# Train length?



## noela (May 22, 2008)

Probably been answered many times before, but haven't found the answer.
My question deals with length of trains. 
I have no desire to burn out any of my engines by overloading them, but, I have been experimenting with train lengths.
My layout is flat. Minimum curve is 20' diameter. All cars have steel wheels and ball bearings. None of the passenger cars or cabooses have wiper assemblies to pick up power, therefore no drag. My freight cars are of the 40' variety, and with the exception of a few Overton Style Old timers, my passenger cars are all standard length 85'. I use battery and track power (track power is a 25 amp, 20 vdc Bridgewerks unit controlled through a UR15).
I have seen many pictures of trains double and triple heading to pull 15-20 cars. I have used an old Kalamazoo "Donkey" to pull 15 freight cars, and the engine isn't even warm after 1/2 hour of constant running.
I am trying to figure out if there is a formula, or other available information, that would allow me to compute the length of trains without doing damage to my engines.
Needless to say, any suggestion and/or direction would be appreciated. 
Thank you


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## markoles (Jan 2, 2008)

Noel,

I think what you are talking about is tractive effort. George Schreyer has a fairly detailed comparision on his website. When locomotive wheels start slipping pulling a load, that's when it is time to back off. Becuase there are different drive trains, there is not a good universal formula for what will work for all engines. At this point, it is trial and error. My friends know that I am notorious for seeing how many cars a given engine will pull. I've busted a lot of gearboxes in 25 years. Perhaps this is what you are trying to avoid. 

On the other hand, an answer to your question can be subjective. Double or triple headed trains were common on the D&RGW where grades exceeded 4%. To this day, they still operate that way. On my railroad, I double head steam engines for the fun of it. I don't really need a mallet and a mikado to pull 35 cars. But it is fun, people like it, so I do it. Also, there is less potential for damage with more power.


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## Dan Pierce (Jan 2, 2008)

Some engines can be loaded to the max and run fine. 

LGB Mikados have 2 different versions on the motor drive system and the earliest one is very weak and will slip. I have repaired several of these. 
What LGB did was place a plastic type gear cup on a smooth shaft. Heat will make this slip and if grease or oil gets on the shaft, the motor will 
spin and the engine will not move making the plastic cup not grip the shaft ever again. 

Also, the Mikado has weak wheel to axle adhesion. Seems the axles were designes to have serated ends that do not go all the way through the wheels. These slip and the side rods bind and then break. 

SO, I would never let a Mikado by LGB ever get near the slipping wheel load as something will definitely break.


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## Greg Elmassian (Jan 3, 2008)

The big factor is grade, there is a huge difference between flat, 1.5% and 3% grades. 

Flat with 20' diameter curves should allow you to pull long trains with a single loco, like 20-30 cars with something like an Aristo SD45 with the appropriate weight in it. 

Basically, if you can start and accelerate the train with no wheelslip, you are most likely ok for long term running. 

35 cars is a reasonable load for a good sized loco, weighted in good condition... when you start getting at 40, I would go two locos... 

Again, add a grade and you will need more motive power. 

Just because you can pull something does not mean it's a reasonable load, how warm the motors get is a good indication. 

Regards, Greg


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## PLONIEN (Jul 31, 2008)

Another variable I found is the type & weight of each car. I can pull more freight cars with a single engine such as an Aristo Mikado or SD-70MAC, than I can pull passenger cars. Aristo heavyweight passenger cars are *heavy*. I put eight heavyweights and the engine on the sales one day and it showed 168 pounds of model train! The engines will move that load if you start very slowly, but the amperage meter on the Bridgewerks 25-TDR started to climb to dangeraous levels for a single engine. Add to that a 3% grade climb, and I was betting I would soon smoke the entire electronics in the engine. So, I agree with what has been posted, but add to the variables, the weight you are trying to move. If in doubt, weigh everything on your bathroom scales and if the train weighs more than you do, you are probalby in trouble.


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## aceinspp (Jan 2, 2008)

Yep grades have a big impact on how locos respond. Also the number of cars and if the track is level. I never run more than ten cars per loco as this tends to be the norm for most locos. I will double head locos once I go over the ten car limit weather its steam or diesel. To date I've not burn out a motor yet. I will test each individual loco for my conditions on my lay out to see what the max I can pull before wheel slip. I then determine how many cars I can safely handle so that I do not end up burning up a motor or stripping the gears. Later RJD


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## Ron Hill (Sep 25, 2008)

Noel, my layout is flat and I have 16 foot diameter curves. I can pulll 30 cars with a single USA GP-30 with no problem. But be aware that freight cars do not weigh the same. A Evans box will weigh more than a 3 bay hopper, a aluminum extruded tank car will weigh more than a gon. I ran trains for the Trick-or-Treaters Halloween and it amazed me how much 30 mixed freight cars weigh when I cupoled them up to the locos. I like to run two ICG GP-30's rear to rear not only for looks, but less wear and tear on the locos. 
Ron


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## steamtom1 (Jan 2, 2008)

When it comes to a proper train length, I refer you to Ryan Bednarik, in a video posted on the Live Steam Fourm. It's about an 8 1/2 minute video, but at about 5 1/2 minutes we see Ryan launch his GS-4 with what appears to be a 55 car train. Check it out...


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## Randy Stone (Jan 2, 2008)

I have my layout on the floor in the Florida room so it is realitively flat. I'm using 8 foot diameter curve on the mainline. I've been pulling 44 coal hoppers with either of my RS-3s with no problems. Some of the noppers have steel wheels and a few have loads. I've not had any wheel slip at all. I pulled about 20 hoppers the other nite with my twinn Critters with no problems. With 44 coal cars and a caboose, the train is covering the 8 ft curves on both ends and the 8 foot inward boe of the track on one side. 

Randy


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## Greg Elmassian (Jan 3, 2008)

To add a little to Randy's "calibration", he is talking MDC hoppers, a bit smaller and lighter than your 40' cars. 

Regards, Greg


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## armorsmith (Jun 1, 2008)

Noel, 

I believe there are many factors that govern train length, but this video aught to demonstrate that L-O-N-G trains are possible with a single locomotive. 

http://www.youtube.com/watch?v=QhQMqKl38wU 

Granted, this is one helluva loco, but still .... 

Bob C.


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## Randy Stone (Jan 2, 2008)

Here is a video of my RS-3 pulling 44 hoppers and a caboose 

http://www.youtube.com/watch?v=WyZk7H_TbMs


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## kormsen (Oct 27, 2009)

since my conception, how an oldfashioned train has to look, is mainly formed by wild-west movies - four to five cars behind loco and tender.


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## Steve Stockham (Jan 2, 2008)

For narrow gauge, one merely has to look at what the prototypes are running. The Mikado's of the C&TSRR and the D&S will pull seven passenger cars singly and 13 cars doubleheaded as a rule. The K-27, being the smallest, will pull six by itself (this includes a box car not in the count.) The #315, which was restored to operating condition, runs on the D&S and C&TSRR from time to time and is a C-17 (2-8-0). When it runs, it usually has five passenger cars. The freight runs are also five or six cars (caboose included.) The _Eureka_, a 4-4-0 from 1875 carries _two_ passenger cars. 
Our trains usually can pull slightly more than the prototype comparatively speaking but this will give us a guide by which narrow gauge operations in Colorado ran.


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## eheading (Jan 5, 2008)

I generally pull 12-14 cars with one Aristo locomotive, normally either an SD45 (with two electrical motors as opposed to 4) and/or a GP40 with no problems at all. I have several curves that are 8' in diameter, and one stretch coming into my RV garage that is going up a 2-3% grade and 180 degrees of 8' diameter curves. I have pulled as many as 25-28 cars with one engine, but I normally don't do that, but rather double head on those. I have not seen any problems with my engines so far with those loads.

Ed


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