I have personally put railroad down at a steel plant in the midwest. All we did to make it curve is push it in the direction we needed it to go with a tractor then spike it down. The other rail was then set and forced into place while maintaining the proper guage or distance and spiked down too. No heat used at all.
One way to get pretty accurate curves is to draw each rail on a piece of paper to the desired radius. You can do this using strings of the correct length with loops at either end. Stick a tack into the floor through one loop and use the other to trap the point of a pencil to draw the curve. Bending the rail to match the drawn lines should be a relatively easy task. Fine adjustments can be done by hand. Rails needn't be perfectly bent--the ties will hold them to gauge. If you are building your railroad indoors, you might get away with bending already-assembled track, but I wouldn't recommend it. Outdoors, it's a definite no-no. The track will always try to unbend and with sun, weather, and frost heave aiding and abetting it, it will eventually succeed.
I am visulaizing, They have a special carving machine wich first kinds of burns it to make it melt, Somehow made out of charcoal or metal.
Simply,We all know its made from the factory but your main point is "How"
There are special types of patterns, And a railroad track is known as very dificult to make. It needs to stay strong on a soft surface, So the train can come and go easily without any accidents. If a nut or bolt is not pushed in propally, Then that is what causes the train to stop. Like Learning To Learn said, There are special panks of wood wich don't get made with the track. They are actually inserted first, And there for, The raildroad rails can be inserted on.
Some are heated and bent into shape, some are bent right at the scene, knew some guys that did this for the rail road companies etc...the best to you
Carbon Dioxide lasers! Lasers play an instrumental role in the in the production of such products. Just like with heat, they heat the track and bend it using a pipe - bender - e.g
I think they first take the angle of the curve , then measurements are send to the factory ,
heard that they use some kind of rail bender machine which bends the heated rails and it can bend rails up to 180* or something like that
The are heated up so they can bend because every thing has a melting point
The have it super heated then bend it with giant clamps. Then the cool it down. You are left witha strong bent piece of metal.
I'm going with formed at the foundry while still hot from the forge/extruder when ordered for a repair/replacement. Then shipped to the site for placement.this is my guess.
Heat! They heat up the iron then they bend it with a mechanism like a pipe bender.