Taking 'man' out of manhole: Kerala startup develops robots to clean sewage

On the morning of January 7, three men - Narayana Swamy, Mahadeva Gowda and Srinivas - entered a manhole in a posh Bengaluru locality to manually clean it. Narayana Swamy and Srinivas did not make it out alive out of the manhole and Mahadeva died on the way to the hospital.

It has been over two decades since India banned manual scavenging, but the inhuman practice continues, albeit illegally, across several parts of the country till date. Every year, hundreds of people engaged to clean manholes and septic tanks die on the job.

With an aim to stop such deaths, a Kerala startup has developed a robot to clean manholes without the need for any human having to enter the pits.

GenRobotics, a Thiruvananthapuram-based company specialising in powered exoskeletons and human controlled robotic systems, has developed "Bandicoot", a four-legged spider shaped robot that cleans manholes and attaches equipment that can clean sewage lines.

"The idea struck us when we read about manhole deaths in Kerala and Bengaluru. During our research we realised how deep a problem it was and that in the north it was also a caste problem," says Vimal, a co-founder.

"Conventionally, manholes were designed for humans to enter it if it was needed to be cleaned or unblocked. The very name 'man'-hole indicates that. We want to convert these manholes to roboholes," he adds.

GenRobotics was founded in 2015 by a group of five bright minds who wanted to create robots that could replace humans in dangerous and high-risk tasks.

Manholes get clogged primarily due to three factors - people dump things into them, or they flush things they should not down toilets, and rain water carrying debris which accumulates inside manholes.

What makes them dangerous for human beings, apart from the degrading nature of the work itself, is the presence of toxic gases that often knocks workers unconscious. It is not easy to pull a worker in such a state out of a manhole and many a time death occurs due to asphyxiation.

The existing machines to clean manholes have their own set of disadvantages, says Vimal.

"The suction machine can remove liquid waste but it is bulky and cannot be used in dry areas. Similarly a jetting machine which is used across the world is designed to clean sewer lines but not to clean manholes and take out the waste," he explains.

The Bandicoot serves the dual purpose of cleaning the manhole and attaching equipment that cleans the sewer lines.

Describing how it works, Vimal says, "The spider-shaped first removes the manhole cover via a permanent magnetic system. It then climbs down and once inside, it expands which gives it some mechanical stability. It then starts working just like a human would do. It mechanically cleans the manhole, collects the waste, then converts into its original size and comes out."

The robot is powered by pneumatics (using gas or pressurised air) since using heavy electronic equipment inside is risky as they can react with the explosive gases present in the manhole.

Vimal stresses that they do not believe in replacing human jobs with robots and have designed the user interface in a way that almost any person can operate it.

"Anyone who can operate a mobile or a toy car can operate it. We don't want them unemployed, but want them to operate the robots," he says.

GenRobotics has acquired a patent for its technology and is currently in talks with the Kerala Water Authority to provide Bandicoots to the state government.

"In the future, we hope to align our technology with Swacch Bharat and Make In India mission so that we can make the country completely manual scavenging free," he says.

(Images provided by GenRobotics)