The collective army of Dhobi-wallahs (washermen/women) have kept the fabrics of India clean and neatly folded for centuries. Soaking and smashing laundry in streams, rivers, lakes and throughout the labyrinth of Dhobi Ghats from north to south and across the Indian sub-continent, they have consistently played a major part in everyday domestic and commercial life.

Estimates reckon that they number around 400,000, with a market value of over US$ 250,000 million. These figures highlight the precarious economic worth of such a trade. It is a genuinely physical and hugely time-consuming job which demands dedication and a high work ethic from these self-employed traders to make a worthwhile living.

That said, it has always been an honourable living, greatly admired over time. For example, I have childhood memories (from living in Tamil Nadu) of the significance, and upping of noise levels throughout the house, when the Dhobi came calling.

Dhobi-wallahs are a greatly appreciated caste, admired by travellers as much as locals for their ability to scrub the living daylights out of laundry soiled in India’s punishing heat. Many a time a pair of my well-travelled trousers, or unimaginably dirty shirts, have been return better than new. Crisply clean and ironed to military standards.

So, when I returned to India recently with Richard Crombie to interview, record and film a cross-section of local Keralan society, I was also keen to step back into the world of the Dhobis. Taken at the Dhobi-ghats in Cochin, these photos show how well organised their washing, drying and ironing practices are.

Armed with tin-scoops of detergent, smooth concrete washing surfaces, Popeye-stamina, knee-deep water baths and ultimately the midday sunshine, they take dirty clothes and give them the mother of all ‘rinses’, before finally drying and ironing the oh-so-clean garments with a selection of coal-fired and electrical irons.

It’s an efficient and well-honed process that takes place to the backdrop of more chatter and noise than a flock of hungry seagulls could offer. The babble is as fierce as the pounding of linen on wet, time-smoothed concrete.

That said, like so many traditional practices in India, this manual service is under pressure, and faces an uncertain future due to increased mechanisation in Indian society. Although under threat from the existence of more and more domestic washing machines, they do still ply their trade, serving a significant number of hotels and restaurants, as well as hospitals, railways, the civil service and many local households.