Bending Rails vertically.

[Anonymous]

I have a rail bender and I do bend rails horizontally all the time but in my area 3 I need to put a gentle dip in a 3.7 m (12') length of track.

Has anyone done it and how did you do it?


Rgs ian

[Big_Boy_4005]

Obviously, the one thing you don't want to do is kink the rails.

Make a curved jig, about 1 meter long, and about 5cm high at the center. Secure one end of the rail, and wrap the loose end around the curve. It will not want to stay bent that sharply. Repeat this process until you have the amount of curve you want. You may need to take a block of wood and tap it gently with a hammer to get more bend in the rail if you can't get the desired amount bending by hand.

At the bottom of the dip,you'll be placing the head of the rail against the curve of the jig. Don't get it too sharp. Cow catchers will start bottoming out on the ties if there is not enough transition.

[toenailridgesl]

Ian,
wouldn't it be easier to do what the prototype did and bridge or landfill the low area so that you don't have transitions in grade?

[Big_Boy_4005]

QUOTE: Originally posted by toenailridgesl

Ian,
wouldn't it be easier to do what the prototype did and bridge or landfill the low area so that you don't have transitions in grade?

I almost suggested that too Phil. There is one reason, that I can think of, why Ian couldn't do that. That would be if he was trying to get this track under a bridge, and needed the head clearance. You are right, a vertical curve is not desirable if it can be avoided.

[toenailridgesl]

G'day Elliot. Had a good Xmas in Brainerd up your way many years ago, but COLD!!!!
I still reckon that any grade that needs the rail bent vertically is too steep. LargeScale trains really have a practical limit of 4% grade so to get eg. a one foot clearance under a bridge you'd have a max 4% grade into and out of the lowest point. 4% translates to 1ft every 25ft of line and the rail doesn't need bending vertically for such a gentle transition. It has sufficient flexibility inherent over that length to sag all by itself.
If the trackplan requires more than 4%, it might be time to rethink the trackplan, or use an helix or switchback.

[Big_Boy_4005]

Phil, it may be day where you and Ian are, but it's midnight here.[;)] It seems so srtange to think that you guys have Christmas during the summer. Does it even get that cold anywhere in Australia.

4% is pretty typical as the practical maximum grade for real trains, and model trains of all scales. 2% is much better.

I'm as curious as you, as to why Ian thinks he needs to bend the rail. I do 3 rail O indoors, but the rules are pretty much the same. I don't bend the rails when I need to make a vertical transition, I curve the roadbed gently up or down, and fasten the track to it. The rail simply conforms to the shape of the roadbed.

Another possibility is that Ian is hand laying the rails to the individual ties. If he has the ties down, it may be easier to spike if the rail is pre shaped.

I've never actually worked outdoors, though I once gave it very serious consideration. I even subscribed to GR for a few years. I have an old Lionel large scale set that comes out for Christmas sometimes.[8D]

[Anonymous]

Hi Ian,
Gravity, works wonders. I laid some track onto gravel 2 weekends ago and didn't ballast it level, within a couple of days it followed the contour of the gravel. I have one gentle incline (at the moment) and the track follows the ballast, I use my Aristo snow plough to check the grade and if that clears it everything else will. If you are gaining height for a bridge over other track an 8' diameter circle of track is 25.13', 10' is 31.41'.
Happy track laying.
Cheers,
Kim
[tup]