GRADES & BRAKES

[Anonymous]

To make our multi-level concept work (and the "hideouts" accessable to the "skinny guy") we find we need our mainline to climb 15.5 inches over 15 linear feet. Thats 8.6 %

Head end power ranges from early magnetraction thru MPC rubber tires to modern Williams etc. Consist limits will be ten feet except for our long-haul heavyweights which total 15 feet when a Presidential campaign car is tacked on.
Our steel frame inter-modal cars are pretty heavy as are some of our unit trains (coal etc).

ARE WE HEADED FOR TROUBLE, TRACTION OR OTHERWISE?

Will a switched electromagnet serve as a "rolling stock brake" on that grade for up to four cars and a cab while the head end does a set-out? Aybody have a "spec" for such an electromagnet?? Or a better way to "set the brakes" before uncoupling the head end power and cars to be set out?

If nobody has done this sort of thing or the requisite testing, we'll pause while I power up that stretch and do some experiments. Just trying to save time and not "re-invent the wheel".

Thanks to all, especially YOU Big-boy.

Joe

[Big_Boy_4005]

Yikes Joe!!! 8.6% is a killer grade, the first step is realizing that you have a problem. Congratulations there.

So, you want to double the hill? My suggestion, short of rethinking the situation, would be to have some kind of physical stop. A magnet won't be strong enough.

How about using a switch machine to raise and lower a metal hook between the rails. You could have it pop up and catch the last axle, holding the train in position. I was thinking of using something like that as a stop at the far end of a hump yard.

[railman]

Holy shamoley...that's a grade. BB4005's ideas sound workable.

[Big_Boy_4005]

Yeah Ron, Joe and I go back a ways now. He knew I would find this question, and I did not disappoint.

Hey Joe, ever considered a cog railway for that grade? How about a cable car arrangement? 8.6% is actually realistic for those types of systems.[swg]

[Anonymous]

Hello Joe,

15.5 up and 180 across gives an 11.6% grade....Serious rethinking is required. Can you say funicular? I have one section at 2.5% and few trains can make it with a solo locomotive.

[Big_Boy_4005]

Gee Tony, I didn't stop to do the math. I just took Joe's word for it, but you are correct, 11.6%!!!!

Joe, maybe we do need to rethink this entire climb. The actual climb is going to be even steeper, as you need to have vertical transitions at the top and bottom. Can I sell you on a helix or a trip around the room? That's how we are going to get the grade down.

[Anonymous]

Once Again, THANKS GUYS!!

I suspected we might be heading for trouble and figured one or more of you must have a good idea about just how many times prototype we could get away with.

There is only fifteen feet from end of yards to end of room. We wanted that fifteen and a half inch difference so "the skinny guy" could reach the hideout tracks in case 0-5-0 re-railing or other help might be needed under there.

Guess we'll have to go to slightly over Road Clearance and re-route the hide-outs to near the front of the bench so he can just reach under.

That will make the climb about 8 inches over fifteen feet or .044. 4.4 % is still a lot according to the experience shared from Vancouver (thanks Tony). If that still won't work we'll have to either carry the climb into the next room or around the corner and across the first room. That however will mess up our planned interchanges. ARRrrrggghhhh!!! Oh well better re-planning than having to tear up something that disappoints.

B-T-W Tony et. al. I know there are differences in units of measurement between the two great North American nations. But I think percentage of grade is still arrived at by dividing the rise by the length once you have a common unit (inches, feet etc.)

15 1/2 does indeed go into 180 eleven point six times. But 11.6 is only 8.4111 PERCENT of 180 which in this case is our "hundred percent value"..

THANKS Elliott for the "brake" idea. It sounds great!! I've some old Lionel 022 switches and they have a great solenoid in them. I think I'll use one of those to raise and lower the brake pin behind the axles. They have plenty of power and they live forever. They can only stand momentary power but if they dont "lock" in position I'll conjure up something that alternates between "up and locked" and "unlocked & down"

I should have realized that no magnet would grab hard enough.

I'll report the results of that brake design as soon as I've done it. Maybe I'll see it used in your great hump yard. It'll be a great satisfaction to know that I contributed something to the design of THAT layout.

Thaks again all. Back to the drawing boards!!

Joe

[cwclark]

i don't think i'd want to go down a 11% grade either...puts a new meaning on dynamic braking!...and some killer air brakes wouldn't hurt either...

[Big_Boy_4005]

QUOTE: Originally posted by LightBender

Hello Joe,

15.5 up and 180 across gives an 11.6% grade....Serious rethinking is required. Can you say funicular? I have one section at 2.5% and few trains can make it with a solo locomotive.

Tony, actually Joe's grade is 8.6%. The answer is not reached by simple division. The formula is "units of rise per 100 units of run".

15.5 / (180 / 100) = ~8.6 = very steep