Why is it there's stones along at the railway tracks?

Question

Why is it there's stones along at the railway tracks?

Answer 1

This question is constantly asked on this forum. It is called ballast and forms the foundation of the railway track. Just as a road for cars could not be built by laying the tarmac or concrete on the bare soil, neither can a railway be built by laying the rails and sleepers (ties) directly on to the ground. Is is required to provide a firm surface - without ballast you would have a very bumpy ride indeed (and probably a short one as the train would be quickly derailed as the rails would spread)

Answer 2

Yup, I cant add much to what is there about the ballast beingnecessary to hold the track where it belongs.

I have worked on very old branchlines where the ballast was esentially gone and the track was ballasted with sod, doesnt work very good, the ties rot very fast and there is constant fire danger in late summer from sparks.

Rocks rule lol.

Answer 3

First off they are there to help prevent eroision and keeping the timbers from being covered with dirt allows them to breath and not stay wet all the time so they don't rot as fast

Answer 4

Hi they are called ballest they support the sleepers and the track to stop the tracks moving, which would result in buckling and eventually a derailment.

Answer 5

So the rails don't sink into the dirt. Trains are quite heavy ya know.

Answer 6

It's called ballast.  It's meant as a foundation.  If you put the wood ties on the bare ground, they'd slide around when trains went over them.  Also, they'd sink into the mud during rain.  The rock helps water run away from the track while making a more solid base than dirt.

Answer 7

It's called ballast, or ballast rock. It stabilizes the track and allows water to drain through. That's very important here in Minnesota where the moisture in the ground freezes for 6 months out of the year, causing the ground to contort. The ballast will act as a barrier between the track and the ground. Sometimes the track will become somewhat distorted, but usually not so bad that it can't wait until spring to be re-aligned.  I rode a 25 mph short line in AZ once that had no ballast. The ties sat directly on the dirt. That looked so odd to me.  Good question.

Answer 8

The stone used in track construction is called Ballast.  The gradation (size) of the ballast and construction of the track is governed by standards published by the American Railway Engineers and Maintenance of Way Association (AREMA).  The gradation of the ballast will vary depending on the type of line the track is.  Typically, if the track is a mainline, the stone will be AREMA #3 whereas a siding, leadtrack, or spur will use a smaller AREMA #5 Ballast.

The ballast provides the structure for the transfer of the train load to the subgrade (earth) as well as drainage for the track structure.  The load goes from the rail to the tie through the tie plate into the ballast into the sub-ballast and then into the ground (subgrade).  Typically, on a mainline, you will have 12" of ballast and 12" of sub-ballast below the tie.  On an industrial track, 6" of each of these layers is typical.  The depth varies to provide additional load distribution to the subgrade.

Sub-ballast is a much finer gradation than ballast and is also used in road construction as a base.  This sub-ballast is know as Aggregate Base Course (ABC) or more vernacular, as crusher-run.

The ballast also provides resistance to train braking.  Ties are "box anchored" every so often depending on the speed of the line, use and curvature.  Ties are box anchored using rail anchors.  These snap into place on the bottom flange of the rail and are placed snug against the tie on both sides on both rails.  When the train brakes the forces are transfered through the rails into the anchors.  The anchors transfer the force in the tie and into the ballast.  The ballast does not move because it is compacted (tamped).

Answer 9

I believe its to provide extra support and allow adequate drainage so that the tracks and wooden planks wont rot because they arent constantly in water.