Concrete Manholes

A manhole or inspection chamber serves as a vital access point to underground utilities, including sewer and drainage systems. Constructed with durability in mind, these units allow maintenance workers to inspect, modify, clean, and maintain the essential services that run beneath our streets. By enabling safe entry to these utilities, manholes play a crucial role in ensuring the efficiency and reliability of municipal infrastructure. Proper maintenance through these access points prevents blockages and other emergencies, thereby protecting public health and the environment. Overall, manholes are indispensable for the upkeep and functionality of urban utility systems, making them an essential component of modern infrastructure.

Purpose of Manhole

The main purpose of a manhole is:

1. To perform inspection, cleaning, and removal of any obstruction present in the sewage line.

2. The joining of sewers, the change of direction or the alignment of sewers can be performed with the help of manhole.

3. These have a perforated cover which helps the foul gases to escape. Hence it is a good means of ventilation for the underground sewage system.

4. Manholes help to lay the sewer line in the conventional lengths.

Features of Manhole

Manholes play a crucial role in urban infrastructure, primarily consisting of a chamber or ring and a vertical circular pipe. These pipes come in various depths and sizes, providing essential access to inspection joints in the drainage system. Typically positioned 0.5 meters from the curb lines of roads, manholes are strategically constructed to avoid being in the direct path of vehicular traffic, ensuring safety and functionality. The cover of a manhole serves as a protective plug, preventing unauthorized access and safeguarding the system. Manhole covers can come in rectangular, square, or circular shapes, crafted from materials such as precast concrete, composite materials, or glass-reinforced plastic. This thoughtful design not only enhances accessibility for maintenance but also contributes to the overall safety and efficiency of urban drainage systems.

Types of Manhole

The three main types of manhole depending on the depth are:

1. Shallow Manhole

2. Normal Manhole

3. Deep Manhole

1. Shallow Manhole

A shallow manhole has a depth ranging between 75 to 90 cm. These are constructed at the start of a branch sewer or in an area where there is not much traffic. The shallow manhole is provided with a light cover called as the inspection chamber.

2. Normal Manhole

These are provided at the sewer line with a heavy cover on its top. It has a depth of 150cm. Normal manhole takes a square shape.

3. Deep Manhole

Deep manhole is provided at a depth greater than 150cm with a very heavy cover at its top. The size can be increased and the facility for going down is also increased.