If you knocked I couldn't hear you.
I'm welding this LOCOMOTIVE engine.
The Big Bang Theory Season 10, Episode 15
So often, on the front of the LOCOMOTIVE...
The Big Bang Theory Season 8, Episode 21
"You are running the LOCOMOTIVE."
(GASPS)
The Big Bang Theory Season 10, Episode 15
I bought an N-gauge LOCOMOTIVE.
The Big Bang Theory Season 5, Episode 3
I hear LOCOMOTIVE smoke
is the second leading cause...
The Big Bang Theory Season 8, Episode 22