GATE Interlocking is not that far from HAROLD, and it consists of a simple pair of crossovers just to the north before the tracks break away from each other. The diagram below shows what goes on in this minor interlocking.
GATE Interlocking gets its name from the Hell Gate Bridge that it lies at the foot of (or the Hell Gate Line it starts on, either one). Trains come from HAROLD interlocking and New York Penn Station from the bottom of this diagram. The Hell Gate Bridge and New Rochelle all lie past the upper limit of the image.
There are two tracks that come from HAROLD Interlocking, an eastbound and a westbound track. The two come out of HAROLD interlocking in different places put eventually converge and run right next to each other. GATE interlocking lies not too far away, and there is a crossover from the eastbound track to the westbound track, and a crossover from the westbound track back to the eastbound track.
GATE Interlocking is also commonly referred to as the location of the phase change in the overhead wires. While the actual phase change is located just to the east of the interlocking (compass north), saying GATE interlocking is a lot easier than saying "the phase change at milepost 5.something." At this phase gap, the power system in the overhead wires changes. North of the phase gap (up to the Metro-North tracks and as far as the next phase gap just east of New Haven), the overhead power lines are supplied with 12,500 volts of electricity at 60 cycles per second (hertz). South of this point, electricity is supplied in the form of 12,000 volts of current at 25 hertz. Many years ago the section north of this point was converted up to a 60 Hz traction power system, however it was felt to be too complex to do everything south of this point all at once, so from this point south, much of the NEC sees the 25 Hz power lines, many of which date back to the days of the Pennsylvania Railroad.
All of Amtrak's electric locomotives have the necessary equipment to negotiate this phase gap with little effect on the passengers. Trains cannot draw power while operating over the gap, but other than that, they can easily coast through and liven up on the other side (and this is done dozens of times a day by Amtrak locomotives). NJTransit's ALP-46 (and their fancy new ALP-45DP's) also have the necessary equipment to cross the phase gap. (And this is the reason why NJTransit equipment is used to provide the New Haven Line Meadowlands train on Sundays during football season). While rare, MARC and SEPTA electric locomotives can also bridge the gap, since they are almost exactly the same as the HHP-8s and AEM-7s that Amtrak operates.
Other than these types of equipments (in addition to obviously the diesels which can operate no matter what kind of wire is above them), there is no other rail equipment in the area that can negotiate this phase gap. This condition notably includes Metro-North's M8 cars. A train of M8's cannot currently go from the New Haven Line into Penn Station via this route under its own power. It could get as far down as this phase gap point, but once it gets past, the train either grinds to a halt or all of the AC equipment explodes (perhaps not explode, but there would definitely be some sparks). This is one of the notable obstacles to Penn Station Access, because (as I mentioned more in this post), over a mile of third rail would have to be installed in order to allow for the M8's to transition to third rail power before hitting that phase gap. The M8's were originally planned to feature equipment that would allow it to operate on both sides of the phase gap, but the 25 Hz equipment was dropped from the design due to concerns about weight.
The map I have embedded below shows some of the different physical characteristics of the area (i.e. what lies where, and where everything changes). GATE interlocking is a key transition point where the older infrastructure meets the newly added (new in relation to everything else built in this area). If you subscribe to the site by e-mail or RSS, you may have to view this post in your web browser to see the map:
You will also see what looks like to be a black track sneaking into the above diagram. This track is the New York Connecting Railroad track. It connects CSX's Oak Point Yard to FREEMONT, which is right next to the New York & Atlantic Railway's main Fresh Pond Yard. Much of Long Island's freight comes in and out on CSX over this route. At this location, you can see where the two tracks run together, however, there are no physical track connections between the New York Connecting Railroad and the Hell Gate Line at this location. And in fact, there are no physical track connections until you are miles into the Bronx. This track is not electrified and trains move at slower speeds, since it is designed and maintained for freight movements only.
CSX will bring a train down over the bridge and over this track nearly six days a week these days. They meet NY&AR crews at FREEMONT and trade cars there. NY&AR takes inbound cars from CSX and delivers them to Long Island customers, while NY&AR sends cars back out. This is all part of the long process by which freight cars move off Long Island.
Technically, it is possible to go from Jamaica to Penn Station using this as an alternate route to the LIRR's Mainline. It's not a very practical option, as it would entail having to go west down the Lower Motnauk Branch to Fresh Pond, around the curve up to FREEMONT, reverse directions and operate up the NYCRR track into the Bronx and up to PELLHAM interlocking, reverse direction again, and come down the Hell Gate Line all the way into Penn Station. It wouldn't fly in any regular scenario, as you could probably clear up any disruption in the time it would take to get form Jamaica to Penn Station via this route. Though if it was an absolute emergency (like the entire Mainline would become inaccessible for weeks), such a routing could be possible (in addition to going down the Lower Montauk via Long Island City, which is probably a more practical route to start with.)
I will have more on the New York Connecting Railroad and its piece in the rail puzzle on Long Island in a later post. But for now, we'll wrap up this particular walkthrough and set our sights on a look at PELLHAM interlocking next Wednesday.
