From time to time we have to extend or replace utility services to a building which may require excavation in the public street right-of-way. Working in the streets brings its own challenges, typically getting the proper permits, inspections, etc to complete the job as planned. The jurisdictions are generally very good about identifying and locating any underground utilities so that the work can avoid disruption to those existing utilities.
Earlier this year my older brother that lives in Brooklyn, New York had to replace the sewer line to his home. His contractor was familiar with doing such work and everything went as planned. But one thing they had to deal with was a 68″ sanitary sewer pipe! It is hard to see in this photograph, but what appears to be a lump of soil at the top end of the trench, right around the workers feet, is the 68″ diameter sewer pipe. There were other smaller pipes to excavate around, as well as various gas and communication conduits. The excavation has been cribbed and braced for the workers safety. But no matter what you do to the trench, it is a lot of work to excavate under a 68″ sewer pipe to install the new utility line.
Seeing this type of construction makes me realize how difficult it is to coordinate and perform construction projects in dense urban cities. There is no room for staging or storing materials. People need access to areas at all times. And above all, you don’t really know what you will find in streets that have been in place for 200 years.