So often, on the front of the LOCOMOTIVE...
The Big Bang Theory Season 8, Episode 21
I hear LOCOMOTIVE smoke
is the second leading cause...
The Big Bang Theory Season 8, Episode 22
If you knocked I couldn't hear you.
I'm welding this LOCOMOTIVE engine.
The Big Bang Theory Season 10, Episode 15
If you listen carefully when
the LOCOMOTIVE disconnects,
The Big Bang Theory Season 7, Episode 15