Access to the sewer system is protected by usually a metal plate called a Manhole Cover, this not only provides an entry point for drainage engineers, but also protects pedestrians and other traffic above from the drains below. The early covers were made of slabs of stone or pieces of wood, but later through the industrial revolution, cast iron modern covers came to the forefront and became the industry standard throughout the country. They are mostly round in shape and are big enough to allow an engineer access to the drains to carry out maintenance duties or any other work they need to carry out e.g. repairs or replacements to the pipes in the system.
Manhole covers are usually made out of concrete, cast iron, or a combination of both. The outer metal base sits on a smaller inset rim that fits the cover and is secured with a cover lock to avoid any unwanted removal or theft.
Manhole covers are heavy (over 100kgs) and can be in an awkward position, so care should be taken when opening the cover to access the sewer and proper lifting aids should be employed to avoid any injury to the user.
Common Manhole Covers
There are a variety of manhole covers out there covering many purposes, here are some below:
- manhole cover that is double sealed
- cast iron manhole cover
- ductile iron covers
- septic tank covers
- manhole cover for sewers
- square or round lids
- concrete manhole cover