Between passenger cars: vestibule, walkway, diaphragm?

It's all three. They are distinct parts of the connection between cars.

The vestibule is the part of the car where the door and boarding steps are located. Most streamline cars have one. Diners and baggage cars have none.

The diaphragm is the the flexible enclosure between cars use to keep most of the weather out.

The walkway as you call it would be the metal plates that bridge the gap between cars.

Superliners don't have the classic vestibule, as you board mid car on the lower level. The connection on the upper level just consists of a diaphragm and walkway plates.

Good description, Elliott.

Thanks Brian. I have a little first hand experience riding in the vestibule behind Milwaukee Road 261, hence the goggles to keep the cinders out of my eyes.

Thank you Bob for your question and thank you Elliot for your answer.

Always great info. on "OGR Forum."

Ralph

I love this forum!  Knowledgeable people willing to share.  I'm working on flexibly filling the gap in the diaphragms between 15" MTH California Zephyr passenger cars, and need the vocabulary to explain what I'm doing. Short video to follow in days. Thanks!

   Bob A.

You're welcome Bob. Clearly it's the diaphragms you are after. These are actually kind of tricky to deal with in 3 rail since the cars are expected to negotiate such tight curves. Long coupler shanks only exacerbate the the problem, making the gap unrealistically large. I'm anxious to see your solution.

I've now posted a short video (#29) of my solution on my YouTube channel. It works on my O-60 curves with no S-curves, but may not work on tighter curves. It won't satisfy hi-rail aficionados, but works for me to close the gap between the partial diaphragms on MTH 15" cars.

   Bob A.

That one put a smile on my face. really  nice job...,

Nice video, clever solution Bob.