steep gradient

[scroggin]

I were thinking of putting in a 6% gradient on a hidden section of track for downhill running only. Has anyone ever done this? and would it cause any problems such as derailments at the front of a long train ? I use kadee couplers.

 

[Y3a]

Some steam engines may buck a little and cause a derailment if on curved track.

 

[Rico]

You'd have to keep heavier cars to the front of the train.
I've stopped long coal trains on the club's old layout and had major derailments on the curve.

 

[otiscnj]

Is it a straight shot, or are there any curves? Also I'd start and end the grade with sections of less steep running. This will avoid cars getting uncoupled, or being bottomed out, like hoppers, or depressed center flats.

My second layout had 7% grades, and one started on a curve, some engines and cars didn't like that. The other ended with a curve, and I had a lot of derailments at the bottom.

 

[PApat]

Just for the record - the current issue of "Trains" magazine has a US map from the 1950's and shows all major lines and the highest elevation and the steepest grade. The steepest grade in all of the US was DRGW at 4%. Most railroads are just below 2%.

I know your question was not about prototype, but thought it might be helpful as you consider what you are planning.

 

[kjd]

Just for the record - the current issue of "Trains" magazine has a US map from the 1950's and shows all major lines and the highest elevation and the steepest grade. The steepest grade in all of the US was DRGW at 4%. Most railroads are just below 2%.

I know your question was not about prototype, but thought it might be helpful as you consider what you are planning.

NS's Saluda maxed out at 5.1%. Logging lines were, of course, much steeper than that.
http://en.wikipedia.org/wiki/Saluda_Grade


As far as the model, I'd try to lessen the grade or keep it straight for one train length past the bottom. Maybe do some tests first.

 

[scroggin]

Hey thanks for your advice everyone just what I needed to know. sounds like that Idea is a no-go.
Just on the topic of prototype grades here is a tiny youtube clip of our steepest gradient http://www.youtube.com/watch?v=S2VkAO9G_LY it was a 3 mile section of 6.5% track that was operated on by fell locomotives they were 39 ton tank engines which had wheels underneath that clamped either side of a centre rail. They could tow a maximum of 65 tons each up that grade at speeds of 4-6 MPH. Some of our ordinary tank engines had enough traction to get up that grade on dry rails.
Going down that grade with a 250 ton train they would put the engines at the front followed by two fell brake vans they would have a brake van in the middle of the train and two at the rear the brake pads were a block of steel about 2"x2"x14" which clamped either side of the centre rail they had to be replace every trip because the would only measure 2"x1" at the bottom. There was never a runaway train on that grade

 

[scroggin]

here is a clip of the deniston incline where full size New Zealand Rail coal wagons were lowered down a 1 in 1.25 gradient http://www.youtube.com/watch?v=1cCwscH8_9s

 

[clifwst]

Just for informational purposes, Madison Indiana has the steepest grade ever used on a class one RR, 5.89%.

the Madison and Indianapolis Railroad incline that connects the hilltop area to the old city. Completed in 1841, the Madison incline of 7,012 feet was - and remains today - the steepest grade of any line-haul railroad in the country. The incline ascends 413 feet, or 311 feet per mile, giving the tracks a 5.89 percent grade.

Madison Indiana was at the end of a Pennsllvania RR Branch line, which is currently owned and operated by the The City of Madison Port Authority Railroad as needed.

Video of RR but not of the grade itself;

http://www.youtube.com/watch?v=Aryb_qi1Yss&feature=related

So yes to the original poster such a grade is possible, the PRR operated the grade with 2 SD9's with dynamic brakes.

This link is to one of the steam locomotives constructed to operate the grade.

http://mjcpl.org/rivertorail/buildingtherailroad/the-reuben-wells-locomotive