3% grade question?

[Anonymous]

I'm looking to use 3% grades on a portion of my layout and was wondering if I will have any issues pulling up that incline with my trains. Lets say for instance that I am running 2 GP40's pulling 20-30 cars.

[Anonymous]

Nearly impossible to answer. If I had to guess, I'd say "yes" you will definitely have problems.

To answer properly, you'd need to know many things: What scale and brand of loco is it? Is it properly set up and running optimally? What sort of cars? How long? Are they properly NMRA weighted? What brand(s)? Do they have metal or plastic wheels? Are the trucks free rolling or binding. etc. etc. etc. All these questions would impact it, and the answer will still be a big guess.

But the fact is 3% is quite a grade under any circumstances.

[Anonymous]

Probably going to be atlas or Kato engines, we'll say good running, Not nmra weighted in most cases, standard 50' box cars, mixed wheels but mostly plastic with free rolling trucks, N scale.

I guess I'm asking because it really doesn't appear to be that big of a grade. I would like to raise my track up 4" in about 10 ft. but it is the mainline so I want to make sure that my main engines will be ok on it. Its a triple main so it will see lots of traffic. Any suggestions?

[Anonymous]

You probably find that sometimes a coupler will pull out of one of the lead cars going up long steep grades and pile up at the bottom of the hill, or the cement floor, in pieces. The Geeps will need extra weight added, which will aid in reducing the life of the motor. And if you are thinking of pulling 20 to 30 cars up a long steep grade, figure about five or six locomotives.

You can get away with a short steep grade, say a few car lengths, but pulling such a long train up a long steady steep grade with just a couple geeps in the front probably will end in disaster or stalled locomotives (which isn't good for the motors either).

There are ways around this, if you can not avoid steep long grades (3%-5%), which involves prototype practices.

One is a helper loco on the rear. That solution has its draw backs in modeling, unlike the prototype, if you are NOT using DCC control. If you can't control the helper locomotive speed in coordnation with the lead locomotives, you most likely end up derailing the train. However, DCC is perfect for pusher service. You can control the speed independently of the helper locomotive or match up the performance of the helper loco with the lead units.
You would need a spur at the bottom of the hill to park the helper engine, waiting for the next train.

Another is mid-train slave engine (about 2/3 back in the consist). However with conventional DC control, the problem is with speed control of the slave engine just as with the pusher.

A third solution is called humping the cars. Stop laughing, it's not what you think. It involves splitting the train, at the bottom of the hill, into consist short enough for the locomotives to haul the train safely up the hill. The engines cut off at the top of the hill (after setting the brakes on the consist) and use a run-a-round track to get around the upper consist and return to the bottom of the hill and start again with part or the rest of the consist. Each haul will use the run-a-round track until the consist is complete.

Still another prototype practice would be to split the train into two or three shorter trains. The trains following the first trains are called extras.

Going down a steep grade is also dangerous. You will need more locomotives in front and/or hump the cars as you would going up the hill.

[Anonymous]

Wow thats a great answer, thank you. I have one more question for you. Would it make any difference to run larger engines like Dash 9's or SD70's?

[selector]

Don't forget that part of each end of your 10' will require transitions (hence the warning about the decoupling), so your rise will have to take place in about 7', meaning that your grade might be much steeper.

[Anonymous]

Remember, theres allways helpers.

[tomikawaTT]

Maybe I'm a contrarian.
I don't see a 30/1000 (3%) grade as any big thing, unless your cars are loaded with gold, platinum or depleted uranium. I'm using that grade to climb out of hidden staging, one loco pulling fifteen cars in HOj - the loco is not superweighted and the cars are metal. (So are the wheels, and they are very free-rolling.)

The only way (short of building the actual trackage) to find out if your rolling stock will handle that, or any other, grade is to build a test fixture and try it. You may be pleasantly (or unpleasantly) surprised.

Incidentally, if operating a scheduled train in two or more pieces, all of them are called sections and recorded on the train sheet as "first-xxx," "second-xxx," and so forth. All but the last section must show green flags by day and green classification lights by night. Extras are created by dispatcher fiat, and must carry white flags or show white classification lights.

[jondrd]

[2c] Whatever you do don't aggravate the situation by a curve while climbing. Per advice already given: this is an instance in RR and MRR where less is more.

Jon

[Anonymous]

QUOTE: Originally posted by jpaauwe

Wow thats a great answer, thank you. I have one more question for you. Would it make any difference to run larger engines like Dash 9's or SD70's?

A six axle may give you a wee bit more traction and more electrical pic up but the motor and gearing are the same as in a four axle, given it's the same model manufacturer.
Other than in a switcher, I don't recommend regearing. I've heard feedback from other modelers that it slows down the locomotive too much for their taste. Most model locomotives made today have the best running gear availble, so you don't have to fool around with remotoring. Some pull better than others and I'm sure you can find plenty of facts and opinions on that subject if you ask.

[Anonymous]

QUOTE: Originally posted by tomikawaTT

...I don't see a 30/1000 (3%) grade as any big thing,.....and the cars are metal. (So are the wheels, and they are very free-rolling.)

That's true. A 3% grade is steep but not too extreme in model railroading as it is with the prototype. Pulling 20 -30 cars will tax the couplers and motors though.

Also free wheeling wheel sets are a must. If you can afford it, you can replace the whole truck with a free rolling set or replace just the axle/wheel set. Measure the length of the axle you are replacing before buying replacement metal wheel sets. Whether you are replacing the axle/wheel sets or keeping the originals, a TRUCK TUNER tool is handy to have or use a #11Xacto blade to remove any casting flash from the journals. Plastic trucks are self lubricating, but on metal trucks I give the journals a drop of Lock Ease graphite lubricant and allow it to dry before installing the wheel sets .
Be sure the wheels are in gauge, using an NMRA standards gauge.
Attention to the couplers is important too. Make sure that they are secure in the draft box, the correct height, including the uncoupler pin, and that the coupler doesn't droop.

QUOTE: The only way (short of building the actual trackage) to find out if your rolling stock will handle that, or any other, grade is to build a test fixture and try it...

Great idea. A pull gauge is a part of that.

QUOTE: Incidentally, if operating a scheduled train in two or more pieces, all of them are called sections and recorded on the train sheet as "first-xxx," "second-xxx," and so forth. ......

[D)][oops] That's correct! They're called sections. An extra is a train that's not regularly scheduled. I stand corrected, thanks.