It is likely that the maximum interaction you have had with manholes were while being on the road. Manholes are basically access points to gain entry to the underground sewer systems, storm drains, pipes and pipelines for inspection and maintenance. Did you know that without manholes, there would be no way to check out the metres-long sewer pipes and lines that lie beneath the surface of the road? As much as the manholes are essential for the smooth removal of sewage and fluids, manhole covers are also equally important. Below are the reasons why manhole covers are important in roads and utility areas.
Functions of Manhole Covers
- Allows entry to maintenance staff
There are various pipelines underground devoted to municipal utilities, including electrical and sewer lines beneath the streets. Without manhole covers, it would be an impossible task to get to a point of issue under the ground. A manhole cover makes it easy for maintenance personnel to get down into the passage through the built-in ladders and carry out repairs, inspections and maintenance.
2. Reduces risk of accidents
Manholes are generally found in the heart of streets, business districts, or gardens—anywhere where drainage and access to it are necessary. Manhole covers serve an essential purpose in municipalities, neighbourhoods, as well as in commercial properties. Without manhole covers, the entrances to the underground sewers and utility vaults would simply be holes in the middle of the road or footpath. Uncovered, these manholes in pedestrian and traffic-heavy areas would pose a severe threat to safety. Besides keeping pedestrians safe, they also help prevent the entry of unwanted materials into the sewer canals or utility vaults beneath.
Why are manhole covers positioned in the middle of roads?
You may have wondered why manhole covers are positioned in the middle of the roads. Well, here are the reasons. Maintenance work in the sewer lines can reduce the convenience of pedestrians who use the footpath or sidewalk. Such a disruption or obstruction in the path can compel them to use the road which can be risky. It can also cause disturbance to vehicular movement on the streets, leading to chaos and confusion.
However, when a manhole is placed in the midst of a street, the scenario is different. If maintenance work is to be done, a section of the road might simply be closed off, or diverted to another section. While drivers may face difficulties for a while, it allows smaller vehicles and pedestrians to securely stay on their designated sides.
How to choose manhole covers?
Manhole covers come in a variety of forms, but they all share the same obligations to safeguard and benefit the environment in which they are installed. But, how to choose the appropriate manhole cover?
- Type of Manhole
Before finalising on the type of cover for a manhole, the area of application is essential. Depending upon the depth of the manhole, the type of manhole cover can be chosen. Typical manholes which are less than 150 cm deep can work with thin yet sturdy square or rectangular manhole covers. Such covers are common in utility areas. For areas with heavy-traffic, round or circular-shaped covers suit the best.
- Weight Loading
Depending upon the amount of weight the manhole cover has to withstand on a daily basis, the selection is done. Covers for manholes have different load ratings, ranging from A15 to F900. Light pedestrian activity can be handled by the covers which are lower on the rating chart. For extreme heavy duty applications, covers which are towards the higher end of the load rating are ideal.
- Type Of Material
Different material options are available when it comes to manhole covers. Steel (galvanised and stainless), iron (ductile and cast), polypropylene and aluminium are some of the commonly used materials. Cast iron and galvanised steel are, however, two of the most popular materials for covers of manholes. The individual materials are ideal for their own set of advantages in terms of durability, area of application as well as aesthetics.
- Functionality
Not all manhole covers are used to keep access away from large storm drains or sewers. Some of them which are installed at lawns, gardens or backyards are typically different from the ones used in roads, airports and docks. Recessed round/square shaped manhole covers are preferred for maintaining the aesthetics of the area of application, while multipart covers are ideal for accessing storm or sewer lines.
While it may not be evident in general, manhole covers play an essential role in the maintenance and upkeep of the physical infrastructure, and hence they should be sourced from authentic sources. Renowned manhole cover manufacturers in India like Crescent Foundry offer the best quality covers according to the purpose and requirement of the application.
