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4% incline: was it a waste?

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4% incline: was it a waste?
Posted by kasskaboose on Wednesday, April 11, 2018 9:33 PM

Some say that 4% inclines for diesel is too troublesome and unrealistic.  Should I avoid the likely derailments, shorter consists and other issues by ripping up the one inch foam and putting it as background?  The plan is to have the consists climb that incline and remain at that elevation for about 60" before droopping an inch.

Interestingly, I have seen plenty use 4% risers without issues.  Someone here mentioned that diesel tends to do better in inclines than steam (I have the former).  For grins, I put a diesel on the incline with a few cars and they didn't roll back or decouple.  That gives me some hope that I can keep the current arrangement.

Did I waste all that time and money?

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Posted by RR_Mel on Wednesday, April 11, 2018 10:25 PM

I have two HO 3½% grades, one is a normal curved 32” radius to straight to curved 30” the other is a 32” radius helix.  Never had any problems with either steam or diesel.
 
 
 
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Posted by SpaceMouse on Wednesday, April 11, 2018 10:27 PM

I planned to do a 4% grade, then I found that the grade is compounded with curves which have increased drag (friction). My 4% grade with curves calculated out to 6.6%. I was using steam, and only my geared steam could make the climb and only one could pull 6 cars. 

So my suggestion is to test it before you decide. I got an 8 foot 2x4 screwed down some track, hooked it to my power, and raised one end 6 1/2 inched for the test. Hopefully someone will post the formula for determining the calculated grade for any curves you have.

As a result of my testing I reduced my grade to 3%. You can spread your risers out to make a 3% grade if needed.

Chip

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Posted by hon30critter on Wednesday, April 11, 2018 10:45 PM

I would be more concerned about the length of the vertical transitions than the grade. There is a formula to determine the length of vertical easements. Here is a previous thread on the topic:

http://cs.trains.com/mrr/f/11/t/266729.aspx

Dave

 

 

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Posted by gmpullman on Wednesday, April 11, 2018 11:47 PM

kasskaboose
Some say that 4% inclines for diesel is too troublesome and unrealistic.

The PRR ran the Madison (Indiana) grade possibly into the Conrail era. It was 5.89%!

A pair of specially fitted SD-7s were used on the grade, 8588 and 8589. Equipped with special rail washers. Trains were limited to fifteen cars and the locomotive had to be on the down-hill side.

Old history here:

https://tinyurl.com/y9s5t2py

Good Luck, Ed

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Posted by maxman on Thursday, April 12, 2018 12:03 AM

Why do you need a 4% incline in the first place?

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Posted by Southgate on Thursday, April 12, 2018 12:03 AM

I'd suggest you run test trains to see if they'll behave as you want them to on the grade. I had a 4% on my layout. Going up grade was fine, but coming down caused problems. The cars would slack-and-bunch, slack-and-bunch, all the way down. (I believe the specific cars I was running may well have contributed to this as well.) I was running at low speeds. I decided to make that grade into a vehicle road, as the surrounding features allowed it. Looks great that way too.

Some locomotives also had issues with the weight of the train pushing on the gears and actually causing an unwanted eratic braking effect, also when coming down grade. Do enough testing at the speeds you'll be operating at, and with locomotives and train cars you expect to run on it to prove if will work before making it permanent. Dan

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Posted by riogrande5761 on Thursday, April 12, 2018 7:03 AM

Personally I'd rather stick with grades under 3% but I prefer to run longer trains. If you plan to run shorter trains then you may be ok.  Just like in real life, a 4% grade in HO will be somewhat restrictive, but in modeling we often have to make those kinds of limiting choices.

Rio Grande.  The Action Road

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Posted by rrinker on Thursday, April 12, 2018 7:16 AM

maxman

Why do you need a 4% incline in the first place?

 

 If you only have a 4x8 and want one track to go over another, you don't have much choice.

                              --Randy

 


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Posted by rrinker on Thursday, April 12, 2018 7:18 AM

gmpullman

 

 
kasskaboose
Some say that 4% inclines for diesel is too troublesome and unrealistic.

 

The PRR ran the Madison (Indiana) grade possibly into the Conrail era. It was 5.89%!

A pair of specially fitted SD-7s were used on the grade, 8588 and 8589. Equipped with special rail washers. Trains were limited to fifteen cars and the locomotive had to be on the down-hill side.

Old history here:

https://tinyurl.com/y9s5t2py

Good Luck, Ed

 

 Of course, they once sent one of those locos to the shop and the shop crew had no idea what all the extra brake gear was for so they never hooked it up. The first crew to ride that loco down had a rather scary surprise. It was a story in Trains or Classic Trains.

                              --Randy

 


Modeling the Reading Railroad in the 1950's

 

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Posted by maxman on Thursday, April 12, 2018 8:23 AM

I didn't see anything about 4 X 8.  So the question still stands.

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Posted by Water Level Route on Thursday, April 12, 2018 8:39 AM

maxman

I didn't see anything about 4 X 8.  So the question still stands.

 

His plan probably requires it for some reason or another.  

I have a curving (~25" radius) 3-1/2% grade on my layout.  I run trains of roughly 8 cars plus caboose pulled by medium steam and early diesels.  It's pretty much the limit of what my Bachmann 4-8-2 can pull up the hill.  My Broadway 2-8-2's (have traction tires) or my Proto F-3's, however, can handle plenty more.  I have tested that.  It's a compromise I had to make and am happy I did.  Mock it up with your intended consist and give it a shot.  You might be pleasantly surprised.

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Posted by swisstrain on Thursday, April 12, 2018 8:57 AM

As others propose, I think running some trials with the actual equipment that you are planning to run makes the most sense.

Personally, I started building a layout that had 2.5% grades, compounded with 18" radius curves, and that proved too much for my steam engines (4-4-0 and 2-6-0) to run consistently.  I found that I can run up 1.8% with reasonble length consists of about 5-6 cars.  Per a calculation that originates by John Allen, you can calculate the additional drag in curves as 32/r, in my case 18", which results in a coefficient of 1.78, which then should be added as a percentage to the actual incline. This means  that my incline in those curves is equivalent to roughly 3.6%.  You should definitely consider assessing that aspect (from your post I do not see if you are in fact running a curve).

The second aspect someone mentioned is the length of transition, since abruptly going from 4% to flat would definitely cause unwanted uncouplings.  E.g. before and after the actual inclines you are running, you would need to transition with lower inclines, making either the 4% even steeper in between, or would not get you to the height that you actually want to achieve (do you really need that height?).

Good luck with your construction.

Urs

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Posted by carl425 on Thursday, April 12, 2018 9:54 AM

kasskaboose
Did I waste all that time and money?

First off, this is a hobby, not a 401k.  You need to look at all the money you put into the hobby, even on stuff you tear out, as money that was spent on entertainment.

Second, there no absolutes, no one size fits all.  Everything is a tradeoff.  You've already built it, it would be silly to tear it down before testing it.

FWIW, with an Athearn HO RTR SD45 I pulled 18 BLI 70-ton hoppers (granted, not very heavy cars) up a 5% grade.  It is my opinion that a lot of these "rules" are rooted in old experiences with old equipment.

I have the right to remain silent.  By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.

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Posted by davidmurray on Thursday, April 12, 2018 11:38 AM

I used Woodland Scienics 4% inclines to go up 2 inches, short "Y" and switch back on the level, then up two more inches to an iron ore mine.  !4 years later no derailments, no percieved engine damage.

The trains are short, as it is a one stop switching branch, but it works, with no deliberate transitions, with ore cars, or box cars or gondola.

Dave

 

David Murray from Oshawa, Ontario Canada
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Posted by maxman on Thursday, April 12, 2018 4:51 PM

Water Level Route
maxman I didn't see anything about 4 X 8. So the question still stands.

His plan probably requires it for some reason or another.

Yes, but what reason?  Is this a logging railroad, or a class 1?

A figure 8 over and under?

There may be alternatives to a 4% grade.  For example if it is a figure 8 the over track can have a 2% up grade and the under track can have a 2% down grade.  The separaton at the crossing point will be the same.

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Posted by kasskaboose on Thursday, April 12, 2018 7:24 PM

Carl: You're right about it not being a 401K but I hate wasting money.  Hard to enjoy when have three young kids.  They want to see the layout and I want to show them but trying to ensure it all looks ok.

I decied to not take chances and remove the 1" foam.  The foam can get used elsewhere.  While fun to have such an elevation change, I think the chances of potential issues out-weigh the enjoyment or desire to test the laws of physics.  Thanks all for your help!

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Posted by Bob grech on Friday, April 13, 2018 12:19 PM

maxman

 

 I 100% agree with the comment made by Maxman. A good method many use when working with small layouts (4 by 8) is to split the difference. 2% up 2% down. That is why it's never a good idea to plan a layout around a flat table top unless you are modeling a yard or urban scene not requiring the need for grades. You simply set your zero elavation point at 2 inches or higher above the top of your surrounding bench work using risers. If working with the newer foam products such a woodland scenics, they make both a 2 or 4 inch (flat) riser that can be used to set your zero elavation track work, you then would lower or rise from that point using the 2% incline (up or down) to achive the desired separation. This is done by placing the inclince piece on top of the flat riser to go up, or just the incline in reverse to go down.
Water Level Route
maxman I didn't see anything about 4 X 8. So the question still stands.

His plan probably requires it for some reason or another.

 

Yes, but what reason?  Is this a logging railroad, or a class 1?

A figure 8 over and under?

There may be alternatives to a 4% grade.  For example if it is a figure 8 the over track can have a 2% up grade and the under track can have a 2% down grade.  The separaton at the crossing point will be the same.

 

Have Fun.... Bob.

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Posted by gregc on Friday, April 13, 2018 12:42 PM

maxman
There may be alternatives to a 4% grade.  For example if it is a figure 8 the over track can have a 2% up grade and the under track can have a 2% down grade.  The separaton at the crossing point will be the same.

huh?

greg - Philadelphia & Reading / Reading

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Posted by maxman on Friday, April 13, 2018 1:19 PM

gregc

 maxman

There may be alternatives to a 4% grade.  For example if it is a figure 8 the over track can have a 2% up grade and the under track can have a 2% down grade.  The separaton at the crossing point will be the same.

 

huh?

 

 
A failure to communicate?  Let's assume that a 4 inch separation is required.  Let's also assume that we have 100 inches of length to get to that separation (not including any transitions at the beginning of the grade).   So that would be a 4% grade.
 
On the other hand, if the track to be crossed can be depressed below grade by 2 inches, then the track crossing over only has to go up 2 inches.  We end up with the same 4 inch separation but the grade for each track is only 2%.
 
The ability to have a track go below grade is one of the advantages of open grid table construction.
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Posted by mbinsewi on Friday, April 13, 2018 1:19 PM

It sounds like it would make sense,

But, if you start at the lowest on the "under" track, go around the loop to the top of the "over" track, wouldn't that total run be a 4% grade?

Or am I missing something. Confused

Mike.

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Posted by gregc on Friday, April 13, 2018 1:49 PM

average grade depends on the difference in height and distance.

maxman
On the other hand, if the track to be crossed can be depressed below grade by 2 inches, then the track crossing over only has to go up 2 inches.  We end up with the same 4 inch separation but the grade for each track is only 2%.

don't see it.   how can you "depress" the one track and still have the "same 4 inch separation"?

 

greg - Philadelphia & Reading / Reading

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Posted by rrinker on Friday, April 13, 2018 2:14 PM

Starting at 0 level, go clockwise on a 2% grade going up. 100 inches later, you are 2" above the 0 point. Back to the starting point, run counter-clockwise for 100 inches, going down at 2%. 100 inches later, you are 2" below the 0 point. Total separation, 4".

If you start at the 0 point and only go up on one side (think your traditional figure 8 pier set), you have to use a 4% grade to get a 4" rise at 100 inches past the 0 point.

One track goes up, the other goes down, each at half the grade. The disadvantage is that neither track has any level space on it, they are both on grades.

                                     --Randy

 


Modeling the Reading Railroad in the 1950's

 

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Posted by rrinker on Friday, April 13, 2018 2:16 PM

mbinsewi

It sounds like it would make sense,

But, if you start at the lowest on the "under" track, go around the loop to the top of the "over" track, wouldn't that total run be a 4% grade?

Or am I missing something. Confused

Mike.

 

No, it would be double the run length at half the grade.

                              --Randy

 


Modeling the Reading Railroad in the 1950's

 

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Posted by mbinsewi on Friday, April 13, 2018 4:00 PM

rrinker
Starting at 0 level, go clockwise on a 2% grade going up. 100 inches later, you are 2" above the 0 point. Back to the starting point, run counter-clockwise for 100 inches, going down at 2%. 100 inches later, you are 2" below the 0 point. Total separation, 4".

But you traveled a total of 200" to get that 4" seperation.  Evidently, the OP doesn't have that much space.

Mike.

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Posted by maxman on Friday, April 13, 2018 4:36 PM

mbinsewi

 rrinker

Starting at 0 level, go clockwise on a 2% grade going up. 100 inches later, you are 2" above the 0 point. Back to the starting point, run counter-clockwise for 100 inches, going down at 2%. 100 inches later, you are 2" below the 0 point. Total separation, 4".

 

But you traveled a total of 200" to get that 4" seperation.  Evidently, the OP doesn't have that much space.

Mike.

 

 
Well, we still don't know how much space is available.  In any case, we need to get away from the idea that we need to start from a flat table.  Think of a subway/elevated train which starts at the elevated station, runs to the surface station, then tunnels underground to that station.  The surface represents your table top.  And for convenience purposes let's assume that the stations are 100 inches apart, and that the elevation difference between stations is 2 inches
 
So the train starts from your surface station and travels to the elevated station on a 2% grade, which means that it has gone up 2 inches.  Another train runs from the surface station to the underground station on a 2% grade, which means that it has gone down 2 inches.  I think you'll agree that the two trains are now 4 inches difference in elevation, but they have each traveled only 100 inches to get there.
 
Now if you wrap the two ends around toward each other you end up with one-half of a figure 8.  At that point the trains will change grades to go in opposite elevation, at a 2% rate, to get back from where they started.
 
Obviously if we are dealing with a logging railroad where the only direction is up, we have a different circumstance.  So again the question, why is a 4% grade required?
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Posted by rrinker on Friday, April 13, 2018 4:36 PM

Think of your basic 'train set' figure 8 - some sets came with that track plan, all 18" radius curves, maybe 2 straight tracks for the center of the 8. Smaller than a 4x8. One part is completely level, the part that goes up and over is the only one that climbs, at a steep grade. If the next sectioon past the lowest pier didn;t stop at the table top and went lower - you'd have this effect. No extra space required. At, as I mentioned, the expense of having ANY track on the level, it would all be on a grade. 

                                            --Randy


Modeling the Reading Railroad in the 1950's

 

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Posted by wjstix on Friday, April 13, 2018 4:52 PM

davidmurray

I used Woodland Scienics 4% inclines to go up 2 inches, short "Y" and switch back on the level, then up two more inches to an iron ore mine.  !4 years later no derailments, no percieved engine damage.

The trains are short, as it is a one stop switching branch, but it works, with no deliberate transitions, with ore cars, or box cars or gondola.

Dave

 

This is referenced a bit in the original post too. I don't think anybody ever said a 4% grade would cause derailments necessarily, or damage engines, or make them slide back down the grade. If your track is well laid it shouldn't be a problem. However, a 4% grade will reduce the number of cars an engine can pull significantly. I seem to recall reading that a 2% grade could reduce an engine's pulling power to like 40% of what it is on level track.

Stix
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Posted by gregc on Friday, April 13, 2018 6:54 PM

maxman
So the train starts from your surface station and travels to the elevated station on a 2% grade, which means that it has gone up 2 inches.  Another train runs from the surface station to the underground station on a 2% grade, which means that it has gone down 2 inches.  I think you'll agree that the two trains are now 4 inches difference in elevation, but they have each traveled only 100 inches to get there.

what's the distance from 1) the surface station to the elevated station and 2) the surface station to the underground station.

 

i assume there is a 4% grade between where the tracks cross over one another or to achieve the desired change in height.

greg - Philadelphia & Reading / Reading

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Posted by rrinker on Friday, April 13, 2018 7:11 PM

 Ok visualize it this way. Surface station sitting at 0" elevation, there are 2 tracks at this station. 100" away are 2 more stations, one 2" avobe the level of the main station, and one 2" below the level of the main station. What's the grade from the main station to the raised one? 2" over 100", 2%. What's the grade going down to the subway station? 2" over 100", 2%. Neither train ever negotiates more than 2%. Now go another 100" down the line, and have station 2 at the 0" level. 2% down from the elevated station, and 2% up from the subway station. Again, neither train has ever negotiated more than a 2% grade, yet in the middle they were 4" apart.

 Stick a balloon loop on either end, connecting the two tracks - a dogboone shape. Run just one train around the now continuous loop layout. It will go up a 2% grade, pass by the elevated station, descend a 2% grade, loop around station 2, descend a 2% grade to the subway station, then climb a 2% grade and loop around station 1. The train has changed elevation by 4" yet has never negotiated a grade more than 2%.

                            --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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