Grand Central Terminal
Track, Signal, and Interlocking Diagrams


by Peter R. Samson
(to home page)


Here are drawings showing the tracks, signals, and locking of Grand Central Terminal in its “Glory Years” — from 1931 into the 1960s. In this period it hosted long-distance trains, including streamliners like the Twentieth Century Limited, as well as intensive commuter services to suburbs in New York State and Connecticut. By late in 1931, a number of track changes were completed to accommodate longer trains; the layout changed very little from then until the advent of Amtrak in 1971. (Since then there have been considerable changes, and the interlockings were all replaced in the early 1990s.)

Legend for track plans
Track plan — approaches (Tower U)
Track plan — upper level (Towers A, C, FA)
Track plan — lower level (Towers B, FB)

Explanation of locking sheets
Locking sheet — Tower U
Locking sheet — Tower A, section 1
Locking sheet — Tower A, section 2
Locking sheet — Tower A, section 3
Locking sheet — Tower A, section 4
Locking sheet — Tower C
Locking sheet — Tower B, section 1
Locking sheet — Tower B, section 2
Locking sheet — Tower B, section 3
Locking sheet — Tower B, section 4

Thanks to Jeff Birkner for access to many of the source documents.

Many fine books offer more general information on GCT. Some I particularly enjoy:
Grand Central, David Marshall, Whittlesey House (McGraw - Hill), New York, 1946. History and human interest, but a good overall view of the technicalities too.
The Port of New York, v. 2: A History of the Rail and Terminal System from the Grand Central Electrification to the Present, Carl W. Condit, University of Chicago Press, Chicago, 1981. Condit wrote this as a professor of history, urban affairs, and art history at Northwestern, but his first career was as a civil engineer for the New York Central. His knowledge of Grand Central Terminal is profound and intimate; the book is a classic.
Grand Central: Gateway to a Million Lives, John Belle and Maxinne R. Leighton, W. W. Norton, New York, 2000. Brings the story up to date by describing the superb refurbishment of the terminal building itself (the Head House). Many good photographs, though not of tracks and trains.