Field Notes Society

The first robots clean India's sewers, 25 years after manual scavenging was outlawed

 Sateesh S. Nair operates the Bandicoot in Thiruvananthapuram

Sateesh S. Nair operates the Bandicoot in Thiruvananthapuram

In February this year, in Thiruvananthapuram, with at least a dozen cameras on him, Sateesh S. Nair tentatively punched a series of red buttons on a large arachnidian machine — India’s first ‘manhole cleaning robot’ called Bandicoot. Nine engineers, all in their early 20s, the creators of the robot, looked on a little nervously: this was going to be the first public demonstration of Bandicoot, still very much a beta version. Nair’s eyes shifted between the screen on the machine and a manhole a few feet away as the robot juddered to life. A spindly pneumatic arm lunged out and clamped open the manhole lid and four aluminium legs plunged into the abyss. A loudspeaker blared music, a scooper ‘hand’ emerged from the bowels with a sizeable heap of sludge and deposited it into a bucket.

Nair, wearing a gleaming yellow helmet, matching gloves, a road safety jacket and new boots, smiled for the cameras. But this time last year, a photo in a Malayalam daily had captured Nair immersed chin-deep in sewage, a stick in hand, cleaning a manhole in Thiruvananthapuram.

It is what Y. Manikandan, 32, still does in Chennai. When he sets out to work in the morning, carrying a plastic bucket, a stick and shovel, his wife Muniammal is never quite sure he’s going to make it back home safe. There have been days when he has come close to losing consciousness from the toxic fumes; others, when he has feared he’ll drown in the turgid water.

And when he does return, it’s tough shaking off the shadow of the day’s work: his limbs are covered in rashes, and he barely eats because the stench of excreta doesn’t go away even after he has bathed “with Dettol”, says Muniammal.

 Y. Manikandan, a manual scavenger in Chennai

Y. Manikandan, a manual scavenger in Chennai

Manikandan, a Dalit, is employed by a contractor to clean sewers and septic tanks in Chennai’s Vyasarpadi area for ₹360 a day. He lowers himself into manholes, sometimes holding on to a co-worker’s hand so he doesn’t go under. He uses a metal rod and his bare hands to dislodge the debris that clogs the lines: sanitary pads, e-waste, tree roots, human hair. And he must haul himself up before the carbon monoxide and hydrogen sulphide from the waste water knock him out.

He describes this daily drill as “ abayakaramana velai ” (dangerous work). “We risk our lives every day,” he says. Between 2014 and 2016, as many as 1,268 men died while cleaning sewers, according to Safai Karmachari Andolan (SKA), an organisation that works to eradicate manual scavenging.

Rooted in caste

It has been 25 years since manual scavenging — a practice rooted in the caste system and carried out largely by Dalits — was outlawed, and five years since the Prohibition of Employment as Manual Scavengers and Their Rehabilitation Act, 2013 stated that it is the ‘duty of local authorities and other agencies to use modern technology for cleaning of sewers’. But it is only now, and with no help from the central government, that the first technological innovations are emerging.

Vimal Govind, the CEO of the Genrobotics team that created Bandicoot, had just finished designing a ‘power exoskeleton’ — inspired by James Cameron’s Avatar — a 14-ft machine that mimics human movements, when the Kerala government approached him to design a sewer-cleaning robot.

With funds from the Kerala Startup Mission, and several months of intensive research, they came up with a ‘spider robot’ that can stretch its legs and immerse a camera into the manhole so that the operator can guide its automated arm to shovel debris or direct a water jet into sewer lines to unclog them.

There were R&D problems: the team discovered, for instance, that manholes are not consistent in shape or size: “some are square, some are round; some cylindrical, some conical, their diameters vary,” says Govind. Bandicoot today is no longer the odd mangle of tubes and wires it started as. It has been simplified in terms of user interface, it is more compact and made of a lighter carbon fibre. And outside Kerala, the robot has been acquired in Tamil Nadu’s Kumbakonam town and in Anantapur district in Andhra Pradesh.

Tech challenge

If Bandicoot weighs 60 kg, Sewer Croc can be lifted with one hand — but it is fierce. In June this year, a group of 10 senior engineers — aerospace, mechanical, electronic, robotics, mechatronics and software — demonstrated the little robot they had created pooling in their personal resources, at the Hyderabad Metropolitan Water Supply and Sewerage Board (HMWSSB).

Sewer Croc, named after its faintly reptilian look, is less than half a metre long, fitted with powerful blades, and spring-loaded wheels that let it manoeuvre narrow sewage pipes. It comes with a rover camera that rotates 360 degrees to locate debris. The machine, made of corrosion-resistant steel, is powered by a high-velocity water jet.

The Sewer Croc team came together last year following a spate of deaths of manual scavengers, and after a meeting with SKA’s national convenor, Bezwada Wilson. “We first took time to understand the reason for the alarming number of deaths and to see where exactly we can come up with technology that can help save lives,” says Germiya Ongolu, who retired as Deputy General Manager (Design), HAL, and leads the Bengaluru-based Ajanta Technologies.

Sewer Croc was not their first innovation. They also created a device that can be attached to a manhole lid to read the concentration of poisonous gases and sound an alarm if the levels are high.

HMWSSB is in the process of placing orders for 28 Sewer Croc machines, now being fine-tuned to fit pipes of different dimensions. Later this month, the machine will be showcased at a sanitation technology forum organised by SKA in Delhi, along with 14 other innovations developed across the country to replace manual scavenging.

Meanwhile, the urban affairs ministry has posed a ‘technology challenge’ to individuals, companies, institutes and others to identify solutions to clean sewers and septic tanks. The winners are to be rewarded on October 2 at the Mahatma Gandhi International Sanitation Convention in Delhi. But this, says Bezwada Wilson, is too little, too late. “When we have such a huge problem that’s putting thousands of lives at risk, the government seems to have transferred the responsibility of finding a solution to individuals and organisations.”

The fact that such little investment has been made on innovations for sewage cleaning in a country that has just announced its first manned space mission reveals “the structure of the caste mindset that assumes a certain section of people are born to clean,” he says.

A slew of interventions are needed to end manual scavenging, Wilson continues, including better methods of sanitation in the railways — where one of the largest sections of manual scavengers are employed to clean tracks — and more efficient machines to empty septic tanks. “It is not going to be possible to eliminate manual scavenging unless we create the right technologies,” he says.

divya.gandhi@thehindu.co.in


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Printable version | Sep 10, 2022 2:51:12 am | https://www.thehindu.com/society/the-first-robots-clean-indias-sewers-25-years-after-manual-scavenging-was-outlawed/article24841833.ece