On Tue, 24 May 2005, Clive D. W. Feather wrote:

In article , Tom Anderson
writes

The discussion says that something called a '4-track relay terminal
with a 2-track relay' used to exist at Park Row on the New York subway.
No idea what that is, but the poster seemed to be impressed.

I asked a knowledgeable friend.

Firstly, it wasn't on the Subway but on the erstwhile Brooklyn Bridge
Railway, at the Manhattan end. Turning it into UK terms, the layout would be:

####D####
/--------------\
|------* ####A#### \
\-----------\ /--*----
X
/-----------/ \--*----
|------* ####D#### /
\--------------/
####A####

The platforms marked D were for departing passengers and A for arriving
ones.

Wow. I can't even begin to figure out what the capacity of that would be!

Do trains drive on the left in the US, then?

The X is a simple diamond crossing without slips.

Is the entirety of railway terminology invented purely to wind me up?
I'm guessing a diamond crossing is just where two pairs of rails cross;
switching to line-per-rail mode:

\ \ / /
\ \ / /
\ \ / /
\ X /
\ / \ /
X X
/ \ / \
/ X \
/ / \ \
/ / \ \
/ / \ \

Is that right? If so, what's a slip?

tom

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