Underground Duct Bank Extensions


Over the years, we have installed underground duct bank systems for numerous customers, such as college campuses. These large groupings of conduits—usually concrete encased—serve everything from primary systems to secondary service entrances, fiber, phone, fire alarm and the like. Usually the various system conduits that comprise the duct bank are accompanied by spare conduits, connecting the start and finish of the respective runs with an additional means of cable routing. This works fine if the present building is the only one ever to be served…but what happens if you need to extend services to a different building?

Many times over our history, we have excavated midpoints of duct banks, to tap into the run of a spare conduit, system conduit, or etc. We have made custom concrete manholes with notched bottoms to “saddle” over the existing conduit runs. This allows us to excavate and expose the conduits that we want to enter—which often calls for jack-hammering the concrete encasement (on de-energized conduits)—cutting out a section of the conduit to make an access point into the run, then dropping the saddle box over the entire application and backfilling. Once this box is in place, we are able to trench from our new final location to the ground box, rather than trenching all the way back to the feed source of the relevant system. Many times we have saved our customers significant expenses, not to mention any unnecessary soil excavation.