Need Verification On A Grade Problem

Your calculation of 5% grade is correct.

Your Husky level showing a 2.8 degree angle is also correct.

You are using two different units of measure for measuring a grade.

Paul,

 

According to the grade calculator in RR-Track, a 680" run to climb 34" is a 5% grade.  Can you go around twice?

 

Ron

Just to expand  a little on what Flash said.  2.86 degrees is equivalent to 5% grade.

 

Since % grade = rise divided by run, multiplied by 100%, both of your calculations are correct.  (1 inch divided by 20 inch is the same as 34 inch divided by 680 inch, = 0.05, multiply by 100% to get 5%.)

 

The trigonometry is also not terribly difficult to do with nothing more complicated than the Windows calculator in scientific mode.

 

Imagine your grade as a right triangle (2 sides are perpendicular, the rise and run).  The hypotenuse is the actual track run. 

 

For the angle formed by the track with respect to the flat table, the rise would be referred to as the opposite side, the run is referred to as the adjacent side. 

 

The tangent function for this angle is equal to the opposite divided by the adjacent, or 0.05.  (not expressed as a percent, but hopefully that last part is clear enough now that the decimal is not holding anything up).

 

So, Tangent of angle = 0.05.  Plug 0.05 into the calculator (in scientific mode), hit the "Inv" check box and then the "tan" button, the calculator will reply with 2.86 and a bunch more decimal places that are insignificant for our goals.

 

Alternatively, to check your math backwards, enter 2.86 in the calculator (make sure degrees is selected in the radio button below the display), hit the "tan" button, and you will get a number very close to 0.05.

 

It's handy to be able to do this by hand if you may not always have RR Track handy.

 

Pic to show angle vs grade (not to scale, but numbers are correct):

 

 

 

 

-Dave

 

Ok, if the grade is 5% from the start to the finish, and as the train travels up the track, it is only at 2.8% - is my train moving along the track at 2.8% or not ?

Percent rise and degrees angle are two different units of measure.
A grade with a 5% rise = an angle of 2.8 degrees

Thanks Flash,

 

You just rang a bell in my head.  From what you just said, then my test track was not a grade of 4% - it was an angle of 4% which would put the grade in the stratosphere, which means I should have absolutely no problem pulling cars up the 2.8 angle with my 6000 at all.

 

Thanks again Flash.  I never picked up myself on what you just explained.

 

Corvettte (Paul)

Example using a 3 % grade

 

A 3% grade is referring to the slope of line made by the tracks.
the railroad people describe this as the rise to run ratio.
the grade is expressed as a percent which is the ratio times 100%.
you are told that the track line rises 3 feet for every 100 feet of horizontal travel.
this makes the grade equal to 3/100 = .03 * 100% = 3%.
you can use this information to find the angle of elevation.
draw a right triangle and label it ABC.  A is on the left, B is on the top right, C is on the right at the same level as A.
The angle of elevation is angle A.
The vertical distance traveled is BC.
the horizontal distance traveled is AC.
the distance along the track is AB.
AB is the hypotenuse of this triangle.
AC is the side adjacent to angle A.
BC is the side opposite to angle A.
you use the tangent formula to find angle A.
tangent (A) = opposite / adjacent = 3/100 = .03
A is the angle whose tangent is .03
A is equal to 1.718358002 degrees.
That's your angle of elevation.

The 4 degree angle shown by your tool corresponds to roughly a 7% grade, which most would consider way too much.  (Many even consider 5% pushing our luck)

 

-Dave

Dave45681, I agree totally with you that a 4% angle is suspose to be way to much of a grade.  But as the fact is - my 6000 pulled 13 cars up the grade like it was ready for 10 more.  If that's the case, I guess an engine like the 6000 can pull a lot more cars than most other engines without slipping and I will be relegated to using this engine (or any other engine as powerful as it) up to the second level (which will be a 160 sq. ft. hump freight yard).

Charlie, since I now realize that % and angle are two different things (explained to me by Flash), at this point, not to get snippy, but I really don't care what the grade is.

 

On my test track, the 6000 pulled at half throttle so well the 13 cars, I don't think I'll ever have a problem getting up to the second level as long as I don't hook 30 cars up to the 6000.

 

Corvettte

Paul,  you have to ease in and out of the grade which takes away footage from your climb, which actually will increase your grade to 6 or 7%. you really need to find more footage for your grade. as you have it you will have problems.

JohnS,  I don't understand what you are trying to tell me.

 

Please explain in another way.  I'll lost.

 

Paul

Paul

 

What he is saying is that you can't instantly change from flat level track to a 5% grade. The change is too sudden and the front of your locomotive will likely hit the rails in front of it and derail. You need to go gradually, starting with a 1% grade for a foot or two and then a 2% grade for a foot or two and so on. Similarly, at the other end, you will need to gradually reduce your grade from the 5% down to level again at the top. Therefore, the grade at the midpoint of your  680" run will be greater than 5% 

looking at the diagram Paul you will see two grades, one easing into the grade and the other abruptly entering grade.  your trains cannot bend like that and will derail as the front wheels enter the grade. as you can see by using the easement you shorten the actual length of the grade. to maintain your 5% grade you need more track length on the grade itself.

 

Paul,

How about an elevator?? I have in the works a 60 inch long bridge with a maximum lift of 41 inches. It will be built on the same principles of the transfer table I manufacture. I plan/hope to have it at the York Meet. On my layout, (still in design) I will elevate 2 American Flyer/"S" gauge trains from my table layout to a wall layout just above the doors. This is about a 34/36 inch lift. Most of the mechanism will be inside a mountain. The plan is to run the two trains ("S" gauge) onto the bridge in opposite directions! Feel free to email me at daba@chibardun.net. Thanks, Dave B.

tr18, you're right.  I never thought of that.  From what you said, I would need to get the ramp to a height of, say 36" and at the end - ramp it down slowly to the 34" to keep from having too much of a drop to level off at the 34" spot.

 

Thanks for that, Paul

 

Flyin-high, I thought of an elevator, but the cost would be unbelievably prohibitive for one 6' long.

 

Paul

Another thing you need to consider, Paul, is that on your test track your locomotive was pulling in a straight line. However, on your layout, your trains will be going around curves as well effectively adding weight to the train. Also, you will have to be more aware not only of the load your locomotive is pulling but also how it is distributed among the cars of the train. The combination of grades and curves increases the possibility of cars "string-lining". Finally, your locomotive will be drawing more power. Do you have enough to handle this additional demand?

Double Stack,

 

I thought of what you just brought out.

 

First since I will have only 3 curves, I'm going to make them 072 curves.  Also I plan on experimenting with banking them to compensate for the curve.

 

I've read quite a bit about how to place cars in a consist and also to add weight to light cars so that the light cars won't derail in a curve.

 

I plan to experiment with my 6000 going through the 3 banked curves.  Then start adding cars until I think it is too much and then back off a couple cars.

 

Paul

Paul,

My transfer table (16"wide X 26" long) is priced at $770.00 with manual control (eyeball). Add $125.00 for indexing (Dallee indexer) with as many stops as the operator wants. This elevator as I see will be much less. A 6 foot bridge would be about the same as a 5 foot unit. If you would like to talk one on one, email me and I can call at your convenience. Thanks, Dave B.    P.S. I manufacture turntables and test stands for "O" and "S" gauge as well as rewind Am. Flyer motors.

banked curves in O scale are for looks only. they actually hurt if you are trying to not derail. if your train were going fast enough the banks would help, but they don't. if you like the look, go for it.

JohnS,  you're right about banked curved.  I didn't think about what you just mentioned.

Would a very mild bank help at all or should I do no banks and be careful about slowly pulling a consist through the curves.

 

Paul

Just a thought, but rather than have a long straight incline, have you thought about building a switchback instead? These have been used in many parts of the world to climb mountains. It would also add an interesting operating feature to your layout. 

 

Edit: If my calculations are correct, a 3 stage switchback with 12' end stages could climb 34" with around a maximum 3.5% incline. If you have additional wall space, you could easily extend the end stages too.

Paul, actually a bank to the outside of the curve would help. if you like the look use it. you would have to be pulling a long train to have a problem. the switch back idea would look really neat. I have never seen one modeled. a simple elevator could be made of wood and a couple of lead screws for about $100.

A 5% grade is a perfect excuse for a pusher service. A small storage siding should be located so you can get behind the train before the grade. Also take the knuckle off the front coupler of the pusher for easy operation. I use a RailKing 2-8-8-2 with the pilot trucks removed and the front pilot shortened to look like the D&H 0-8-8-0's used on the Belden Hill.

 

"String-lining" and flange friction can be lessened on curves by using counter elevation. But don't try to run high speed passenger trains as counter elevation will increase the chance of derailing.

Hi  zhyachts,

 

I like your ideas.  They will definitely go into effect on my layout.

 

Corvettte (Paul)

On a 5% grade probably nothing is high speed?

 

I do like the pusher idea

Paul

 

Drop counter elevation if you use pushers as they will push at least half your train against the outside rail.

Hi Zhyachts,

 

I've tested my 6000 pulling 13 cars.  I believe it probably could pulled 5 more cars at that angle.  Let's say because of the curves, I cut back to taking up to the second level only 12 cars at a time.  And suppose I bank the 3 curves which are 072 just a little.

 

Now I pull up the grade very slowly. 

 

My question now becomes this - - - is there more or less chances of a derailment - pulling up the grade.

 

Or will the chances of derailment lessen when pushing.

 

Of course, all plastic cars will have to made heavier with some small weights in the ends of them to help keep from them derailing.

 

Boy, I never thought this exercise would become so complicated.  But I enjoying all the input I getting, and I'm learning tons of information I never knew before, and that makes all this extremely valuable.

 

Thanks,  Paul

Wow!!!!!!!!!!!!!!!!!!!  I will go a bit against the grain here.  A 5% grade is WAY too much.  I have 2.5% max on my layout and that is a noticeable grade that challenges good locos - they can handle it, but barely.  3% is possible maybe.  5% is just - well, too much.  Way too much.  Just my opinion and for what it is worth.

Lee, I agree with you, but as I stated earlier, in my tests on a 20 foot run of track jacked up to 4% grade, the Lionel Santa Fe AC6000 Diesel pulled 13 cars and I thought it would fly off the end and never spun a wheel.  I know it could have pulled at least another 5 or 6 cars. 

 

Of course, I've been told that was a straight shot, not with 072 curves (which I will have 3 of).  The question now is not whether the 6000 can pull that many cars up, but can it pull them around an 072 curve.

Paul, don't forget easing in and out increases the grade as it eats up the distance you are using to calculate your grade. if you come up with 4% now it will end up being over 5 or 6%.

Paul, I am using the Lionel plastic graduated trestle set on one of my loops. This I believe is a 5% grade. !/2" every 10". My grandkids typically run 10 to 15 car trains on this loop of O31 Gauge. Only one small locomotive failed to pull the load up the grade. Wheels spun. More typical of the average midsized locomotive is they have to "DRIVE" the train up and down the grades. (Drive - Either add or decrease power.) The larger Legacy type just take the grades in stride. The picture is of 'Brasseur Electric Trains' layout in Saginaw, MI. which I sorta copied. Hope this helps.

Denny

I understand the loco will pull a train up the grade.  I still will recommend against it if you have other options.   Not all locos you will ever want to run will pull that well, and a 5% grade looks strange.  Also, if you do not ease in and out of the grade with a gradual change in angle of the slop, some longer wheelbase steamers will have fits on that track. 

 

I had a 5% grade on my layout for a while but it was hidden so the esthetics were not an issue.  It was a ramp down to a storage yard built below the benchtop. locos went into a tunnel and under the layout and then to a series of switched storage tracks.  Most locos would do well but not all and I eventually just stopped using it routinely.  It's still there, I guess, but I haven't used it in ages.  

Paul

 

Well, we often have to go with we got. 13 car single engine freights slowly going up a 5 % grade will not string line on 72" curves. Best have lots of traction tires in stock. A 26 car train might and this is where your pusher service comes into play.  Personally I think 5% and pushers is going to provide some fun railroading.

Software is nice to aid in visualizing your project-Here is 630 inches around a 25' x 10' rectangle rising from 0" to 34". 072 curves. It's a 5.2% grade.

 

 

Of course, if you went around twice it would be only a 2.5% grade.

 

I have a couple of long (25 foot) inclines that include curves, I reduce the slop slightly in curves about one third since they are already a bit more of a challenge to a loco's traction.  Seems to get me more even speeds during a climb

Lee, I never thought about that.  I will definitely incorporate that idea into my curves.

 

Corvettte (Paul)

'ere ya go, mate!!  Why, were almost there...a room-sized helix!!

 

I don't like the idea of going around twice.  Then you have track up in the air in front of the layout blocking the view of stuff on the table.  I've already thought of that.  In fact I had written out diagrams of just that and didn't like it.

 

Paul