In today's interlocking walkthrough, we're gonna take a look at the complex and known VALLEY interlocking on the bustling South Shore. To start, a special trait about VALLEY is that of all the railroad's interlockings, at least those that lie on Long Island. It's not supsrising, as VALLEY hosts 5 of the railroads eleven branches, including the Long Beach and Far Rockaway Branches as stopping services, and the West Hempstead, Babylon, and in some cases, Montauk Branch trains pass through (one very early reverse-peak Babylon train stops there). Valley Stream marks the end of the Atlantic Branch, and the start of the aforementioned 3 branches.
Here's an arial view of the entire VALLEY interlocking (don't worry I'll explain it well):
Sorry it's so small. Anyway, starting at the westbound end of the platform, there are four tracks. The two northernmost tracks are part of the Montauk Branch (Babylon, West Hempstead, and Montauk trains usually use these tracks). Therefore, the two southern tracks make up the Atlantic Branch which is used by Long Beach and Far Rockaway trains.
The first part of the interlocking consists of a cluster of different switches to the west of the station, there's a total of four crossovers. A train travelling eastbound from the Montauk Branch can actually switch onto any of the Atlantic Branch tracks, but not vice-versa.) The switches are designed in a way to allow Montauk Branch trains to stop at Valley Stream, though they rarely do.
The Atlantic Branch officially ends at the eastern tip of Valley Stream's platform, this marks 15.8 miles since Atlantic Terminal. East of here, the Atlantic Branch splits into two branches-the Long Beach and Far Rockaway Branches. The Far Rockaway Branch turns south via a weird pair of crossovers just east of the station and these trains can now go on their merry way for the 20 minute stretch to Far Rockaway. If you continue straight after the Far Rockaway branch diverges, it will land you on the platforms of Lynbrook. If you don't choose to head towards Long Beach, these trains could also choose to go on the VALLEY Lead Track, which is a electrified siding that is used to layup trains, specifically the old West Hempstead - Valley Stream shuttles that ran before ESA changes. The lead track eventually merges back to the Long Beach branch, before the final crossover and the interlocking ends.
Before East Side Access, the West Hempstead branch, as some of you know, was made up of these clumsy, bi-hourly shuttles that terminated at Valley Stream during the off-peak periods. The "natural, and current" path for West Hempstead trains is for a train coming off the branch to just join the Babylon Branch and then "leap" to Jamaica. However, before ESA, these trains had to have this clumsy, inefficient crossover move that required these trains to switch over 3 tracks in order to make the platform at Valley Stream to terminate. This is why many of the peak trains on the branch would just skip Valley Stream entirely. It's not hard to imagine what would happen if these zig-zagging West Hempstead trains were mixed in with rush hours.
Meanwhile that's going on, the Babylon Branch justs "plows through" without any restriction. I mean, the Montauk Branch doesn't really have switching movements as much of that occurs later down the line. There's one early reverse-peak service (I believe it departs Penn Station at 4:30 something) for Babylon that stops there, but other than that, these trains can just carry on their merry way without having to worry about a thing.
Hiding in the corner is the small, tiny, Valley Yard, which is a 3 track yard that actually isn't electrified and will normally store MOW equipment.
There's also VALLEY Tower which controls the Babylon Branch interlockings:
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| VALLEY Tower. Note the Far Rockaway crossovers. (Photo: The Position Light) |
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| Here's a nice look at the massive position light signals (Photo: The Position Light) |
I feel like this video by a friend of mine really captures the spirit of VALLEY interlocking, showcasing just how crazy things can get during rush hours. It's an important interlocking, as without it, there's no South Shore service. I remember hearing that back years ago when they redid the interlocking, there was no train service to it at all and they ran special dual-modes from Babylon Branch stations via the Mainline.