manhole

A manhole is an access point to underground public utility networks. Found in streets, sidewalks, and other paved areas, manholes allow authorized personnel to inspect, clean, repair, and upgrade buried conduits and chambers such as sanitary sewers, storm drains, water mains, electrical cables, and telecommunications ducts.

A typical manhole consists of a vertical shaft or chamber lined with masonry, precast concrete, or polymer materials, capped by a removable cover. The cover is usually made of cast iron or composite material and is designed to withstand surface loads. Access is gained via ladders or fixed rungs inside the shaft.

Common types include sewer manholes, stormwater manholes, and utility or inspection chambers. Some systems use smaller junction boxes or pull boxes for telecommunications and electrical networks. Manholes are spaced along a network for access, venting, and drainage cross-overs.

Hazards include confined-space conditions, toxic gases, limited oxygen, drowning risk if water is present, and falls. Safety practices require proper air testing, lockout/tagout when appropriate, and use of PPE and confined-space procedures for entry.

Standards and construction practices vary by country. European and other jurisdictions often reference EN 124 for covers and frames, while other regions specify load ratings and dimensions in local codes. Regular inspection and maintenance are performed to prevent blockages and structural deterioration.

Historically, modern urban drainage systems emerged in the 19th century; manholes became standardized components in many cities to provide access for maintenance and system upgrades.