So within half an hour he was at work, far underneath the streets of
the city. The tunnel was a peculiar one for telephone wires; it was
about eight feet high, and with a level floor nearly as wide. It had
innumerable branches—a perfect spider web beneath the city; Jurgis
walked over half a mile with his gang to the place where they were to
work. Stranger yet, the tunnel was lighted by electricity, and upon it
was laid a double-tracked, narrow-gauge railroad!

But Jurgis was not there to ask questions, and he did not give the
matter a thought. It was nearly a year afterward that he finally
learned the meaning of this whole affair. The City Council had passed
a quiet and innocent little bill allowing a company to construct
telephone conduits under the city streets; and upon the strength of
this, a great corporation had proceeded to tunnel all Chicago with a
system of railway freight-subways. In the city there was a combination
of employers, representing hundreds of millions of capital, and formed
for the purpose of crushing the labor unions. The chief union which
troubled it was the teamsters’; and when these freight tunnels were
completed, connecting all the big factories and stores with the
railroad depots, they would have the teamsters’ union by the throat.
Now and then there were rumors and murmurs in the Board of Aldermen,
and once there was a committee to investigate—but each time another
small fortune was paid over, and the rumors died away; until at last
the city woke up with a start to find the work completed. There was a
tremendous scandal, of course; it was found that the city records had
been falsified and other crimes committed, and some of Chicago’s big
capitalists got into jail—figuratively speaking. The aldermen declared
that they had had no idea of it all, in spite of the fact that the
main entrance to the work had been in the rear of the saloon of one of
them.

London also had an underground freight railway - to carry mail. It was inuse around 10 years ago, but I’m not sure if it’s running anymore.

There’s some pictures here: http://www.railfaneurope.net/p.....O/pix.html

Most of the tunnel system is now used for cabling - power and communications. Few adventurers know of undocumented entrances.

The floodwaters did enter through one of these tunnels, but the hole was caused by a bridge piling damaging the tunnel. The underlying problem was that these tunnels weren’t properly documented or surveyed.

It was indeed a collapse of one of these old tunnels that caused some flooding in the early 90’s.

Check out http://en.wikipedia.org/wiki/C.....el_Company or Google “chicago freight tunnel system”

http://users.ameritech.net/chi.....nnel1.html

http://www.lowtechmagazine.com.....thout.html