Manholes allow access to underground piping, meters, and facilities. Manholes perform a variety of functions. They allow access to meters, which read liquid flows to things such as sanitary sewer lines. They allow access to underground cables and telecom facilities and serve a variety of other functions. Manhole access ports are sometimes referred to as manways. Construction, dimension specifications, manhole cover specifications, and features are all important parameters to consider when searching for manholes and manhole covers.

Specifications

Construction specifications to consider when selecting manholes and manhole covers include materials of construction, shape, and application. Common materials of construction include precast concrete, fiberglass, and polyethylene. Precast manholes are usually made of concrete produced in sections at a factory and assembled at the site. Fiberglass is used with plastics to create an environmentally sound and strong structure. Polyethylene is a type of plastic used in the construction of manholes. It is highly corrosion resistant and environmentally safe. The shape of manholes and manhole covers can be round, square, or rectangular.

Important dimension specifications to consider when searching for manholes and manhole covers include length, width, height, and diameter.

Applications

Common applications include:

• communications manhole
• meter manhole
• power manhole
• replacement liner
• sewer manhole

Specific manhole cover configurations include hinged flat, removeable flat, hinged dome, removeable dome, and highway traffic. A hinged flat manhole cover is attached to the manhole on top and allows access. The covers are available in various shapes. Removable manhole covers are very common in street utility applications. The cover is removed completely to gain access. A hinged dome manhole cover is a rounded device that is connected via a hinge. A removable dome is a domed cover that can be completely removed to gain access to the manhole. Highway manhole covers are high-strength covers used in heavy traffic areas.

Features

Features common to manholes and manhole covers include integral flumes, access ladders, gas detectors, lights, power outlets, and vents. Flumes are integral, watertight chutes that are built into the manhole. An access ladder allows a person to climb into the manhole. Gas detectors measure the level of gas in the manhole. They usually have an alarming device connected to signal a dangerous situation. Integral lighting is built into some manholes. Power outlets can be located inside the manhole. Some manholes have the option of motorized and non-motorized vents.

Related Information

CR4 Community—Nozzle/Manhole Neck Materials

CR4 Community—Manhole Covers

IEEE Spectrum—Urban Robots Could Use Manholes to Navigate

IEEE Spectrum—Smart Sewers Will Reveal What's in Cambridge Citizens' Guts

Image credit:

David Buchwald / CC BY-SA 3.0