For millennia, manholes have been an integral element of human development. Ancient peoples dug tunnels and manholes to reach their subsurface water and waste systems. Manholes as we know them now did not appear until the Industrial Revolution.
Large-scale urbanization necessitated more advanced sewage network technology to provide adequate cleanliness. Cities like London and Paris began installing complete sewage systems with maintenance and repair access points in the middle of the 19th century. These passageways were the forerunners of the modern manhole covers.
In order to get access to subsurface utility systems such as sewage networks, stormwater drainage systems, water supply pipes, gas lines, and communications cables, a vertical aperture or access point is required. Manholes serve as safety features by preventing accidents, giving emergency access, and as maintenance and inspection points for these subterranean structures. They ensure the safety of pedestrians and motorists above ground and are thus an essential component of urban infrastructure. Manhole covers may double as inspection rooms.
Manhole Cover Maintenance and Why It's Crucial
In order to keep our cities safe and running smoothly, we must appreciate the need to maintain manhole covers properly. Manhole covers provide passage to underground infrastructure, including water and sewage pipes and communication cables.
Ignoring their upkeep can lead to a wide variety of issues, including potholes and deformations that cause vehicle damage. These loose covers present safety hazards, corrosion and rust that weaken their structural integrity, and water infiltration that leads to costly repairs and damage to underground utilities. Manhole covers should be inspected, sealed and coated, appropriately installed, and repaired as soon as problems are discovered to maintain their durability, improve the attractiveness of our cities, and increase the safety and well-being of walkers and drivers.
How Often Should Manhole Covers Be Serviced?
Many variables influence how often manhole covers need to be serviced. These include geography, traffic levels, weather, and the manhole covers' own construction and quality. However, in order for manhole covers to function properly and last as long as possible, regular maintenance is required.
It is advised that inspections and maintenance be performed at least once every six months in high-traffic areas in metropolitan centers or on roads with large vehicles traveling over them. Regular checks are necessary to spot any problems quickly in these high-use areas.
A yearly inspection and repair plan may be acceptable for less busy roads and lower-traffic regions. It's important to remember that certain areas may need more regular cleaning than others due to environmental considerations like severe weather or exposure to road salts.
Manhole Cover Types
Common manhole covers consist of:
Cast Iron Manhole Covers
This kind of manhole cover is by far the most prevalent on city streets and sidewalks. Covers made of cast iron are sturdy and can resist much foot activity. For extra durability, they often have a checker plate or solid pattern.
Ductile Iron Manhole Covers
Ductile iron coverings are just as sturdy and long-lasting as their cast iron counterparts. They are often utilized in high-traffic locations because they are more resistant to cracking and bending.
Steel Manhole Covers
Steel coverings are lightweight, making them an ideal choice when either portability or frequent access are key considerations. They find widespread use in industrial and low-traffic areas.
Concrete Manhole Covers
Sidewalks and pedestrian walkways, which see moderate to low traffic volumes, are ideal locations for concrete coverings. They're cheap but don't last as long as iron or steel.
Composite Manhole Covers
Composite materials like fiberglass or plastic are used to make these coverings. They're more portable than standard metal roofs and won't rust in salty air, so they're great for corrosion-prone areas.
Lockable Manhole Covers
Locks and other security measures on these coverings keep intruders from utility infrastructure. They are widely implemented wherever safety is a priority.
Hinged Manhole Covers
Access to the utility or maintenance chamber may be improved by using a lid with hinges rather than one that must be removed entirely. They find widespread usage in contexts where repeated access is essential.
Issues that arise when manhole covers are neglected
Unfastened or Loose Covers
When manhole covers aren't maintained, they can get unfastened. Covers that are too loose may cause serious accidents involving people and vehicles, such as tripping and falling.
Cracking and rusting
Moisture and road salt are only two of the environmental elements that may cause corrosion and rust to develop on manhole covers over time. The cover's load-bearing capability decreases as rust eats away at its structural integrity.
Potholes and Deformation
Deformation and potholes along the edges of manhole covers may be caused by high traffic volumes and the weight of passing cars. If not fixed, these distortions may harm tire tread and lead to accidents.
The Penetration of Water
Manhole covers that have been broken or improperly sealed may enable water to seep into sewage systems, which can lead to higher maintenance expenses and even damage to subterranean infrastructure.
Manhole Cover Safety Procedures & Recommendations
Routine Checkups
Manhole covers should be inspected often so that problems may be found and fixed quickly. Loose covers, rust or corrosion, and the state of the pavement around the unit should all be inspected.
Coating and Sealing
Protect manhole covers from rust and corrosion by applying a sealant or coating. Coatings should be reapplied often, especially in places with severe weather.
Cleaning and Polishing
It's essential to keep the area around manhole covers clear of debris to avoid the covers from being misaligned or otherwise damaged.
Evaluation of Capacity Under Load
Manhole covers should have the ability to support the weight of today's cars and high traffic volumes evaluated regularly.
Proper Installation
Manhole covers should be placed correctly and securely to prevent them from moving and posing a safety hazard.
Utilization of Locking Devices
It is recommended to install locking devices on manhole covers to prevent theft and vandalism from occurring.
Maintenance and Alterations
Manhole coverings that are damaged in any way should be fixed or replaced as soon as possible. Delays may lead to more damage and more expensive repairs if they aren't avoided.
Campaigns to Raise Public Conscience
Instruct the general public on the significance of manhole cover upkeep and solicit reports of any broken or missing covers they may encounter.
Working Together with Utility Suppliers
Coordinate maintenance activities with utility providers and guarantee the safety of the whole subterranean network.
Fusion of Technologies
Manhole covers may be monitored in real-time for possible problems by using cutting-edge technology such as sensors or Internet of Things (IoT) devices.
Manholes: Planning and Building
Depending on its intended use and location, manholes may be found in a wide range of sizes and configurations. Manholes are often shaped like circles, squares, or rectangles. Utility, pedestrian volume, and aesthetic preferences are all important considerations when settling on a layout. Manholes are often built from long-lasting materials like concrete, brick, or composites. The lid or cover of a manhole is reinforced to resist the weight of passing pedestrians and vehicles, and some models have locks for added safety.
A Manhole's Place in Today's World
Even though the modern city is always changing, manholes will always be necessary for it to work properly. Utility networks in growing cities become increasingly intricate over time, heightening the need for routine maintenance and well-designed access points. In neighborhoods with substantial architectural or historical value, manholes might even enhance the area's visual appeal.
Manholes, however, are also being modernized. Underground infrastructure is being monitored in real-time with the help of smart manholes fitted with sensors and data-gathering devices. This device may cut down on costly repairs by spotting leaks, clogs, and other problems before they cause significant interruptions.
Our Take
The inconspicuous manhole is an essential cog in the complex city planning and maintenance mechanism. In the past, they were just holes dug in the ground, but now they're highly complex nodes essential to the smooth operation of utility networks. Manholes will continue to play a crucial role in the development and modernization of our cities, serving as a constant reminder that we should value all aspects of our built environment.