KOLKATA - Many of Mumbai's office workers and schoolchildren have had the privilege of enjoying fresh home-cooked food delivered to them daily by a faithful network of "dabbawalas". It is a practice that is more than a century old.

These workers - easily identifiable by their trademark white uniforms and white sidecaps, or "Gandhi caps" - make up more than just a lunchbox delivery system today.

They are a tourist attraction and a cultural icon in Mumbai - India's "Maximum City". Tourists queue up to take selfies with them and foreign business schools yearn to study their efficient working model.

But the Covid-19 pandemic cast a shadow over them and threw a spanner in the well-oiled and globally renowned dabbawala machinery.

Children have been studying online and most of the city's office workers continue to work from home since March.

The result: the decimation of the dabbawalas' customer base.

Their bicycles, which ferried lunchboxes on the final leg of their journey, rust away at Mumbai's local railway stations.

"If our customers are still at home and schools shut, who do we deliver the dabbas (lunchboxes) to?" asked Mr Subhash Talekar, the president of the Mumbai Dabbawala Association.

"Because of the pandemic, our 130-year-old effort has been reduced to zero."

To cope with this crisis, many dabbawalas returned to their villages to farm on their ancestral land. Others have taken up different professions in the city and become watchmen, rickshaw pullers or manual labourers.

The truly unlucky ones have yet to find a job eight months since their work came to a standstill.

Mr Kailash Shinde, who has worked as a dabbawala for 22 years, has been unemployed since April. He and his family, which includes three children, have survived so far mostly on his wife's earnings as a domestic helper and material assistance, such as food rations, that he and other dabbawalas receive from well-wishers in the city.

But this arrangement does not promise succour for long and the hunt for a job has become more desperate in an economy still crippled by the pandemic.

"I am willing to take up one that pays me even 10,000 rupees (S$181), but I am yet to find a job," said Mr Shinde, who earned around 5,000 rupees more every month as a dabbawala.

The pandemic's whiplash has now compelled the dabbawalas to think of alternate survival strategies.

For the first time in November, the dabbawalas took to ferrying something other than lunchboxes when the Mumbai Tiffin Box Suppliers Association (MTBSA) began delivering fresh produce and groceries.

"Because our customers currently do not require their dabbas, we are supplying them fruits, vegetables and groceries that they need daily to their homes instead," said Mr Vishnu Kaldoke, the MTBSA's spokesman. The organisation sources fresh produce from farmers' groups and sells it directly in Mumbai at competitive prices.

While there were more than 5,000 dabbawalas working in the city and its suburbs before the Covid-19 outbreak, delivering 200,000 lunchboxes daily and returning them to their homes, only around 450 are now engaged in the practice. This new arrangement to sell fresh produce and grocery items has allowed another 500 to get back on the road.

MTBSA hopes this reinvention will help retain workers so that they can quickly switch to delivering lunchboxes when normal work resumes. It is also expected to cushion dabbawalas from any threat that may arise from a post-pandemic work-from-home culture.

The origin of the dabbawalas is traced to a Parsi banker who longed for freshly home-cooked food at his office and engaged the first such individual to bring him his meals. The idea caught on quickly and an entrepreneurial Mahadeo Havaji Bachche tapped into this opportunity to start a lunch delivery service with around 100 employees.

What began with simple colour coding meant to be easily understood by illiterate dabbawalas has evolved over the years to reflect their expanded coverage. Besides colour, it today incorporates numbers and letters to indicate the collection point, the train to be taken, and the final destination of the lunchbox.

All this information is marked on the lid of the lunchbox, which can change hands as many as six times during its daily journey and even travel over 50km one way. Slip-ups are, however, rare. A 2010 study by the Harvard Business School found they make fewer than 3.4 mistakes per million deliveries and accorded the dabbawalas a coveted "Six Sigma" rating.

Laurels such as this have ensured they remain an iconic Mumbai institution, one that has weathered cultural shifts such as the growing popularity of takeaway lunches and online food delivery services.

Banking on this illustrious track record, the dabbawalas are now praying that the pandemic recedes, allowing the city to pick up its frenetic pace again and them to win back their lunchboxes.

"We feel that as long as a mother's love remains for her son, a sister's love for her brother, a wife's love for her husband, as long as the family structure is retained in Mumbai, food will be cooked at home and sent out," said Mr Talekar.

And until that changes, he added, dabbawalas will remain at the service of Mumbaikars. "I am hopeful. It is hope that sustains the world."