I was laying awake the other night and thought "Is locomotive power to scale? Does a locomotive that has 4000 hp on a prototype have 45 hp?" Now I know that sounds dumb, because obviously it doesnt, but does it have the same tractive effort. Could two HO locomotives pull an HO mile long train? How close are locomotives to being able to pull models equivilant to what they can pull on the mainline?
The rights of neutrality will only be respected, when they are defended by an adequate power. A nation, despicable by its weakness, forfeits even the privilege of being neutral. -Alexander Hamilton
There is no direct relationship. Go to sleep.
Stay off the caffeine. Sorry, couldn't resist.
Whenever you read a review of a certain locomotive pulling a certain number of cars doesn't mean you should. If you model diesels, you should consist them together anyways. It will save the locos from excessive wear.
I will give you an example. I have an eight unit Amtrak Superliner train with a baggage car. One P42 loco can pull, but not far. I always use two and it works well.
There is a ratio that one loco should be able to pull 10 average sized freight cars. So if you have a thirty car train, you should pull it with 3 locos.
Finally, follow Mark's suggestion and go to sleep.
But seriously, hope this helps.
Will
Here's a little more on the same subject: Drawbar pull and tractive effort. The second post there just about sums it up.
Now you can go to sleep.
Wayne
HEY!!
Will you guys keep it down? I'm trying to SLEEP here!
Darrell, quiet...zzzzzzzzzzzz...for now
Dude, you're thinking too much. But then again I did the same thing. The MR 08/08 issue last year of "Three track plans for one sheet of plywood" was at the back of my mind. Well I pulled it out, read it over a bit, looked at the Indiana & Aurora, and started thinking too much. Now I have a plan on how to make MR's track oh so slightly better, which buildings I would use where, what trains to use....well it just got worse and worse. I went as far as planning out different consists, just what the RR would call these consists, and started giving them numbers. An ops session would consist of 4 standard trains, plus an extra. F3's, GP30's, RS-27's, SD7's or 9's, SW1200's....yeah I thought too much. And now I have to rework it. 1 engine for every 10 cars, so what now my 15 car "grain train" made up of PS 4427's should have an F3 A/B powering it? It doesn't seem prototypical to me. But it does give me an exscuse to go buy that powered F3 A/B unit set on sale for $45 at the LHS. If it would still be there. If not that F7A might still be there. For surely those SD7's will be there. Or that GP30, although if I got that one I wouldn't want to repaint it.
So how's your Indiana RR coming along sleepy head?
indiana rr I was laying awake the other night and thought "Is locomotive power to scale? Does a locomotive that has 4000 hp on a prototype have 45 hp?" Now I know that sounds dumb, because obviously it doesnt, but does it have the same tractive effort. Could two HO locomotives pull an HO mile long train? How close are locomotives to being able to pull models equivilant to what they can pull on the mainline?
Neither the tractive efforts nor the weights of the cars (loaded vs. unloaded) scale down.
So, no, there's no relationship.
Interesting nightmare. If you divide the weight of a standard diesel 410000 lbs by 87 you get 4712 lbs. I doubt if you have any HO models that weight over two tons??? Weight and capacity is not a single dimension. Most of the new diesels carry close to 5000 gal of fuel divided by 1/87 = 77 gal of fuel. Not likely in an HO model.
CZ
There's an argument that says you have to do the calculation in three dimensions...think of it this way, if you bought 87 HO 40' boxcars and put them in a real 40' boxcar, you'd have a LOT of room to spare.
If you take an engine weight of 410,000 lbs and divide by 658,503 (87 x 87 x 87), you get .62 lbs which is pretty close to an HO model loco's weight.
Anyway...re the original post, the answer from my experience is that no, model engines are not as powerful as the real ones, relatively speaking. A real engine type that could pull say 40 cars by itself normally will be doing good to pull half that amount in HO.
Scale weight is definitely defined in three dimensions, so that the weight in 1/1 scale is divided three times over by 87. That is, the height, length, and depth are all reduced to 1/87 scale.
Power is a function of work done per unit of time, so you might want to agree that time stays in 1/1 scale; a 1/87 minute or hour or day is the same length as a 1/1 minute or hour or day. Leaving time in 1/1 scale solves many problems, and you can then go ahead and calculate how long a train a locomotive can pull up such and such a grade, and at what speed.
You might run into some arguments or contradictions with the operations crew, who believe that a large railroad can fit in a small room. Those guys seem to be working in two scales; model scale of 1/87 (or 1/160), and operations scale which is controlled by a fast clock, and/or a belief that their railroad should be capable of accomplishing a "day's work" in a few hours of an evening of operating. The distance scale often translates into many miles being compressed into a few feet between stations or towns or yards, while the operating scale is keyed to how many minutes various switching moves might take. There is really no mathematical way of reconciling all these scales, which is why power cannot be readily scaled into operations on a model railroad. The more simple approach is to leave out the time element, and just use the timeless factor of "tractive effort", which tells us how many cars can be pulled up a specific grade, and doesn't bother with the time it takes to do so.
I remember years ago when I used to be heavily invovled with Live Steam.........
You just can not scale down PSI..... nor weight.......nor tractive effort...........nor an EMD 645-V16.......etc...etc....
So kindly go back to sleep and worry about real problems........such as... how many turnouts can I cram into my layout??........how many locos can I run on my layout????.......should I go with a 5 amp DCC system or a 1000 amp system???...................can I stuff 100 pounds of crap into a Dixie cup?
Dennis Blank Jr.
CEO,COO,CFO,CMO,Bossman,Slavedriver,Engineer,Trackforeman,Grunt. Birdsboro & Reading Railroad
You should be thinking of real life stuff. Example, If you choke a Smurf what color does it turn? If traffic lights are timed at 35 mph would doing 70 mph be better? If the horn blows and the carburetor sucks what does the driver do? Why do drive up ATMs have braille keys? How come the color Peach does not match the fruit?
I started with nothing and I still have most of it left!!!
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
dgwinupHEY!! Will you guys keep it down? I'm trying to SLEEP here! Darrell, quiet...zzzzzzzzzzzz...for now
I can't help but wonder if you were unimaginably stifled as a child, hence the phrase" Darrel quiet for now".
Although it is rather funny
You should lose sleep over model locos pulling. You should be wondering if you're going to do good at work. Will the car start? Why do banks leave their doors wide open when they chain the pens to the counters. Why do hot dogs come in packages of ten and buns only come in packages of eight. Why do many Americans leave their cars out side when they have a garage to park in? Oh wait, I can answer that one. It is so they can play with their trains.
Sorry, I just can't help my self.
I could not sleep either.
A HO scale mile is 60.6 feet long. Setup a layout and try it out and get back to us. Inquiring minds would like to know.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
wjstixIf you take an engine weight of 410,000 lbs and divide by 658,503 (87 x 87 x 87), you get .62 lbs which is pretty close to an HO model loco's weight.
Dr. Frankendiesel aka Scott Running BearSpace Mouse for president!15 year veteran fire fighterCollector of Apple //e'sRunning Bear EnterprisesHistory Channel Club life member.beatus homo qui invenit sapientiam
wholemanThere is a ratio that one loco should be able to pull 10 average sized freight cars. So if you have a thirty car train, you should pull it with 3 locos.
Where in the world did that idea come from? If that's true for models, ALL my locomotives are vastly overpowered! My MDC Harriman 2-8-0s can pull around 30 not-so-free-rolling cars, and the 4-6-0 does about 25 - I haven't found the limit yet (I don't have enough track) of my Bowser T1 4-4-4-4 (and my cars are also weighted to NMRA standards). And If it's referring to the prototype, the GP-38 that the UP has stationed at the Bonner Springs junction is also way overpowered, since it regularly pulls around 15-20 cars and is not working very hard at all.
And weight scales down in 3 dimensions, but not very accurately - a 140,000-lb 40' boxcar scales down to 3.4 ounces in HO, but I doubt that it also works for all scales. I haven't researched it very much, since I don't really give a hoot, but I also doubt if it would work on all motive power, either.
I agree - go to sleep.
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Gary M. Collins gmcrailgNOSPAM@gmail.com
===================================
"Common Sense, Ain't!" -- G. M. Collins
http://fhn.site90.net
Scaling down weight is accurate if (and only if) the model is built exactly like the prototype using the same materials. As others have stated, you have to divide the prototype weight by the scale factor to the 3rd power. This doesn't translate well to most model locomotives, since an HO scale locomotive is constructed nothing like the prototype. However, in my experience, it works out very good for estimating the finished weight of a live steam locomotive that is built faithful to the prototype, or for models of wood cars that are built with scale sized lumber board by board. Adding extra weights that the prototype doesn't have will certainly make the models weigh more than scale. Now, translating that into model HP, which one horsepower = 33,000 llbs lifted one foot in one minute is a whole 'nother matter. Not to mention that models tend to have proportionally more friction than their full size counterparts, further complicating model tractive effort calculations.
I'm going back to sleep, before my brain starts to hurt...
gmcrail wholemanThere is a ratio that one loco should be able to pull 10 average sized freight cars. So if you have a thirty car train, you should pull it with 3 locos. Where in the world did that idea come from? If that's true for models, ALL my locomotives are vastly overpowered! My MDC Harriman 2-8-0s can pull around 30 not-so-free-rolling cars, and the 4-6-0 does about 25 - I haven't found the limit yet (I don't have enough track) of my Bowser T1 4-4-4-4 (and my cars are also weighted to NMRA standards). And If it's referring to the prototype, the GP-38 that the UP has stationed at the Bonner Springs junction is also way overpowered, since it regularly pulls around 15-20 cars and is not working very hard at all. And weight scales down in 3 dimensions, but not very accurately - a 140,000-lb 40' boxcar scales down to 3.4 ounces in HO, but I doubt that it also works for all scales. I haven't researched it very much, since I don't really give a hoot, but I also doubt if it would work on all motive power, either. I agree - go to sleep.
I remember reading that somewhere in the past on these forums. The situation was that someone was having trouble with pulling cars. I guess I must of misquoted someone since I hadn't had good sleep the night before. I wasn't awake wondering about pulling power that's for sure.
Thanks for all the help! Sorry it took so long to get back to this topic, two-a-days didn't leave me time to model. Now I can sleep.
To help you sleep more soundly: If my locomotives have sufficient power to manually raise and lower my automatic garage door when the electronic sensors go on the Fritz, then I'm satisfied that they'll pull a sufficient number of cars on my railroad.
Sweet dreams.
Tom
Tom View my layout photos! http://s299.photobucket.com/albums/mm310/TWhite-014/Rio%20Grande%20Yuba%20River%20Sub One can NEVER have too many Articulateds!
hmmm 1:87...mile long train? 18 meter long train...now that would be cool though......especially the likes of donner pass 8 locos on the front 8 in the midle and 6 on the rear.