Manhole

A manhole is an access chamber built over a drain or sewer that is large enough for an engineer to enter for inspection, cleaning or repair. In the UK, manholes are constructed in line with BS EN 752 and Building Regulations Part H, using precast concrete rings, in situ concrete or, on shallow private drains, modular plastic systems. Each manhole is fitted with a cast iron or composite cover rated for its expected loading, with heavy duty grades used under highways and lighter grades on driveways and footpaths. Step irons or ladders are provided where the chamber is deeper than 1 metre. Confined space regulations under the Health and Safety at Work Act 1974 mean that entry into deeper manholes requires risk assessment, gas testing and rescue arrangements.