GRADES & BRAKES

[Anonymous]

We find we need to climb 15.5 inches over 15 linear feet with our gargraves (steel, not stainless) track. That is an 8.6 percent climb. (About 4-X worst-case prototypical we know, but tin-plate MUST have some compromises)

Head end power ranges from early magnetraction thru MPC rubber to current Williams etc.

Road limit consist is ten feet except for our cross-country heavyweight which is nearly fifteen feet with a presidential campaign car "tacked on"..

Some of our unit trains (such as stacked COFC) have quite heavy cars in them. (True "tonnage" not computed and we hope not to have to)

ARE WE HEADED FOR TROUBLE?? TRACTION OR OTHERWISE??

Anybody know the spec or call-out for a high duty-cycle electro-magnet that can act as a rolling stock brake on that grade while the head end cuts off to do a set-out??

Thanks for all the help in the past, especially you BIG-BOY!! The Classification and transfer yards came out great thanks to your help.

Joe

[Big_Boy_4005]

Joe, you know me too well, it's topics like this that I live for. I put my answer over on MR, cause I saw it there first.[swg]

[Buckeye Riveter]

Joe, 8.6% grades are steep. In the mountains an 8% grade is hefty for a highway vehicle let alone a flanged steel wheeled vehicle.

I really doubt it would work satisfactorly. A little dirt on the track and nothing would work right. Of course, the wrecks at the bottom of the hill would be spectacular.

If you are interested in testing your engines traction, why don't you set up a test grade to see what maximum grade will work. On another note, Woodland Scenics has a product that lets one construct grades. I think the max is 3%. That is a pretty good hint to what works.

[Big_Boy_4005]

yeah Buck, I like to say that 4% is the practical max. The Lionel trestle set gets close to that over part of it's rise, when installed per the instructions. A couple of weeks ago I was on a layout tour sponsored by the local NMRA.

One guy had a very steep hill on his layout over 3.5%. I watched as one of the guys who was operating found his train stuck half way up. He hollared to one of the other guys to send a helper, but the reply came back, none available. I said "why not double the hill", he said "good idea."

So he grabbed a coupler pick, and wedged it in the track to hold the back end of the train, and proceeded to take the front half up the hill. One small problem, the siding at the top of the hill was facing the wrong way. He pulled into the siding, and then 0-5-0'ed the engine back to the main to go back for the rest of the train.[#oops]

If you aren't familiar with the term 0-5-0, just count the fingers on one hand. Yes he picked up the engine. The guy whose layout it was was busy talking to his other guests, so he didn't see. [swg]

[3railguy]

I agree that 4% is the maximum you want to go. 5% is pushing it. 8% will give you trouble unless you are pulling a 4 car train.

[spankybird]

Keep in mind that at some point the trains is going to be coming down that grade. [:-^]

Will still be on the track at the bottom [?]

tom

[waltrapp]

To mention one more: I have a 4.3% grade and have occassional uncoupling problems when the train transitions from going up the ramp to level . Mostly this is an issue with my steamers and their tenders - the hook piece comes out of the hole.

There are occassional problems at the bottom but not often. I just keep my steamers off of the hill.

At >8% this issue might be a problem with ALL your equipment. You might want to experiment like others have suggested.

- walt

[Anonymous]

I can't recall where I heard this tip. You can put some 10wt- 1ohm resistors on the bottom grade. Then they would slow down the train, with making a separate block that is connected to the same posts as the block before it. If you are still confused, Ill just make a diagram.

[cnw1995]

Wow, Joe, I would love to see the trains try to take that hill. I have some minor grades (1-3%) due to the imbalance of the rock below the crawl space where all my foam boards sit and boy, is it noticeable - both pulling up, and as Tom mentioned, going down. I like 'em because they give you something to have to jockey the throttle about. I recommend testing it if possible.

[lionelsoni]

For the set-out problem, how about a trailing-point switch down the hill below the train, leading not to a siding but immediately to a bumper?

Or a trailing-point switch just below the siding, with a substantial chock soldered onto the inside diverging rail far enough downhill from the points so as not to interfere with the sideframes of rolling stock on the main line. The front truck of the front car would move sideways, but only about half an inch, to reach the chock. You could cut away most of the rest of the switch, if you like, or make it look like a disused siding.

[wrmcclellan]

joekenick,

Check this link from a posting back in July. Some recommendations (number of cars, etc.) and commentary for a 3.5% grade. I think at 8% you will have some difficulties. Like the others said, you should run some tests.

http://www.trains.com/community/forum/topic.asp?TOPIC_ID=19262

Regards.

[Big_Boy_4005]

Guys, Joe also posted this on the MR forum. One of the members there called my attention to the fact that Joe's math is off. The resulting grade is actually 11.6% which is practically impossible.

[Anonymous]

WOW!!
As always when I post here I get much more than I bargained for. Thanks all.

It'll be back to the drawing boards for us now.

BUT, while my math (and most anything else I do these days) is always suspect, this time I think I was correct.
Fifteen point five will indeed go into 180 some ll.6 times.
BUT 11.6 is NOT 11.6 percent of 180, it is only 8.4 percent of 180. The number 180 is our "hundred percent value" for this example.

I will do some grade and traction testing with a stretch of track on a sixteen foot plank and report the results.
Thaks again guys,
Joe

[Anonymous]

On our former club layout we had a 4% grade runing from our main line to a
lower yard and town.climbing the grade was as tricky as coming down as was
a steep grade and sharp curve but we found anything is possable.

Thank God for the freedom we have

David

[Big_Boy_4005]

I'm sorry Joe, it was late, and I fell for Tony's math. He did simple division, which was wrong. It goes "units of rise per 100 units of run". You did indeed have it correct, though it is still torturously steep.

That is made clear when you extend the length out to 200", as the end height at that length of run based on 8.6% would be 17.2" and not 23.2". You are not rising 6" in the extra 20".

Shame on me, I'll go and tell Tony the bad news.[swg]

[Buckeye Riveter]

To be exact the percent grade is Rise/Run
(15.5 inches/ (15 feet x 12 inches/foot))/100 = 8.6111111%

Tomorrow we wil have a lesson on how to calculate the parabolic curve between a plus grade and a negative grade. It will be exciting!

[Anonymous]

Ok heres the diagram on using the resistors...

[Anonymous]

Geeze Buckeye its tomorrow now and I don't see that next scintillating engineering lesson here as you promised. DARN!!

Jerry, THANKS for the neat "dynamic braking trick" with the resistor. I'll try it when I kluge up this 16 foot test grade.

Bro. McClellan... MUCH thanks for the link to the earlier grade discussion. Lots of good stuff out there!! Helps when someone who knows where it is steers you to it.

When I was railfanning the Alaskan RR back in '99 I discovered the "Nenanah Loop" which the ARR built just to get from river bank grade up to river crossing bridge grade on the Tanana River near the Town of Nenanah. Guess we'll do something like that, climbing at nearer to 4 % thru an intermediate level between our 15 1/2 inch bench and our floor level flat yards.
By keeping it only ten feet long, "the skinny guy" will still be able to get past the end of it to do 0-5-0 work on the hideout tracks if need be.

But I'm still going to do some experimenting with a full sixteen foot plank between two levels just to see what these trains CAN do. Will report on that when done.

Thanks again all,
Joe

[Anonymous]

Okay guys, here is the report I promised when you helped so much back on November 1st.

We actually ran a fifteen foot rise from floor to a 15.5 inch bench, and then around a bend onto the flat where we laid (temporarily) enough track to hold an entire consist.

Rails were Gargraves Phantom with steel (NOT STAINLESS) rails.

We applied transformer power in four separate places to keep the voltage reasonably uniform.
Always had more than enough power, it was the TRACTION that failed in every case. No wonder the 1:1 Loco designers put WEIGHT over those drivers.

Twelve different engines climbed it running light. Even the little switchers, some with rubber tires and a couple with magnetraction.

Then we started adding steel framed double stack COFC cars as they are the heaviest rolling stock we own.

The little switchers could only haul one up that grade and one of those lost traction just before the crest. No small, comparatively light engine would draw more than to up there.

The heavyweights like the 681 and 682 (both 6-8-6) hauled three but lost traction with four.

The modern GG1 with rubber tires hauled three but spun with four just before the crest. With a "notch 8" running start that engine made it with four and almost crested with five.

The FM hauled four barely and spun at mid slope with 5 cars.

We dropped the table to half that height resulting in a 4.25 percent grade and all mainline HEP hauled the full consist of 8 cars though they needed a lot of throttle going into the climb.

The Switchers doubled their drag and one actually hauled three up and over.

Tacked on a "helper" and WOW, guess the 1:1 scale guys really DID know something. Even a little 44 tonner gave enough help for the SW-2 types to haul five cars up and over.

If anyone wants to model a real HILL where helpers are used and bring them in down at the tail end of the consist from a siding, it WILL work. At least with heavy cars. Perhaps an accordion problem with light weights though we did not try that.
I'd love to work such a HILL into the LR&H but in an attic, height forces you IN really fast due to roof slope.

CONCLUSION!! 4.25% IS THE GREATEST PRACTICAL GRADE FOR TIN-PLATE MODEL RAILROADS.
(A coupla guys out there can now say "I told him so"...and they DID too)

FOR THE GEOMETRY-CHALLENGED THAT WORKS OUT TO ABOUT A HALF INCH OF RISE PER FOOT OF RUN.

Just tape a 2 inch spacer to the end of your 4 foot level and you've got your "maximum rise guage"..

Hope the foregoing is useful to somebody. It was fun doing the experimenting. Now, the "not so much fun" part is fitting the helix and long oval loop in under the planned benchwork. THAT already prompted a posting today about squeezing the radius.

Still Building Our Dream and having as much fun doing it as we used to have running the LR&H 25 years ago. "Auntie CATHY", the other LR&H Engineer from back then is coming for two weeks at Christmas.. She's gonna LOVE it.

My cup runneth over!

Joe

[Anonymous]

QUOTE: Originally posted by lionelsoni

For the set-out problem, how about a trailing-point switch down the hill below the train, leading not to a siding but immediately to a bumper?

Or a trailing-point switch just below the siding, with a substantial chock soldered onto the inside diverging rail far enough downhill from the points so as not to interfere with the sideframes of rolling stock on the main line. The front truck of the front car would move sideways, but only about half an inch, to reach the chock. You could cut away most of the rest of the switch, if you like, or make it look like a disused siding.

Gee Lionlelson I LIKE that. In fact I like BOTH ideas but the SUBSTANTIAL chock will surely be needed or a heavy consist will pu***he last car (usually a lightweight crummy) right over it. The out-of-service siding with a bumper is a real winner though. Crummy comes up agains bumper, break train, scoot off with set-out, do pick up and return to find remainder of consist right where you left it on the hill. WINNER!!

It may well be so on the LR&H. If so I'll take a pic and send it to you.

Thanks again,
Joe

[wrmcclellan]

Joe,

I (for one) and I am sure many others really appreciate your group's followup on this subject. I also think others will appreciate your reducing the requirements (2 inches for every 4 feet) into something more understandable for many who watch the forum.

Nice work on your part! Thanks for taking the time. Also sounds like you had fun too!

Thanks!
Roy

[daan]

With an 8.6% grade you could have made a rocket launcher..

[Anonymous]

QUOTE: Originally posted by wrmcclellan

Joe,

I (for one) and I am sure many others really appreciate your group's followup on this subject. I also think others will appreciate your reducing the requirements (2 inches for every 4 feet) into something more understandable for many who watch the forum.

Nice work on your part! Thanks for taking the time. Also sounds like you had fun too!

Thanks!
Roy

Thanks for the kind words Roy.
It WAS fun and I hope somewhere someone building a layout benefits from it. Re: The handy spacer and level trick.
I learned it laying sewer pipes before laser levels came along. To keep the pipe running down at a quarter inch to the foot we'd just tape a piece of 1 inch board on the bottom of our four foot bubble stick. When we'e tamped and shimmed so the level read level, the desired pitch was obtained and on to the next length.

WARNING!! Buckeye Riveter pointed out that there is a REDUCTION IN TRACTION ON A CURVE!!

Dang smart engineer types are always pointing out the hidden flaw AFTER I'm feeling so smart and pleased with myself. They did it for a lifetime in the construction biz and now they're doing in my retirement hobby... Next life I think I'll just go off to college and BE one of them!! I've still got a slip stick somewhere around here.

I did all that testing on a straight plank. But on an 054 helix we may find the lost traction enough to force us into a "helper" engine situation or making that "lighter tonnage territory"...

Once again Roy, sincere thanks for the kind words. Eveyone on this forum is so darn helpful I'd be pleased to think I helped a bit too.

Joe