Dangers of using manhole steps in poor conditions
This article has been extracted from the website www.DrainDomain.com, which offers a multitude of free advice related to repair, cleaning and maintenance of existing systems of supply, sanitation and drainage, both individual and urban.
This post exemplifies in a concise and direct way what are the dangers and risks that exist at the time of entering a well or inspection chamber, as well as the access systems that we will find inside, which range from those already known steel/ iron steps or even bricks, up to the stairs for more modern wells that exist today such as polypropylene manhole steps:
Access to confined spaces
In the first place, manholes and inspection chambers are dangerous places that only authorized personnel should have access to, who have the knowledge and the necessary security means to carry out the relevant maintenance work inside the well. Noted that in the vast majority of inspection chambers, access is made once or twice a year for reasons of routine maintenance, but sometimes there are wells that are not visited for years, only when an incident occurs.
Once we lifted the sewer cover and looked inside, we usually found fixed ladders or manhole steps, which were probably placed at the time when the sanitation system was built, so each step inside the well is a leap of faith.
Which ladders are the most common in confined spaces?
Manhole Step Irons
Step irons are the steel or cast iron rings built into the chamber wall so that you can get in and out of the chamber, however given the environment they are in it is little wonder that the older irons corrode and snap over the years. This is why inspection chambers should only be entered with the correct safety equipment provided including a fall arrest winch and line.
You do not know when the chamber was last entered so you should not trust that the step iron will take your weight, a quick visual survey of the rungs along with a good swift stamp onto each step before you put your full weight onto it is always a good idea.
Sods law says that when you will find the only rotten step iron in the chamber with your foot, your chin will find every solid step iron on the way down to the bottom of the chamber, Guaranteed !
If the step iron is solid and capable of taking your full body weight there is always the chance that the mortar between the bricks has perished, this will be the step iron you are holding onto when you are leaning back and before you know it you will be plummeting to the base of the chamber with a perfectly sound step iron in your hand.
Other unwritten rules that apply to chamber access is that the bricklayer who built that particular chamber had the longest legs in the country, so you being of average height are left swinging your lower leg around looking for the next step with your other knee under your chin, or just as bad the brickie bless him forgot how the sequence of steps should go so you find yourself with two feet on one step trying to traverse half way down a chamber.
This bricklayer was not only 7ft 6inch tall but he also had the physique of a racing snake, so you often find yourself in a 600mm square access chamber trying to bend your knees to reach the next step, so again it is safer and easier to use a fall arrest winch at all times.
Alternatives to step irons were pieces of angle iron of thin strips or metal set into the corners of the chamber, again prone to snapping or coming out of the wall completely, another favorite is to leave half bricks out of the wall creating a built in ladder, again very tricky to get a decent hand grip on in damp and dark conditions.
Modern Manhole Steps / Step Irons & Access Ladders
In recent years, precast concrete manholes have been much more popular than those built with brick. The fixed manhole steps have also evolved, incorporating the steel rod that was previously bare, a layer of plastic that protects it from rust and moisture in the well. The lashing in harpooned form of these polypropylene manhole steps ensures that, if the installation has been done correctly, it is very difficult to pull it out the concrete wall.
However, the first manhole steps at the entrance to the well remained difficult. Many times, the operator had to step blindly with the consequent danger of slip or fall. To fix it, some opted wrongly to install a polypropylene manhole step on the surface to achieve a minimum grip. Practice that is prohibited and we highly disapprove it.
In 2017 from IVERNA we presented our stainless-steel handhold bar at the International Water Trade Fair (SMAGUA 2017). A retractable bar installed either on the first step irons or on the wall of the manhole that rises up to 1 meter above it, allowing a firm grip to enter the confined space much more safely.
In IVERNA we are continuously innovating to reduce risks in vertical works. If you want to know more about our complete product portfolio, check out our website or call us for advice!