These are found in almost every neighborhood. Though they are quite essential for a couple of reasons, they can cause serious accidents and deaths too.
In this article we would look into these high-functioning structures and how they pose threat to life.
What are Manholes?
These are openings of chambers that are sometimes linked to other chambers or sewer channels usually below ground level. The manhole serves as the access or entrance above or on ground level.
The spaces they lead to serve varying purposes from carrying sewage, drainage systems (e.g. the one that facilitates draining of flood waters from our roads and streets), and chambers housing wiring.
The dangers of Manholes
Manholes by themselves in perfect conditions don’t pose any threat as such.
Scenarios where they do;
- Uncovered manholes
This is a very careless and common situation with some manholes. Unsuspecting people fall in to these, sometimes due the heavy rain and flooded roads, and no sign up to inform the road users that there is an uncovered manhole, people fall in, drown and are swept off by the fast moving water. Manholes should remain covered when there is no need to access the chambers below. If the manhole is there for drainage purpose at least a grate can be used as covering.
- Manholes with defective covers
Defective covers are really dangerous because a person not careful enough, could step on these and fall in too. They will suffer just as much if not more injuries.
When a manhole covering is broken or loose, as soon as it is observed it should be reported to the appropriate government office and fixed to prevent accidents from occurring.
- Climbing into manholes without skill and appropriate gear
A manhole is a confined space by nature, one way in and out. It is not properly ventilated. Also the nature of the manhole determines the nature of hazards present and risks attached, whether or not the manhole is covered or not.
In a situation where a manhole was just opened, there are procedures to follow before it can be declared safe for entrance, in some situations they are aired out for a few days before entry.
Generally speaking; an untrained person that is not aware of these procedures, has not performed any sort of investigation of the conditions below, and does not have the appropriate gear for entry could suffer some of the following;
- Snake bite
- Attack from other reptiles and insects
- Toxic gas poisoning
- Other bodily wounds
Short notes on some risks listed above
Asphyxiation leading to death can happen very fast when the oxygen levels are gravely low and beneath the manhole it most likely is; owing to presence of other gases and poor ventilation. The other gases present are also not always detected by smell because it could be an odorless gas, the person becomes unconscious in splits on minutes and before aid of any sorts is given they are already dead. In these cases a breathing apparatus is used when entering these spaces.
It is unadvisable to go into such a space without someone close by monitoring you and other conditions.
Electrocution is also something to be mindful of, defective wires or broken cables could be the cause of this. This can be common with the manholes in homes, where people climb into the roof to check home wiring and run some other maintenance. Also due to poor lighting up there the person climbing could easily encounter such an accident.
Only a technician and someone familiar with the conditions up there should climb in and also don’t forget in the company of another person in case of emergencies.
In the case of animal attack; it is advisable to treat with pesticide or fumigation prior entry. If it is noticed some kind of animal has made this space a home, even without these signs it is very much okay to prevent encounter with these dangerous animals.
Your role in preventing accidents that involve manholes
- Educate your friends and family by sharing this article.
- When it rains heavily and the roads/streets are flooded; if the route is unfamiliar postponed that journey or wait till the ground is visible again.
- Practical actions; design and put some signs to indicate presence of such in your community
- Report broken/uncovered manhole to appropriate local government offices in person or online and tag appropriate handle. The manholes on the roads are considered public utility so the government is responsible for them.
- Refrain from entering into confined and safety critical spaces without skill and gear, call the right person for the job.