A sewer is not a place most machines are designed to work in. There is constant exposure to water, sludge, humidity and corrosive gases. Visibility can be poor, spaces can be extremely narrow, and in some environments, flammable gases may also be present.
How Sewer Robots Survive One of the Toughest Environments on Earth
A sewer is not a place most machines are designed to work in.
There is constant exposure to water, sludge, humidity and corrosive gases. Visibility can be poor, spaces can be extremely narrow, and in some environments, flammable gases may also be present.
Yet this is exactly where sanitation robots are expected to perform.
For a sewer-cleaning robot, simply making the machine waterproof is nowhere near enough. Every part of the robot, from its materials and actuators to its sensors and electrical systems, has to be designed around the environment it will enter.
That is where robotics, pneumatics and materials science come together.
What makes a sewer so difficult for a robot?
Think about what a machine normally needs to survive.
It needs protection from water. It needs reliable moving parts. It needs electronics that can continue working. It needs structural strength without becoming too heavy.
Now put that machine inside a sewer.
The robot may encounter standing water, sewage, sludge, high humidity and gases such as hydrogen sulphide and methane. Its mechanical components may be exposed to repeated impacts and corrosive conditions, while its cameras and sensors need to continue giving operators a clear view.
This changes the way the robot has to be designed.
A sanitation robot cannot be built first and protected later. The environment has to be considered from the very beginning of the engineering process.
Pneumatics: using air to create movement
One of the most important parts of any robotic system is its actuation.
The robot has to move its mechanisms, position tools and perform tasks that would otherwise require a sanitation worker to enter a confined space.
Pneumatic systems can play an important role here.
Instead of relying entirely on electrical motors, pneumatic actuators use compressed air to create controlled mechanical movement. When appropriately engineered for the application, pneumatic actuation can be useful in environments where managing electrical energy and ignition risks is an important consideration.
But choosing a pneumatic actuator is not simply about selecting one that can produce enough force.
Engineers have to look at the complete system: how much force is required, how far the actuator needs to move, how quickly it needs to respond, how often it will operate and how it will withstand the surrounding environment.
That is what turns an actuator into a reliable robotic system.
The material matters as much as the mechanism
A robot operating underground cannot afford to carry unnecessary weight.
This is one reason advanced materials such as carbon-fibre reinforced polymers, or CFRP, are valuable in robotics.
CFRP combines carbon fibres with a polymer matrix to create structures that can offer high strength and stiffness while keeping weight relatively low.
For a robotic system, that can make a real difference.
A lighter structure can reduce the load on actuators, support more efficient movement and help engineers build compact mechanisms. This becomes particularly useful when the robot has to operate inside narrow and difficult-to-access spaces.
But CFRP is not a magic material.
Its performance depends on factors such as the resin system, fibre orientation, manufacturing process, joints and the environment in which it is used. Engineers also need to consider how it interacts with other materials used in the robot.
In other words, material selection is part of the engineering strategy, not simply a choice made on a specification sheet.
Corrosion is a problem that starts quietly
In a sewer, corrosion is not always immediately visible.
Over time, moisture and corrosive substances can affect structural components, fasteners, connectors and other exposed parts. A component may continue working for a while before its performance begins to deteriorate.
That is why corrosion resistance needs to be considered across the entire robotic system.
Material selection, protective coatings, sealed connections, suitable fasteners and careful mechanical design all contribute to long-term reliability.
For sanitation robotics, durability is not about surviving one operation.
It is about being able to go back into the environment again and again.
What about methane and other hazardous gases?
This is where safety becomes even more important.
Sewer environments can contain gases such as methane, which can create potentially hazardous atmospheres under certain conditions.
A robot entering such an environment therefore needs to be designed with the possibility of ignition hazards in mind.
Depending on the application and the relevant requirements, this can involve protected electrical components, controlled energy sources, sealed systems and other explosion-protection approaches.
It is also important to remember that the term “explosion-proof” should not be treated as a blanket claim. The actual protection required depends on the environment, equipment, applicable standards and certification requirements.
For a sanitation robot, safety has to be engineered into the complete system.
Keeping water where it belongs: outside the electronics
Water is one of the most obvious challenges in sewer robotics.
But keeping water out is more complicated than sealing the main body of the robot.
There are cameras, sensors, connectors, cable entries, joints and moving components. Everyone of these can become a potential entry point.
This is where ingress protection becomes important.
Components may be designed and tested to specific IP ratings, such as IP68, depending on their intended application. These ratings provide defined levels of protection against dust and water under specified test conditions.
But protecting one component does not automatically protect the entire robot.
The complete system needs to be designed with environmental exposure in mind.
The robot still needs to see
Imagine trying to work inside a dark sewer without being able to see what is around you.
For a robot, cameras and sensors provide that visibility.
They allow operators to understand what is happening inside the manhole or sewer and control the robotic system accordingly.
But these components face the same environment as the rest of the machine. Water droplets, sludge, dirt and condensation can affect visibility. Physical impacts can damage housings or mounting systems.
So even something as simple as a camera requires careful engineering.
The goal is not just to install a camera. It is to make sure the camera can continue doing its job when the environment gets difficult.
Designing for the real world
This is perhaps the biggest difference between building a prototype and building a sanitation robot.
A robot can work perfectly in a laboratory.
But the real question is: what happens when it enters a sewer?
Does the actuator continue to perform? Can the structure handle repeated loads? Can the electronics remain protected? Can the sensors continue providing visibility? Can the robot withstand the environment over repeated operations?
These questions have to be answered before the technology can become genuinely useful.
That means bringing together mechanical engineering, materials science, pneumatics, electronics, sensing and safety engineering into one system.
From manhole to machine hole
At Genrobotics, this engineering challenge has a very clear purpose.
It is about changing how hazardous sanitation work is performed.
The Bandicoot robotic system was developed to carry out tasks inside manholes while reducing the need for sanitation workers to physically enter these hazardous confined spaces.
Behind that simple idea is a complex engineering challenge.
The robot has to move where people should not have to. It has to operate in environments that can be wet, corrosive, confined and unpredictable. And it has to do this repeatedly, reliably and safely.
That is why sanitation robotics is much more than building a machine that can move.
It is about building a machine that can survive the environment it was created to work in.
The future of sanitation is engineered
As cities look for safer and more effective ways to manage sanitation infrastructure, robotics will play an increasingly important role.
The next generation of sanitation robots will need to be lighter, stronger, smarter and more resilient. Advanced materials, better actuators, improved sensing and safety-focused engineering will all contribute to that evolution.
Because ultimately, the objective is simple.
If a job is too hazardous for a person to enter, the machine should be engineered to go there instead.
That is the idea behind taking sanitation from Manhole to Machine Hole.