Materials used to make rails/trains?

Question

what type of materials (preferably polymer) are used to make rails/trains besides steel or iron?

can someone help me pleeeasssseee..

u will be deeply appreciated. (:

Answer 1

Hehe, well above is a mighty complicated answer.  Try this: Steel works really well, and it's cheap :)  

Weight is not a big issue on trains, so the considerable cost of composites (or even aluminum) makes no sense.  

Steel stands up well to vibration.  It's easy to repair.  When it fails, it fails slowly and gives lots of early warning that can be caught on inspection - unlike other materials that just snap. Steel is a well-known quantity in railroading.

Now, you are seeing composites in some cases.  Plastic railroad ties have a huge future because they don't rot (unlike wood) and they are survive vibration and abuse (unlike concrete). The nonconductive aspects of plastics and composites are also useful in electric railways, for instance as catenary hangers or third rail coverboards.

Answer 2

You won't find much in the way of polymers in rails or trains, because of what's called "telescoping."  When trains were first invented, they used wooden construction, and in many cases rails were pieces of wood with an iron strip across the top.  The rail has to be metal of some type, so that friction is kept to a minimum - you want the rail cars to roll as easily as possible (unfortunately, that means the engine won't get good traction either - the way they got around that was to make it insanely heavy).

Anyway, they noticed that, when two trains crashed together, or a train crashed into something stationary, that the cars would basically collapse inward, like a telescope being pushed closed.  This would of course kill all the passengers, so the government mandated that the rail cars be built to withstand enormous force from either end, so that in the event of a crash, the car wouldn't collapse.  This made the rail car very heavy, so they had to go with all-steel track to support the weight.  This is why, when you see a train crash (rare), the cars are not crushed, but piled up with their shapes relatively intact, like a stack of wood.

For innercity rail, like trolleys, they are constructed much lighter since they will not share a track with loaded freight trains, and crashes are likely to be far less violent.  Commuter trains, on the other hand, have to be contructed very stoutly, which is why your radio doesn't work well on a train - too much metal.

If you want to use composites on a train, you can.  You just have to make sure that the resulting design will pass the federal standards for rail car construction. If the design can withstand the forces involved, then it's fine.  It seems that they haven't yet been able to devise a composite car that's strong enough and still cheaper than steel, so all-steel is what we have today.

Answer 3

For rails, well the only material used to my knowledge is steel - it works and has stood the test of time.

For trains, mainly extruded aluminium these days, or fibreglass for body mouldings, pressed steel used to be common, before that was wood. No polymers as yet.