Where is it and how do it look like?
Example: Chicago,IL
http://img100.imageshack.us/img100/6207/10995463771b0d3b67ao0gw.jpg
:) :cheers:

Another one near O'hare Int. airport in rosemont:
http://charm.cs.uiuc.edu/users/olawlor/photos/places/Illinois/chicago/2002/air/dscf0036.jpg
:runaway:

For graf writers, this place is heaven :D

All the trains you can paint :D

For graf writers, this place is heaven :D

All the trains you can paint :D

LOL, oh yea baby!
This is da place to become great in urban graffiti! :eek2: :cheers:

Prolly not the biggest of the world, near Zürich (Dietikon-Spreitenbach)
http://www.luwi.ch/images/RBL/022_19.JPG

Anyway, Chicago does have some of the biggest (freight) yards in the world. In fact the city needs one this size since it's a centre of agricultural trade and trade between Chicago and other Midwestern farmlands.

This is the largest railroad yard in the world:http://img122.imageshack.us/img122/9039/baileyyard4py.jpg

This is located in North Platte,Nebraska.

edit

http://img162.imageshack.us/img162/3941/nebnplattehdr3qt.jpg

Probably World`s largest railroad yard is located in Germany. It`s Maschen Rangierbahnhof, with about 90 tracks alongside over 10 kilometers. Situated south of Hamburg in the Lüneburg Heath area. Across the broadest point there`s a viaduct especcially for train spotters.....

This is the largest railroad yard in the world:http://img122.imageshack.us/img122/9039/baileyyard4py.jpg
That seems to lack the density and scale of others shown so far. It looks more like 2 separate ones.

The world's largest classification yard is a hump yard: Bailey Yard in North Platte, USA. Other very large US hump yards are Elkhart Young Yard, (Chicago-) Clearing, (Kansas City-) Argentine, (Houston-) Englewood, Waycross Rice Yard etc. Specially in Europe (for exceptions - closures - see below), Russia and China, all important classification yards are hump yards. Europe's largest hump yard is that of Maschen near Hamburg, Germany; it is only slightly smaller than Bailey Yard. Most hump yards are single yards with one classification bowl but some, mostly very large, hump yards have two of them, one for each direction, thus are double yards, such as Maschen, Clearing, and Bailey yards.

Source Wikipedia.

courtesy of google map: here is the satellite view of an incredible railroad hump yard next to Chicago Midway Airport! It divided into 3 huge lump yards connecting continously with the center one being the largest, side by side, lost count of # of lanes, maybe you can give it a try and let us know! :)
Feel free to zoom in,out, and around to find more shocking railroad yards in chicago area! Chicago was considering one of the major railroad center of the US. So it is quite easy to spot them around chicago industrial areas!

http://maps.google.com/?t=k&om=1&ll=41.758508,-87.761021&spn=0.06377,0.11673

Alright and I found the satellite view of the railroad yard for the pic below:
:runaway:
http://maps.google.com/?t=k&om=0&ll=41.899051,-87.908735&spn=0.015908,0.029182

Another one near O'hare Int. airport in rosemont:
http://charm.cs.uiuc.edu/users/olawlor/photos/places/Illinois/chicago/2002/air/dscf0036.jpg
:runaway:

This one next to Chicago O'Hare Int. Airport, I think the pic below is what it looks like from nearby!
:runaway:
http://maps.google.com/?t=k&om=0&ll=41.945447,-87.89968&spn=0.015896,0.029182

Where is it and how do it look like?
Example: Chicago,IL
http://img100.imageshack.us/img100/6207/10995463771b0d3b67ao0gw.jpg
:) :cheers:

Just found another 2 parallel ones in the industrial park near Calumet city!
:runaway: :cheers:
http://maps.google.com/?t=k&om=0&ll=41.644408,-87.651114&spn=0.015971,0.029182

Another smaller one near Homewood
http://maps.google.com/?t=k&om=1&ll=41.573912,-87.655578&spn=0.015988,0.029182
:eek2:

Another one in Cicero(Gangster city) :runaway:
http://maps.google.com/?t=k&om=1&ll=41.573912,-87.655578&spn=0.015988,0.029182

You know what, there are way too many large railroad yards in Chicago,lol! If it doesn't have one single largest railroad yard in the world, might as well be the worlds most large railroads yards in the world. I think that the largest single railroad yard goes to North Platte,Nebraska(at least that is what Wikipedia said)
However, after seeing the satellite view of all the huge railroad yards in Chicago, I doubt that the one in Nebraska even consider large,lol! :)
:) :cheers:

Ok, just found the worlds largest single railroad classification yard in the world! :runaway: It does indeed slightly larger than the one near Chicago Midway ones and the one near O'Hare! It seperates into 2 parts. However, one thing that I like to say is that it is probabily the only large railroad yard in Nabraska! Unlike Chicago, it has many locations with everyone of them in same sheer size. Also, notice that this one in North Platte,Nebraska is locating in argriculture surronding indicating, it is most likely dedicating for argriculture and live stocks of some sort, while chicago has almost all kinds of things! :) :cheers: :eek2:

http://maps.google.com/maps?f=q&hl=en&q=North+Platte,Nebraska&ll=41.150773,-100.829816&spn=0.016093,0.040855&t=k&om=1

Out of curiosity, how are tracks in Europe numbered? In Yards and also mainline.

For example, an American yard will be numbered simply track 1, 2,... from south to north (or other convention, based on the railroad).

One rail system I know has a central point and the mainline (double track) is numbered track 1 away from the central point, and track 2 goes to (two) the central point.

Occasionally, mainline has three or four tracks, track 3 parallels 1 and 4 parallels 2.

Yards start at track 10 (closest to mainline, but not necessarily next to mainline track 2, could be next to 1). And go up from 10 - 11, 12, 13 ... (quite siomple).

railyards of Kansas City(city with the most miles of railroad tracks in the world)
https://maps.google.com/maps?hl=en&ll=39.085321,-94.682815&spn=0.013125,0.025706&t=k&z=16

https://maps.google.com/maps?hl=en&ll=39.125616,-94.52199&spn=0.013117,0.025706&t=k&z=16

https://maps.google.com/maps?hl=en&ll=39.138382,-94.584045&spn=0.006557,0.012853&t=k&z=17

https://maps.google.com/maps?hl=en&ll=39.140471,-94.558479&spn=0.006557,0.012853&t=k&z=17

https://maps.google.com/maps?hl=en&ll=39.178797,-94.430687&spn=0.013107,0.025706&t=k&z=16

new yard underconstruction
https://maps.google.com/maps?hl=en&ll=38.789683,-94.956765&spn=0.026359,0.051413&t=k&z=15

http://img-fotki.yandex.ru/get/6414/30348152.144/0_69723_e96e1c68_orig
http://gelio-nsk.livejournal.com/179244.html
Yekaterinburg-Sortirovochniy(formerly Sverdlovsk-Sortirovochniy). Classification Yard.
The largest yard in USSR(CIS) and therefore in Russia.
It has 2 humps and 76 tracks in it's widest part.


and
http://img-fotki.yandex.ru/get/6422/30348152.13e/0_6881e_109804f6_orig
http://gelio-nsk.livejournal.com/177638.html
Inskaya. Located in Novosibirsk.
The second largest in Russia.
It has 68 tracks.

Beograd-Makis station in Belgrade, Serbia has 62 tracks in total. It’s a hump yard with 175 switches and 70 km of tracks in total. It also has a maintenance depot and a hotel for the railroad workers.

http://binged.it/13Vham3

I couldn't find a better image other than a Bing's Bird's Eye View, but Montréal's rail yards are pretty big.

Here's (http://maps.google.com/maps?q=Montreal,+QC,+Canada&hl=en&ll=45.468137,-73.662729&spn=0.035093,0.077162&sll=37.0625,-95.677068&sspn=40.460237,79.013672&oq=montreal&hnear=Montreal,+Quebec,+Canada&t=h&z=14) a link to Google Maps.

http://i.imgur.com/8MH6Fsn.jpg

Tulsa, OK Railyard .... not the biggest, but good sized:

https://maps.google.com/maps?hl=en&tab=wl