What is the reason to put stone pieces (metal) under and around the railway lines.?
824316
Track ballast, consisting of gravel, cinders or other aggregate, forms the trackbed upon which railroad ties are laid. It is used to facilitate drainage of water, and to create an even running surface. This also serves to hold the track in place as the trains roll by. Such a track is also used to bring the Space Shuttle to its launching pad.\nIn the early days of railroads, much material for ballast came from rock found in the local area. In the Midwest, for example, much use was made of granite, while states in the southeast, such as Florida, made use of limestone. One specific type of granite used in the Midwest earned the name "Pink Lady" due to its color; in other areas, the ballast can be a mix of light and dark colors called "Salt and Pepper".
1145693
Granite and Marble are use to make Tombstones.
484891
to make their mark and territory. And if it still there years later, they'll look back and say "Hey, that's mine!"\n\nThough, I'm totally against hanging shoes on power lines.. what a waste of material. lol
966858
They were supposed to be metal?  I'd have never guessed.\n\nMetal didn't need saving.  It's done fine on its own.
393953
According to Rabbi Maurice Lamm (author of "The Jewish Way in Death and Mourning") the custom of placing stones on the monument "probably serves as a reminder of the family's presence. [The evidence that this grave is attended, visited and cared for, is respectful for the deceased - NS]. Also, it may hark back to biblical days when the monument was a heap of stones. Often the elements or roving vandals dispersed them, and so visitors placed other additional stones to assure that the grave was marked."\n\n\n\nAlso, by placing a stone we further participate in the "construction" of the tombstone -- which in itself constitutes a mitzvah.\n\n\n\nIncidentally, it is not a Chabad custom to place stones on tombstones
656252
It is because the round or circular shape is the most uniform shape of all (there are no edges or corners) - this means the amount of stress force exerted from the surrounding soil is uniformly distributed onto it; wheareas if it was some other shape with corners or edges, then stress concentration would be higher at those places, which would cause cracks/erosion that can destroy the pothole.
276560
This is sedimentation. It isn't foundations sinking, although that can happen. It's weathering products. Soil production is one way that things can become buried, as pointed out in the first answer, but for the most part, it is windblown, mass-movement, or water deposition that puts things that were initially on the surface underground.\n\nIt is important to note that there are regions of net deposition and those of net erosion, so not everything will always become buried. Sometimes it is subject to weathering itself. Large stone amphitheaters will fall apart and the pieces will be subject to weathering with will make them look like shapeless boulders. The only other way to get large boulders anywhere is by downhill mass movement, glacial transport, flash floods or by people putting them there.
206203
I think it's these metals chrome, cobalt, titanium, or ceramic materials can be used.  I think they have recalled ceramic because they were cracking though.
863956
Not an easy question at all. You haven't answered the other variables, such as the quality of the suspension on the train. There is a big difference between the latest model of Japanese rail comfort, and the old rust buckets that service the Indian countryside. Also counts if the track is banked (which it probably would be with such a short curve radius). And (unbelievably) which side most of the passengers are sitting on.
580607
Technically, anthing touching the ground is grounded.  A train is designed to take a lightening hit, with the exterior metal shell directing currents around internal passangers/freight and through the wheels into the ground.  No worries.
458407
Because they are made of solid metal.  This is necessary to withstand the various stresses it must endure transmitting the chemical energy created in the combustion chambers to the rotational energy of the drive train.
695474
Because they are only standing on a single cable. In order to be electrocuted, they'd need to complete a circuit to earth. \n\nIn the same way, standing on the live rail on a train track will not electrocute you, until such a time as you touch something else at the same time. \n\nPS although you'd be safe, I don't recommend trying it!
777760
Water pipes are getting unreliable as a lot of the main pipes are being replaced with non-metallic pipes. An earth rod is really the only reasonably certain earth. If you earth onto structural metal there is a chance that the metal may not earth and become live  if a fault occurs
239911
I also think that the snow, itself acting as a blanket covering, mutes the noise as the train passes.  Indeed, the corrision issue would likely cause railroads to shy away from such an idea, especially if real water was involved, which is very damaging to the tracks.
325433
the railroad industry uses this medthod to weld two rails\ntogrther. in 1968 i first witnessed it. the name of the compound exscapes me...this should lead you in the right direction.
282118
Because they're made out of magnetic material...iron I believe.
951097
the one who answered first... plzzzzzzzzzz\n\nexcellent answer but.. trains moving towards each other can also be said to move in opp directions.