Tag Archives: Engineering

I got to the MTA’s Substation #13 through the New York Transit Museum recently. The substation converts high voltage AC electricity from the grid and converts it to a lower voltage DC electricity that is used to operate subway trains via the third rail. The substation was originally built in 1904, and it fits into the category of “they don’t build them the way they used to.” The outside looks like a nice neighborhood building, and it has architectural aspects that I really wouldn’t expect from a substation. For example, an interior staircase has lovely decorative balusters.

Exterior of the Substation #13

Gorgeous stairwell inside the substation

Inside the substation are large rotary converters, specifically Westinghouse 1,500 kilowatt Rotary Converters. The rotary converters are what used to transform the AC electricity to DC electricity. Now modern solid state rectifiers are used to transform the electricity, and they are much more compact. The old rotary converters were used until 1999, when this substation was switched to the new equipment.

Westinghouse 1,500 kilowatt Rotary Converter

Westinghouse 1,500 kilowatt Rotary Converter

Positive and negative brush arms of Westinghouse 1,500 kilowatt Rotary Converter

Our guide was retired general superintendent Robert Lobenstein, who showed us around. He also showed us how workers used to have to do normal work, like changing switches and listening for crackling to make sure a wire was not live.

How workers used to change switches

We got to go into the basement which had all sorts of old equipment.

I have no idea what this is, but it is cool looking

We even got to go into a vault under the street where cables left the substation to go to the subway. The vault can be accessed through a door in the basement or through a manhole in the street. Normally this type of vault could only be accessed through a manhole. The cables go through conduits that are buried under the street. The cables are tagged, but it still looks like it would be difficult to find the right one if needed.

Cables leave the substation through the vault under the street with manhole access

Inside a manhole. The manhole access is visible in the center of the ceiling.

Back inside the basement, some of the equipment was still being used, but some was no longer needed, like some massive cables that were cut.

Old cut cables

Cables come in from the ground from the grid and are then split before going upstairs to the transformation equipment.

We then went upstairs were the new equipment was, including the solid state rectifiers and the biggest breakers I have ever seen. The breakers are in the circuit with the third rail. They detect surges in the third rail and cut off power before a fire or some other damage can occur. There is a lot of redundancy with the circuit breakers. Our guide turned one off, so we could hear how loud it is, but because of redundancy, it had no effect on the subway.

Circuits connecting to breakers

Breakers for the third rail. The copper plates are the third rail.

The solid state rectifiers are very different in appearance, at least, from the rotary converters. [I understood very little about this.] What amazed me during the tour, was when I finally understood I was actually staring at the third rail. The long copper plates in the photos are the third rail, which leave the substation and go to the subway. The positive rail is the equivalent of the black or red wire in a house’s wiring. The negative is the equivalent of the white wire in a house’s wiring.

Third rail leaves the rectifiers. The positive rail “POS” goes to the subway. The negative rail “NEG” goes to a central location to complete the circuit.

Also upstairs was this amazing old series of electrical switches, dials, and gauges. None of this stuff is used anymore, but it really cool looking. I liked how everything was tagged out, never to have the tags removed again and be turned on again.

Old switches that are no longer used

Gauges

Finally at the end of the tour, they turned on the rotary converter for us. Below is a video if you want to see it in action. It is almost hypnotic. During a portion of the video, you will see five lightbulbs on a wooden board sitting on the floor. They are being powered by the converter. After it is turned off and slowly slows down, the lights dim and then turn off.