Performing Directional Drilling Projects Throughout Chicagoland. Whether you are a large company or a small owner operator, let A & P Directional Drilling solve your underground problems. Underground lines and conduit can be installed using HDD (Horizontal Directional Drilling). This process uses drilling technology to bore a small hole from one location to the next. Once the drill rod comes to the end of the bore the new pipe is attached and pulled back eliminating open excavation. This technology can be used to install lines and conduit under roads, railroads, ponds, streams, industrial buildings, landscaping, etc. without the impact, expense and restoration of open excavation.