
...an outdoor museum
featuring 43 RAILROAD engines, cars...
The Big Bang Theory Season 4, Episode 6

Well, Sheldon was going on and on
about time zones and RAILROAD schedules,
The Big Bang Theory Season 9, Episode 16

You'd have to drive a RAILROAD spike into
his brain for me to beat him at checkers.
The Big Bang Theory Season 2, Episode 11

...a hot dog stand
in a converted RAILROAD dining car.
The Big Bang Theory Season 4, Episode 6

There are dozens of RAILROAD crossings
you have to blow the whistle for.
The Big Bang Theory Season 10, Episode 15