When laying continuous rails on railroad track beds, how do they bend the rails to follow the curves?

Question

When laying continuous rails on railroad track beds, how do they bend the rails to follow the curves?

Answer 1

Well, if needed the rail is heated but typically, with CWR, cut in sections of a 1/4-mile, such lengths allow the rail to be very pliable and easy to maneuver into whatever shape the track/MOW crew desires (with the help of heavy machinery, of course).

Answer 2

As others point out... it DOES have some inherent "flex" over it's length.  I like the example of a 2x4 of 20 or 40 feet in length.

I have seen them lay it out on new concrete ties, clamp it down, and then run the ballast-shaker / leveller make everything smooth and beautiful.

Answer 3

Good question, shows some insight and thought.

The curves, as stated above are not so tight that the rail needs to be "bent" as much as just flexed. It is surprising to see how much steel rail flexes as it comes off of "ribbon rail" trains.

And for Hoghead, you are right about jointed rail in new track but I have also seen CWR layed down in new construction, ballast, then ties, then the rail and the surfacing gang.

Answer 4

They bend easily, relatively speaking. They are usually layed on the ground next to the road bed. A catapillar with a custom designed tong-like graple then lifts a portion of the rail on to the ties. Maybe 40 feet at a time.Then it is spiked down. The rail isn't as flexible as a garden hose. Maybe more like a 1 by 4 inch length of wood that's 20 feet long. If you were to pick up that 1 by 4 in the middle, the ends would sag down. If you were strong enough to pick up a rail of the same length, it would be about that flexible I think.

Answer 5

Ribbon rail isn't used for initial construction.  The road bed is built in the conventional method using good ol' jointed rail.

Ribbon rail is installed after wards, and after the new roadbed had "consolidated", an engineering term for the ballast having settled and the structure firmed up.

A train designed for the purpose distributes the 1320' sections of rail along the route.  The steel gangs then come in to swap out the rail.  As pointed out above, the stuff really is very flexible.  Machines called "speed swings" pick up the rail and lay it into the tie plates where the previous rail had been.

Welders then come in and weld the joints to form a continuous, welded rail.

A work train then comes in and picks up the rail used in construction, and the job is done.