Table of Contents
What is Manhole?
A manhole is an underground chamber to provide access to the utilities like a sewer system, drainage system, etc.
We can inspect, change or maintain underground utilities with the help of manholes. Manholes are covered and can be open only for maintenance purposes.
Gas tests should perform prior to entering the manhole because toxic gas can cause harm to the workers. Inhalation of toxic gas such as H2S can cause immediate death.
A manhole is a confined/restricted area. It required a proper entry plan before entering into the manhole.
Some Important Purposes of Manhole
Here are some purposes of the manhole.
- To carry out inspection, cleaning, and evacuation of any obstacles that exist in the sewage line.
- The connection of sewers and the change of direction of the pipeline can be carried out with the help of a sewer manhole.
- Manholes have a perforated cover which assists the foul gases with getting away. Consequently, it is a decent method for ventilation for the underground sewage framework.
- Manholes assist to lay the sewer line in the customary lengths.
Types of Manhole
3 types of manholes are based on depth.
- Normal Manhole
- Shallow Manhole
- Deep Manhole
Let’s talk about these three types of manholes.
1. Normal Manhole
This type of manhole is installed in the sewer liner with a heavy cover on its top. It has a depth of 1.5 meters. The shape of a typical normal manhole is square. But is not necessary, it can be round or any other geometrical shape.
2. Shallow Manhole
The normal depth of a shallow manhole is between 0.75 meters to 0.9 meters. Shallow manholes are created at the start of a branch sewer or in an area where there is low traffic. there is a light cover fitted with shallow manholes called an inspection chamber.
3. Deep Manhole
This type of manhole has a depth greater than 1.5 meters. there is a heavy cover installed on its top. The size can be enhanced and the facility to go down can be changed based on the location.
These were three types of manholes. If you have any questions don’t hesitate to comment below.