[ssegraves]

I worked on some small pieces of things mentioned in the article, specifically around the maintenance and reliability of the underground network in Manhattan.

There is a mix of submersible transformers and those that can handle water but can't be submersed in the city. The former are usually placed in areas that are prone to flooding, they are much more expensive than a regular transformer since they are basically waterproof and have a number of extra features built into them so they require less maintenance.

In Manhattan proper, the worst enemies of the underground network are salt + water and the build up of gases. Salt and water + eletricity = corrosion which leads to burnouts. There has been a significant move to try and preemptively visit underground vaults and clear them of the salty water after a snow melt.

Most underground cabling is enclosed in an oil filled casing. Over time these wear and leak. Those gases can fill the underground transformer vaults and lead to explosions. These events are usually pretty well documented and again, ConEdison has been putting procedures and inspection routines that help prevent these.

What is amazing about the Manhattan and Brooklyn networks is how resilient they are simply by the simplicity of design. A transformer outage in a certain area can go almost completely unnoticed by citizens because of the control centers around the city and how they will reroute power. It's something that doesn't exist just about anywhere else and allows crews to isolate issues and perform maintenance when needed.