Former structure over Park Ave. viaduct? (NICK)

I remember from years ago, a brick structure around 110 St. (Estimate). The Steel it sat on is still over the tracks. What was was building and when/why did it come down?

Yes, I'm full of questions today.

Former NICK tower, formerly NK in the New York Central days, short for "New yorK." Someone else can answer the when's and why's.

I remember seeing Nick Tower back in the early 90s, but it's not there anymore, I used to like seeing that signal complex. Also, there's an interlocking at MP3.42, don't know what it is.

NK was at 106th Street, to be exact. And I think the interlicking you refer to at MP 3.42 is what used to be NK. The MP number sounds right

It is now being used to support 4 security cameras that can revolve 360 degrees and spy on whatever they want to.

Robert Paniagua wrote:(excerpt) ... Also, there's an interlocking at MP3.42, don't know what it is.

The former Nick interlocking, now called CP 3.
Home signals are at MP2.99 and MP3.35

Note: Interlockings with "no hundred" numbers are for the Hudson Line. (CP10)
100 numbers are on the Harlem Line. (CP 112)
200 numbers are on New Haven Line. (CP 216)

In a similar way, Radio channels step up on the main lines:
1 for the Hudson, 2 for the Harlem, & 3 for the New Haven.
The Hudson Line, from Mott Haven on down, is on Ch. 2. This
includes Districts M,P,U,L & Central Yard, since a lot of cooperation is needed.

(I liked it better when we were all on one, but it was a lot of chatter).

The NYC added NK Tower to relieve congestion which was caused by the lack of an intermediate interlocking between MO (Mott Havene Jct.) and Tower U at E. 56th St.

There were feature articles in both Railway Age and (IIRC) Popular Mechanics about the construction of the interlocking (a universal plant for the 4-track mainline) and tower, c. mid-1930's.

Prior to the building of NK, there was no way to get around a disabled train except to reverse direction all the way back to MO or U. NK gave the added operational flexibility to work around this situation as well as that caused by the need to do trackwork.

NK tower was rendered obsolete along with all of the other switch towers on Metro North
with the switchover to CTC.

Towards the of it's use it was staffed only one or two tours during the week, then opened as needed for track work, etc.