South Africa's Phelophepa train draws a crowd wherever it goes.
The sound of the lumbering 19-car clinic-on-rails signals the arrival of badly needed free healthcare for thousands of South Africans as it tours the country.
"When you arrive, people are always ready, there will be kids performing," said train manager Anna Mokwena, a nurse.
At a stop this week in Pienaarsrivier, a town in South Africa's impoverished Limpopo province, dozens of elderly patients alongside women clutching children flocked to take advantage of the service.
"We are so happy. I got two pairs of spectacles and now I'm going to see the doctor for a checkup," said 60-year-old Janette Rakgetse from nearby Hammanskraal.
"I've saved a lot of money. We arrived at 5:00 am to beat the queue. We are a group of grannies who organised ourselves to come here."
The train clinic will spend a fortnight alongside Pienaarsrivier's neat red-brick station, 55 kilometres (35 miles) north of the capital, Pretoria, before travelling 500 kilometres to Ladysmith in the country's east.
It will provide access to general medicine, dentistry, psychology services, a fully stocked pharmacy and an eye clinic.
Final-year medical students at universities across South Africa help up to 400 patients a day.
They will typically spend a fortnight onboard before swapping with a fresh team of interns.
Run by Transnet, the state-owned rail logistics operator, the train has rotating crews of students who work with a permanent team.
"We help people to see -- then they can move around freely. The train gives people hope," said fourth-year trainee optician Percy Makgwane, 22, a student at the University of Limpopo.
"I'd love to work here permanently."
In 2014 Transnet supplemented the first Phelophepa train, which started as a modest three-coach setup in 1994 but now has 19 carriages as well, with a second one at a cost of 80 million rand ($6.2 million, 5.8 million euros) for the coaches alone.
The name means "Good, clean health" in South Africa's Tswana and Sotho dialects.
- 'Trains of hope' -
More than 24 million patients have been treated by the services, dubbed the "trains of hope", since their launch in 1994, making it the world's largest mobile clinic.
Patients are typically charged 30 rand ($2.30) for a pair of glasses, 10 rand for dental work and five rand for prescription medicines.
"The charges give the patients a sense of participation but also help to alleviate poverty," said Mokwena, the train manager.
"We are just alleviating the situation, we are not taking over from hospitals. We are just the second hand helping the first."
The train also creates jobs wherever it stops, employing a small army of cleaners, porters and security officers for the duration of its stay.
South Africa is facing a dire shortage of doctors and medical professionals, with the Limpopo province one of the worst affected.
"It's great for the patients because they don't have services like these," said Mizo Zulu, a pharmacist.
Each train has 22 permanent employees, 16 security contractors and around 40 students onboard at any one time.
The immaculate white carriages emblazoned with the word Phelophepa are pulled by a locomotive powered by either electricity or diesel, depending on where it is in the country.
The two trains spend nine months a year criss-crossing the country, reaching some of South Africa's most neglected communities.
The timetable is publicised ahead of each stop with an advertising blitz that includes radio bulletins and ads in local newspapers alongside poster campaigns and leaflets.
The two trains attempt to visit nearly every region of the country once every two years.
"I wanted to see this train with my own eyes," said Rakgetse, the elderly patient. "I'll send other people to come."
And there could be a new Phelophepa just down the line. Transnet has submitted a proposal for a third clinic in light of the runaway success of the first two.