Large Scale Central

What limits train length?

General Discussion
#1

What is the limiting factor on how many cars I can have in my train, track power or the engine.
If it is the engine then; how many cars can my ALCO PA-B engine pull realistically? Christmas is coming and I will be asking for friends and family to by some cars for me and just wanted to know how many I can use.
If it’s track power, I have yet to tackle that issue.

And can someone tell me the if the cars all should be the same length. I see some cars/tankers that are listed as 40’ 50’ up to 70’. I imagine the answer is it will ultimately be up to me, but I am just looking for some aesthetic, realistic opinions from those of you who have been doing this a long time.

Thanks,
Shelley

#2

Clinton HHMMM don’t you have a Stone dam and Weabix !
That’s if you’re in mass.
It’s you’re railroad run as many as you want!
If that’s a USA PA you need a lot of power just to move those beasts!
Pasenger are usually the same lenght, but freight is it’s own animal!
Just run what you like!
Sean

#3

Run as many as it can pull, without “letting any smoke out” In other words experiment, just don’t overdo it!!! Check around on USA’s site they probably can tell you I have the same units and pull PA/PB and so far run 5 other of they’re pass cars behind it. Check out my video on you tube of it. Regal

http://www.youtube.com/user/7485jerry

#4

sure, i agree - run, what you like!

trackpower seen as system is no limiting factor. it can be, if your powerpack is weak, that you can not run more than one motorized loco.

the engine is one of the limiting factors.
specially:
a) the gears. many locos have plastic gears. a load, that is too heavy could break them.
b) the weight of the loco. if the loco has to tow too many cars, it may just slip on the rails. - you can fix that by putting some lead inside the loco. then it gets a better “grip” on the rails. (if you put too much additional weight, watch out for “a)”.)

there are two other limiting factors, i can think of:
curves - the sharper the curves, so much bigger the braking factor of the cars being towed against the inner rail.
grades - the steeper a grade, less cars can be towed.

well, other than that, there is the ultimate limiting factor: the length of your loop. ;-)))

it is very hard to give you real advice or a number of cars possible. there are many factors, that vary from one layout to the next.
(plastic- or metallic wheels, weight of cars used, quality of trackwork etc…)

#5
shelley sherbondy said:
And can someone tell me the if the cars all should be the same length. I see some cars/tankers that are listed as 40' 50' up to 70'.
Should all cars be the same length? No. Especially when talking freight cars.

During the era your PAs would represent, late 1940s through 1970s, there were 40ft & 50ft boxcars; 40ft & 50ft Hi-cube boxcars; 40ft & 50ft gondolas (not sure when 57ft mill gons came out); 40ft & 50ft flats; and so forth.

Covered hoppers are kind of a special case as some of the shorter ones were for hauling cement and were short on account of weight and axle-loading issues.

There were also as far back as the 40s, maybe even the 30s, longer 50ft boxcars, often with double doors, for hauling lighter weigh but bulky items, sometimes even automobiles.

Towards the 70s to 80s end there were boxcars of something like 86ft for hauling auto body parts from subcontractors to assembly plant.

Generally speaking, car lengths, and capacities, started increasing after WW 2.
So, the closer to 1940s, the more shorter cars; the closer to 1970s, the more longer cars.

#6

Sean Yes they are USA’s, and when you say they need alot of power can you elaborate and possibly with specifics on the power needs for this engine. I am planning the track layout over the winter and come spring time will look to lay the track and buy the power then. I have been looking at the Bridgwerks -->MAGNUM 220RM: 20 Amp 2-Track Manual Controller.
Any thoughts on this?

#7

Seems like you got some good advice already so I’ll just say
Welcome Shelley!

#8

Don’t forget that passenger cars ranged from around 70 feet in length to around 90 feet in length in standard gauge.

The true limiting factor of how many cars you can pull will be the design of you layout. Will a long train look ridiculous, with the locomotive chasing the caboose, about three feet behind? Or, if you are fortunate enough to have a larger layout, will your PA and two freight cars and a caboose get lost? How long are the passing sidings?

In any case, welcome aboard, Shelly. This is the place where you get your answers questioned. Bart has the coffee brewing and there is a place for you by the fire. Pull up a chair. The 10:27 is late again, so we have time for a story or two.

#9

small or weak powerpacks have just 1 Amp. so that bridgewerk you are considering will not be the limiting factor.

#10

Usually, the number of cars I have. Occasionally, the distance around the short loop back to the crossing.

#11

Shelley so far you have ben give all the advice I could think of. I have the USA PA/PB set up and love it. I have had 20 cars behind them and could go more, but then again I have a 0 grade loop I run on with 16 and 20 foot die curves.

hope this helped and welcome

#12

I stripped the plastic gears in an LGB Mogul (the ubiquitous #6 Colorado Southern) trying to pull more than 13 USA reefers around a 180’ mainline with a 1.5% grade. I have easily pulled 20 reefers with a USAT SD70-MAC on a friend’s flat layout with big curves. The limiting factor on my layout is the length of the passing sidings (each about 15’). Oh, yes, I have weighted down my reefers with little bags of sand (cheaper than lead) so they hold the track, but then that makes a heavier consist for any given loco to pull. A friend has pulled 48 cars on a flat layout with two lashed up USAT GP40s.

#13

In order to answer this question, which depends on many factors, you should start by telling us everything you can.

Your maximum grade, and the length of the grade would help. That’s one of the biggest factors.

USAT PA’s don’t draw any significantly greater current than anything else. I have 5 of them. I have an ammeter on my layout. There’s some unusual characteristics of some USAT locos, which seems to have evolved into the saying that all USAT locos draw a lot more current.

Another factor is if you are still running the traction tires on your PA’s.

on the flat, with reasonable curves, you should be able to pull 40 cars. Up a grade that decreases sharply.

Regards, Greg

#14

In most cases the length of a train is governed by the longest passing siding. However, if you do not have any passing sidings, then you are only governed by how many engines and cars fit on the track.

#15
Ric Golding said:
In most cases the length of a train is governed by the longest passing siding. However, if you do not have any passing sidings, then you are only governed by how many engines and cars fit on the track.
Or what looks good to you. Not having large, expansive curves, any more than 6 cars on my RR looks goofy to me. Ralph
#16
Ralph Berg said:
Ric Golding said:
In most cases the length of a train is governed by the longest passing siding. However, if you do not have any passing sidings, then you are only governed by how many engines and cars fit on the track.
Or what looks good to you. Not having large, expansive curves, any more than 6 cars on my RR looks goofy to me. Ralph
WOW Ralph has rooster on his railroad..... :)
#17

Ric Golding said:
In most cases the length of a train is governed by the longest passing siding. However, if you do not have any passing sidings, then you are only governed by how many engines and cars fit on the track.

The tails of my wye are my limiting factor; or of I plan on ‘doubling’ the wye, then the grade leading to the front yard is my next limit. No one has mentioned couplers. Especially if you have grades, couplers can be a limiting factor. Even on the flat, each brand has a limit of how much weight it can draw before failing. This wreck was a result of too much weight on a Bachmann coupler going up a steep grade…

(http://photo.cvsry.com/Derail1-640.jpg)

(http://photo.cvsry.com/Derail2-640.jpg)

(Apologies to the regulars for showing this for the hundredth time :slight_smile:

#18
Jon Radder said:
This wreck was a result of too much weight on a Bachmann coupler going up a steep grade...
Oops, time to call the "hand of God" big hook!

Uh-oh, appears kingpin might have broken off the box car.

#19

Forrest Scott Wood said:
Oops, time to call the “hand of God” big hook! Uh-oh, appears kingpin might have broken off the box car.

Yes, and Yes…

(http://photo.cvsry.com/Derail3-640.jpg)

#20

Good couplers should be a given if you are going for long trains. I pull 45-50 cars up a 3.4% grade with no couplers pulling apart.

So, I think in trying to answer the original question, it’s still grades, minimum curvature, and locomotive pulling power.

Regards, Greg