How many cars should a good engine be able to pull with out hurting it self?

Model Railroader General Discussion (Model Railroader)
1

I hope the answers will not be as dumb as the question sounds![:D]

I know there are a lot of factors that comes into play with what a engine can pull. Weight, motor, drive wheels, how free the rolling stock rolls, radii of turns, power supply and finally grades.

For what ever reason I seem to have a lot of problems with engines breaking down. To see what span this question look in the DCC section.

I do re lie a lot on the reviews in magazines, but could the reviews be a little kinder than they should be? For you old gear heads like me when Hot Rod magazine reviewed a 69 Road Runner, 4 speed, 4.10 gears drove by Ronnie Sox’s could cut 12.9’s stock as a rock with slicks? I know that was BS being a Mopar racer.

Or is more like it can pull 80 free wheeling car’s on a level and straight track, but if you do it for 3 hours it going to hurt something?

When I was DC and ran only Athearn BB engines I had a few problems, mainly having the flywheels slipping on the motor, had a few rotten motor mounts.

Now in DCC, I melt wires, melt decoders, one steam engine drive wheels came out of quarter and another one likes to crack tower gears.

I think I am buying good engines. All my Steam is either BLI or PCM, Diesel are Proto 1000’s, Proto 2000’s, Blue Line, Athearn RTR and few old Blue Box Athearns that just keep on going, and going and going.

I do like longer trains, a normal diesel train on the main line is 30 to 45 cars over 45 they are doubled headed. Steam is 25 to 30 cars not counting the PCM Big Boy or Y-6b which is 45 to 60 cars.

I am 98% sure the track is wired right except may be the turn outs. No shorts, but I never powered the frogs. I am HO scale, DCC Bachma

2

Ken, I don’t know how much I can help you, but you run trains about three times the length that I do. I only ever ask my Y6b to pull 19 cars up my 3% grades. I couldn’t tell you how close to the maximum that is. What I would suggest is that if you demand that the electric motor draw near its maximum rated amps most of the time, you can expect that it will at the same time generate a lot of heat. Heat is the enemy of electronics, and static discharge for some of it, too, I guess. But heat is the one we should be concerned about. When a relatively unsophisticated and inexpensive (not NASA specs) can motor gets really hot, it must accelerate it towards its eventual natural engineered end, don’t you think? It’s no different from a 426 Hemi. Run it hard and hot, make it produce all the rated 400+ ponies, and how long would you expect it to keep turning over?

That’s about the can motors. The other drive components are much less sophisticated, and hardly count as bushings or bearings anywhere. If these beasties has decent bearings and bushings, they’d probably cost us about 20% more than they do, maybe more. So, you are making a drive system, motor and gears and pins and rods work near their max much of the time.

It can’t be good for them for very long. One other thing; I probably run any one engine less than 1/4 of the time that I think you do. I don’t believe even my oldest engine has more than perhaps 2 hours total on it.

That is how I see it. Maybe I don’t have an accurate picture of your actual running style, but I have always felt, based on the way you describe your experiences, that you demand a lot of your engines.

-Crandell

3

It does sound like you’re running your trains pretty hard.When I worked at Dunham Studios, the standard practice on display layouts (like Citibank Station), was to run a train for an hour, then let it rest for 10 minutes (to cool down), run an hour, rest 10 minutes, etc. Running trains 8 hours a day also required a lot of extra maintenance, we would break down an engine, clean and relube it every 2 to three days, (16 to 24 hours running time). In my days there we ran mostly Athearn, Mantua and LL P2K (early), these all had fairly heavy duty drives and motors compared to today’s stuff. Also, motors, as they get hotter become less efficient and have to work harder and use more current to provide the same pulling power. A motor when cool may only draw .3 amps, but when it’s hot it can draw double or tripple.

Multiple-unit lashups help to spread the load and can extend running time…With 30 to 40 cars you should at least be double heading, tripple heading would be better. On my layout we often run 70-80 car trains, but they’ll be headed by at least four six axel locos if not 5 and they never run for more than 30 min to 1 hour, we then break the train down put another together with fresh motive power and run that train for a while. We usually have 3 or 4 trains like this running (plus yard and locals) on my 5 amp DCC system. I have yet to burn up a motor or decoder or melt any wires. And all my frogs are dead too.

As far as melting wires, I would say that that is due to your 8 amp booster. That’s a lot of amps! How many trains are you running at once? With 8 amps, should anything go wrong, like an engine stalling or derailing or motor binding everything will heat up and all the current will find the weakest point, which is usually the wires or the cpus on the decoders. Most boosters, while they have good short circuit protection, don’t have good thermal protection and the decoders don’t have any, therefore the wires melt.

4

Ken,I hope you are sitting down…At the Bucyrus club I can run 2 BB GP38-2s and pull 18-20 cars on the “front” layout which has 2-2 1/2% grades with zero problems during the 8 day county fair running at scale speed for 6-8 hours a day…On the back layout-0% grades-these same locomotive will pull 30 cars.My Atlas locos will pull 22 front layout and 40 back layout.Now during the fair I use 3 BB GP38-2s and pulled a 37 car train on the front layout for 7 hours with zero problems.

Here’s my"secret" that really isn’t a secret…All my cars are stock weight with free rolling wheels,locomotives are well maintain and speed is a scale 40 mph on the back layout and around 25 smph on the front layout due to the constent up and down grade-the only “flat” land on this layout is along the front of the layout.

At the other club a 3-4 unit consist on a 40-50 car train is the norm.

My BB SW1000 and SW1500 will pull 22 cars in the yard while my BB SW7 will pull 17.My Atlas S4 will pull 30 as will my RS1s.My BB extra weighted GP7 will tote 28 cars.

If you look in the mirror you will see the majority of this train is still on the upgrade while the locomotives is heading down grade.This is that 37 car train I mention.

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With your DCC system, are you able to set CV’s?? If not, I wonder if part of the problem is running engines together that aren’t properly speed-matched. In DCC you should be able to set two engines up so that they start, run and stop together almost perfectly as if they were one engine. If one engine is way off from the other, it can cause problems.

Also, if your engines can do it, it’s fine, but I’d say 30 cars are a lot for a model engine. I’ll run a 30 car ore train with a 2-10-4 or 2-6-6-2 but for diesels I generally use two engines for most trains, even moderate (10-12 car) freight trains. I find two speedmatched engines seem to run better together than one separately…two engines splitting the load just seems to work better in my experience.

Think of it like carrying a load yourself. One person carrying something weighing 50 lbs is going to do a lot more work than two people carrying the same weight together.

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Stix said:Think of it like carrying a load yourself. One person carrying something weighing 50 lbs is going to do a lot more work than two people carrying the same weight together.

While that is true try telling that to a foreman…[(-D] After all a worker should be able to carry 50 pounds and thus it is with locomotives…All of my locomotives is very capable of pulling 20 cars on the flat signally but,should they? IMHO no because 2 engines on a 20-25 car train looks about right.25 to 40 I believe 3 engines looks good.40-50 cars should require 3 six axle or 4/5 four axle locomotives.

A yard switcher should break the train down instead of a SW7 pulling 20 cars it took 2 big road engines to pull.My favorite cuts for a single switcher is 8/12.On a 50 car train its two 12’s and two 13s.Now if I am using say 2 SW1500s then its two 25 car cuts.Again it just looks more realistic.

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I’ve run trains about 40-50 cars long at train shows for 7-8 hours straight with no problems. These are with Proto, Atlas and Kato loco’s. If I add more loco’s the trains get longer. Even my GO train with a new Athearn RTR F59PHI has run for 7 hours non stop pulling a 8 car Bombardier passenger set that weighs a ton with no problems with heat. I think your problem could be that your locating your decoders to close to the motor, your pushing 8 amps(over kill in my opinion, 8 amps should be left for the O and G scale guys) and when you have a derailment the motor is sitting there stalling and producing an enormous amount of heat. Your a car guy so think of it like a trans brake. When its on the motor has such a huge load on it that it produces large amounts of heat. It only takes a couple seconds for your trans temp to go through the roof and that is what is happening to your loco’s. The motors are getting so hot that they are melting wires and decoders. If I were you I would try to insulate your decoders and keep them away from the motors, lose the 8 amp system you have and stick to 5 amps and finally look at your cars. In another post you said you prefer to buy TYCO cars and fix them up. Not to start any flame wars or anything but in my opinion TYCO is junk, your better off buying better quality items right from the start then trying to fix up a TYCO car because you will get a better rolling, better looking and an over all better performing car. If you take a Athearn Genesis, Intermountain or a Atlas car 99% of the time they will roll so free that if you sneezed on one it would move. Now take a TYCO car and you basically need to push the thing to get it to move and thats after you work on it. Think of the drag that is being put on your loco’s from those cars, its like going drag racing with your parking brake on. Sure your going to get down the 1/4 mile but your engine is going to run hotter then it would if your parki

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Cuda Ken, Not to pick on you [:-^], but you have made quite a few posts about locos failing. It seems that rather than bad locos, you are overworking your motive power!! If you had to move 10 tons of dirt, which would be better, an S10 or a tandem wheel dump (being a car guy)? Another comaprison would be like putting a 6+ litre diesel in a VW bug body - the engine would kill the body!!

Simply put, yes, the loco should be able to move 25+ cars, but for how long? My suggestion, RUN SHORTER TRAINS!! OR PUT MORE LOCOS OUT FRONT!!!

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Lou said:Simply put, yes, the loco should be able to move 25+ cars, but for how long?

24/7 if needed…The thing is the cars must be free rolling and the locomotive well maintain…Add scale speeds to the pot and you’re good to go.

See these CN Bachmann locomotives? They run 14 hours a day during the 8 day fair pulling either a 20 car stack train or a 25 car freight train at unrealistic high speeds.

So,I agree there is something amiss with Ken’s locos…

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I read a couple of interesting comments on the 8 amp booster you have and that you should get rid of it. I will chime in with my two cents here. Going to a 5 amp booster will do nothing to help with the problem for the most part. Remember, amps are drawn and voltage is pushed. In other words when you turn the system on there will be a certain voltage at the rails but, untill a load is put on the system there is no amps. Now, place an engine on the tracks and start to run it and there will be that load on the booster. If the engine is drawing 1 amp it make no difference if it is a 5 amp or 8 amp booster. Now the booster will have it easier if it is rated higher but, the decoder/motor still is only using 1 amp at X voltage. To use the car analogy…the fuel pump pushes a certain pressure regardless of demand (Voltage) the engine draws a known amount of fuel at any given RPM or load (Amps). The throttle (decoder) regulates the volume (current (Volts x amps)) of fuel into the engine. As long as the fuel delivery system (wires, rails, etc…)can supply that fuel the engine will perform properly. The big difference here is that electric motors and associated wiring do not follow the physics that a fuel delivery system in a car does. In a car, if you push the system too far it will starve for fuel as the delivery system won’t be able to deliver. In electrics though, the load will try to pull more thru the wires than they are rated for. This is where the heat comes from. Under normal (need a definition here) operating conditions the decoder manufacturers have the wire rating well within the needed spec. However, at stall (motor does not turn at full voltage), the motor is almost in a dead short situation and the unit is trying to pull all available amperage and will until the circuit protection will trip. This could explain the decoder/wire issue you are having. As far as the mechanics go a couple of people here have explained it pretty good. To add to it though

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Ken–

I’m DC and brass, so I don’t know if this is going to be of any help to you, but I judge the length of my trains on the size of my locos. For instance, if I run a long train, which on my layout is about 25-30 cars, I make sure that the train is being hauled by one of my big, heavy articulateds. If I’m going to run non-articulated steam, I usually run a train half to 3/4 that length. Even less for smaller wheel arrangements such as a 2-8-0 or 2-8-2. If I want to run a longer train with non-articulateds, then I make sure I double-head them. And I don’t run them to death (sorry about that), they make at the most two laps around the layout before I either break the train down or change out the motive power–which adds to the fun of operating, anyway. That way my locos are shoving out their max power for only about 10 minutes before change-over.

I’ve got fairly easy grades (2-2.5% on the layout and pretty generous radii (34-36") so I don’t have the tight radius problem that can add to the load of a larger locomotive.

I know that longer trains of from 40-80 cars look really impressive, but if your track is broken up with cuts, tunnels, bridges, etc., a 25-car train can look just as long, because you’re never really seeing it in its entirety. I notice from your photos that you’re starting to put in scenery (and some really nice scenery, BTW [bow]). You might consider some rock cuts and short tunnels, also. That will visually break up your trains and you might find that you don’t need such long trains behind your big power.

Just some thoughts.

Tom [:)]

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Cuda Ken

It’s not a dumb question at all. And if you read Joe Fugate’s web site carefully you will see that he has had realiability issues with locomotives over the long term, too. I think there are several factors at work.

First of all, if you are going to load your locomotives down, get an ammeter. You need the special version for DCC availabe from Tony’s. With can motors, I would very reluctant to allow them to draw more than 0.4 amps for hours on end, and 0.3 amps would be even safer (but probably not achievable with long trains). Any time a locomotive with a can motor starts drawing 0.5 amps or more, it needs to be taken out of service and “tuned”. By tuned, I mean lubricated and mechanism adjusted (if necessary) to get the light load current down around 0.3 amps. Once the light load is 0.3 amps or less, adjust the number of cars to keep the draw at 0.4 amps or less for extended running. 0.5 amps is probably OK for durations of an hour or less. Free rolling trucks make a big difference in allowable train length.

The guys who run Lionel trains for consecutive 8 hour days at shows have specific daily lubrication and maintenance schedules. They have also found automatic transmission fluid (modern plastic-compatible type, not left-over from the '70s) to be the longest lasting gear lube for display running. That is where I 1st found out about ATF for gear lubrication.

Another real but left unsaid issue is the construction of modern model locomotives. The old Mantua steamers had real brass sleeve bearing inserts where the axles were mounted in the frame. Boilers were cast metal with plenty of weight. The motors had bearings that could be user lubricated, and the brushes could be adjusted and/or replaced. The worm was made of a harder material than the worm gear for reduced wear. Hobbytown of Boston diesel drives were similarly famous for their durability and pulling power. I don’t see today’s plastic model locomotives being built with the same durability in mind.

13

Some good points raised above that I would like to capture at this point.

The total amps that the system is able to put the rails can only be maxed out as power-drawing devices (switch motors if on the same system, lamps in passenger cars, and the can motors in the various engines underway at the time of measurement) are demanding of it. If your system has an 8 amp capacity in total, and you have two Big Boys chugging along hauling 40 cars each, you will be drawing about 1.5-2 amps total. That should not affect your wiring. But, if you run many engines concurrently so that your system is maxed at or very close to 8 amps for an hour or more, you should expect feeder wires thinner than 20 gauge to be darned hot! If a short near a pair of feeders takes place you have real problems!

Secondly, to add to Tom’s points above, or really to amplify one of them that I didn’t mention in my first reply, curves that engines have to work hard to get through due to a bit of pinching in the gauge or because they are close to the engineered minimums really cause a spike in current draw…a ramp meter would show a sudden rise in the amperage running through the rails, I believe, and certainly your decoder is going to flow that through to the needy can motor…which will use it ! Amps yields heat! More amperage yields even more heat!

So, it seems that it isn’t going to be a simple, one-shot, solution for you, Ken. It will probably have to be a bit of modification on at least two fronts.

-Crandell

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Well let me add this…First our locomotives are a lot tougher then most think-ask anybody that has ran trains for hours at train shows,mall shows,county and state fairs…What we do at the Bucyrus club during the 8 day county fair should be evidence enough.This doesn’t include the other open houses that may be 2-3 weeks apart.I done this for the past 2 years with zero maintenance problems,no burned out motors and no brush replacement.My equipment averages 52 hours of run time during the fair and when I see Bachmann run 14 hours aday then I know the wear is small-if any…

Now let’s get to the bones of the matter…8 Amps is enough to fry alot of motors or melt decoders and is overkill…Little or no maintenance can wear locomotive parts out espeically if the locomotives are ran at high speeds…

That I believe is the heart of the matter.

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Hi Ken,

this is a great subject. My question for the producers of motive power is the following: what is the amperage rating of the motors in the locomotives? Then at least we could figure out how much load these motors could take and not worry about burning anything out.

From my personal experience each manufacturer has one or two types of electrical motors that they put into the locomotives and it does not matter if it is four or six axle engine. The rest of the drive train for the most part is also identical. So this then makes me wonder what kind of electrical motors are in your big steamers like the PCM Big Boy. Are they identical to those found in the diesel engines. If so then it is no wonder that there are so many issues with these locomotives. A much higher weight enables the engine to pull more freight cars increasing the current draw prodcing more heat and this starts the cycle of break downs. The propulsion system is not designed for the model. So basically these large steamers were designed to run for short time periods with prototypical freights and then you are still pushing the drive train. If you do not wish to have major issues with them then it would make sense to have these large steamers pull smaller trains then the Diesel engines that have the same electrical motors. I say this because it must take more effort to move a large heavy steam engine then a diesel where there are no rods and such to move as well. Considering the price that one pays for them it is a real shame.

That is at least the way I see it.

Frank

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TA462, I have around 300 rolling stock now but only around 40 are TYCO. I got hooked on Old Dutch Hoppers for some reason and have 32 of them. They all have weight added, Kadee couplers, tuned trucks and PK 33" wheels.They will roll as well as any of the higher end brands you listed. I do not prefer them, but I never found a Intermoutain Old Dutch Hopper.

Pike-62, you took the posting right off my keyboard about the 8 amp power supply. If a decoder is rated 1.5 Amps/ 2 Amp Peak and I only have 3 amp power supply there could still be a problem. I normally run 3 lines with one engine each and most of the time 2 will be sound and one none sound.

Far as run time Crandell and Tom are right, I run them a lot and for hours at a time. Far as lubing, all I have ready to this posting is to much lubing can cause problems. If you happen to go to the DCC section and looked at that post the two engines that caused me to post this questions are both Athearn RTR, one is a SD 50 and other one is a Dash 9. I am sure there is something wrong with the SD 50, rather it be a bad motor or something in the trucks to cause it to draw way to much power. My Athearn fleet do seem to need more maintenances than the Protos.

I want to thank all for the time and effort it took to post well thought answers.

Cuda Ken

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Ken–

I’m going to go WAY out here on a limb, I suppose, but I’ve never understood why contemporary steam models are geared like Diesels, with all those towers and reduction gears. Most of my brass locos, which have been running really well since the 1960’, '70’s and up, are geared from motor to driver gear. No vertical shaft drives from motor to driver gears, no complications to drive you nuts, no “All Wheel Pickup” with split axles, just the occasional tower with brass reduction gears, pickup from one side of the loco and one side of the tender (and in my case additional bronze pickups added because of my particular garage location) and lots of ‘heft’. The more I hear about the problems with contemporary steam plastic models and their gearing, the more I’m convinced that simpler is better. Okay, most of my locos don’t crawl at 0.5 mph (why should they to begin with? What’s the Big Deal with watching them take five minutes to run from tie to tie?) but they get up and go and they haul at nice scale speeds and they haul well.

Like I said, I’m strictly DC, so I don’t have all the sound and stuff, but my locos can haul a train and do it well. As I said, I usually change them out after about 10 minutes, but if I chose not to, they could probably haul the same train all day and only warm up the firebox, not fizzle out because the gears stripped.

Okay, I’ve vented.

Tom [:D]

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Cuda Ken, Season’s Greeting’s from a fellow Missourian. I too have several Tyco frieght cars for the same reason you mentioned. I suddenly got addicted to purchasing Schlitz reefers off of Ebay. I also did the same with them as I do with all my rolling stock, add Proto 2000 or Intermountain metal wheels and Kadie couplers. They run ok, but I won’t be getting anymore as I cant live with the level of detail. I now purchase Athearn BB kits or better.

19

Check the motor temperature after a bit of running at load. Electric motors attempt to keep turning. As the load on the motor increases, the motor draws more electric current to carry the load. As long as the extra current doesn’t get the motor too hot, all is well. My rule of thumb for anything electrical is to lay the back of my hand (or a finger) on the device. If I can keep touching it for the count of ten, it’s cool enough. This works for motors, semiconductors, resistors, just about anything. It works better than ammeters. Long as the motor is running cool, the current is OK. If the motor gets hot, it doesn’t matter what the current draw is, it’s running too hot.

As long as the motor is cool, the entire locomotive is cool. Frictional wear on the moving parts (gears, worms, bearings, side rods, etc) is about the same whether the engine is pulling anything or not.

20

If you use 12 volt lightbulbs in your buildings, but run them on 6 volts, the bulbs lighted with half power are going to last significantly longer. Similarly, at least in my mind, if you have one engine straining at it’s limits to pull a long train at full power and two engines each running easy at 50% power pulling the same length train at the same speed, the engines running at half power are going to be less prone to problems than the one pushing the limits of it’s pulling abilities.