, but, if, we could find the orignal buliders plans , could it rise from the ashes and run again? if we were to bulid it today, we could pull that famous  5 mile train!  the question posed here is if it could be done, not how pratical it would be. but how exspencive would it be to bulid and, how powerfull compared to deisels would it be?

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