In this interlocking walkthrough, we're going to take a nice look at Harold Interlocking, one of the craziest on the LIRR. Harold Interlocking is where the LIRR's Mainline, Port Washington Branch, and even Amtrak's Hell Gate line all merge by the very very end into 4 tracks that go into the East River tunnels toward Penn Station.
It's important to note that Harold Interlocking has been changing recently, and will continue to due to the sheer size of the interlocking, therefore, things might be come inaccurate and I apologize in advance for that fact.
It's extremely difficult to portray this interlocking with any sense of organization, because of again, the fact that so much is going on at once, not only do we got those tracks, but we also got 2 of the biggest yard facilities in New York and the elevated (7) tracks passing by.
I'm going to make my best effort to explain the interlocking with the photos, references, and information that is available to me. As you can see below, it’s extremely difficult to understand this interlocking with any level of accuracy.
To the right, the LIRR’s Port Washington and Mainline branches and Amtrak’s Hell Gate line merge together, forming this interlocking. When they built this interlocking, they also built some flyovers to shuffle the tracks just slightly before entering the interlocking.
These flyover tracks are located just east of the interlocking, and they shuffle the tracks so all the westbound trains are grouped together by their destination, and all the eastbound trains are grouped together by their destination. For instance, there’d be one track for all the Hunterspoint Av. trains, a couple for Penn Station trains, and a couple more for Grand Central-bound trains. If your lucky enough to be onboard an westbound LIRR train, you should be able to tell what’s going on under these flyovers when there’s a brief period where it looks like you have entered the tunnel, but then come right back out (I remember always thinking you’d be in the tunnel but then I’d be surprised when we left so quickly back when I was a kid!)
By doing this, it makes things much more simple in the actual interlocking, as now trains only have to switch among tracks headed for the same direction, and there’s no need for risky and time consuming things such as crossover moves.
Once you get into the interlocking you can see two distinct sets of tracks…. Westbound and Eastbound.
By starting with the westbound tracks, the Port Washington Branch westbound track merges with Amtrak Hell Gate Line (this is the line that carries Northeast Regional and Acela services coming into New York Penn from places such as Boston and Vermont.)
West of this point, there are 3 main tracks that flow through HAROLD interlocking. Eventually, 2 of these tracks will become lines 2 and 4 into the East River Tunnels. The third will become a passenger track into Hunterspoint Avenue, and a couple others will go to Grand Central Madison.
Continuing west through the interlocking there are two parallel crossovers that allow trains from the two mainline tracks to shift over one track to the right, and later on, there’s another set of crossovers that allow trains from the northern tracks to move down to the lower ones.
In the midst of all this craziness, the unpowered North Engine Layup Track normally stores a protect engine. Protect engines, as you probably know, have the sole purpose as to jump in and rescue a train that has broken down. For some 50 years, the LIRR has supplied protect engines at HAROLD interlocking.
Due to the sheer size of this interlocking, I'm not even going to bother explaining the eastbound, however, I'm sure by looking at the diagrams you can get an idea.
The so called "zookeepers" of the interlocking set up shop at Penn Station Control Center, and HAROLD used to be controlled by a tower onsite bearing the same name, however, when PSCC opened, it moved there.
As you can see, HAROLD interlocking is one of the busiest interlockings in the country, and while it's definitely not perfect, it should definitely get credit for moving hundreds of trains into and out of the nation's greatest wonder- New York City everyday. I hope you've enjoyed this post and I got quite a bit of amazing things coming soon. Feel free to comment if you have any questions.