Also known as a maintenance hole or utility hole, a manhole is often thought to only be used for sewage or wastewater management. But it is a vital part of several different underground systems. Each manhole is installed differently depending on its purpose and placement, whether that be in a high traffic city or in a small neighborhood.
Here are the 3 typical types:
Normal
A typical manhole is what you might see walking through the busy parts of your city. 5 feet deep and big enough to accommodate an average sized man, they are placed along sewer and stormwater lines in urban or high traffic areas and provide easy access for routine maintenance and repairs. This could be in the street or on the sidewalk, depending on where utilities are placed underground. Heavy covers protect anyone passing over the hole from falling in.
Shallow (inspection chambers)
Only 2 to 3 feet deep and covered by a lightweight lid, a shallow manhole’s main purpose is inspection. It allows engineers or repairmen to survey underground utilities, and provide limited maintenance to some shallower pipe lines. You’ll find them in low traffic areas over a “branch sewer” (a small sewer pipe that collects wastewater and sends it to a larger drain).
Deep
These are the manholes we usually see in movies that help the main characters escape.
When a manhole needs to be deeper than 5 feet it’s considered “deep” and has to include more safety features like ladders, lights, ventilation and emergency exits. Like a normal manhole, it’s characterized by a heavy lid and a large opening big enough for the average repairman. As the name suggests, they allow access to wastewater pipelines and systems that are deeper underground.
Each type of manhole is made with specific materials suited to their function and have to be maintained. In the next blog, we’ll discuss what goes into the rehabilitation of manholes and why it’s so necessary. For access to manhole installation or rehabilitation bids, open water pipe bids and other municipal water bids, subscribe to our database. For more interesting articles on similar topics visit our blog page.