It started with a throwaway remark. Rod Smith, a young teacher, told pupils they should “get out and see the developing world”. Great, they said. Where are we going?

Nearly a quarter of a century later, the link between Cranbrook school in Kent and Tanzania is one of the oldest in the country. It has involved hundreds of students, dozens of staff, and enough aid projects to fill a dense three-page list. It has also changed lives.

Lives like Amy Bagiant’s. Last summer Amy, 19, was all set to go to university to study English and history. But after a school expedition to Tanzania, she switched to a pre-medical course and is about to start at medical school.

“While we were out there I spent a week at a tiny village clinic doing all sorts of things you couldn’t do here,” she says. “The doctor kept saying, ‘If this person has this and this, what do you think is the matter with them?’ I’d toyed with the idea of medicine before, but on the plane home I just knew I had to do something about it.”

Thousands of miles away, in rural Tanzania, a young secondary school teacher, Emmanuel Majebele Lenga, sits in his tiny house and talks about teaching alongside Cranbrook gap year students. “I saw that they played games and made the learning enjoyable. I had learned about these techniques when I was training, but I had never seen them in action.”

Unlike most school links, the Cranbrook connection is not with another school, but a whole area. Visitors to the beautiful Tabora region, in central Tanzania, may see in one village a tiny child trotting past wearing a Cranbrook school sweatshirt and, in another, four hours’ drive away, a college building decorated with a Cranbrook-Tanzania mural.

Neither is it a typical aid project. No one talks about “empowerment” or “capacity-building”, only about friendships and practicalities.

Neema Malyeli, principal of Mwanhala folk development college, a village college which trains students in carpentry, tailoring and agriculture, says: “Cranbrook students come and sleep in our dormitories. They paint the workshop, or the hall, but then in the night they are dancing with our students, playing games.”

Back in the 1980s, Tabora was chosen by the school because a senior teacher had done Voluntary Service Overseas there, and knew of a small charity that worked in the area. The school operates under the umbrella of the charity, the Friends of Urambo and Mwanhala (FUM), but has developed its own working model. Every two years a group of students goes out to work on projects set up by their Tanzanian colleagues. Students pile into a lorry in Dar es Salaam and drive for days, often to remote villages, where they build or refurbish clinics and classrooms, or help with water or kindergarten projects. Every other year, two Tanzanian teachers or administrators come to Kent, where they visit schools, meet teachers and teach classes. In addition, money raised by Cranbrook students is used for schools, clinics, teacher housing, wells, water pumps, computers and tools.

There are also individual spin-offs. School leavers spend time there, and teachers return on private visits. Jo Taylor, head of PSHE, is doing that this summer. She led an expedition six years ago and “had some of the best experiences of my life, meeting so many wonderful people, seeing children working so hard, seeing them beat our children at sport - even though they were playing in bare feet - and seeing them out-debate our pupils, even when they were debating in their third language.” Now she can’t wait to get back to “try and help people move on with their new school. The walls of the old one are more holes than wall.”

Meanwhile, Tanzania has become a thread of Cranbrook school life. Lessons and assemblies use Tanzanian materials to discuss issues of development or HIVAids. The annual charity appeal allocates money to the link, and every school event has a stall selling wine or raffle tickets. The school raises about pound;6,000 a year for the link, half from general charity funds and half from specific fundraising.

“Continuity has been important,” says Rod Smith, who is now assistant head at Cranbrook, a grammar school with some boarding places. “Often the teacher who runs a school link moves on. But I’ve stayed here, and people at the other end have stayed part of it, too.” Central to the operation is Elias Masatu (see box, left), a senior figure in the Tabora regional government, who maintained his link work with Cranbrook and FUM even when promoted. Other link colleagues have also risen over the years, such as Deogratis Hella, now the chief executive of Nzega, a major town, and Cranbrook benefits enormously from their experience and influence. Rod Smith tells meetings of apprehensive parents: “The reason I can send your children off into the depths of Africa like this is because I know, and trust absolutely, the people who will be looking after them when they get there.”

As a result, students feel they get under the skin of Tanzanian life. “It is life-changing,” says Juliette Keyte, now a student at Manchester Metropolitan University, who went on last summer’s expedition. “We were living with the girls in the college, and we could see how upbeat and happy they were, even though they had so much less than us.”

For teachers coming the other way, there are insights, too. Neema Malyeli says: “Teachers in England don’t want to waste time. If a teacher has to go to class and teach, they go to class and teach. Here it is different, maybe because people’s wages are so low.”

“When we took 10 kids out in 1984 and installed a water pump in Mwanhala, I thought it was a one-off,” says Rod Smith. “But the kids wouldn’t let it go.” There have now been 10 expeditions, involving 120 students accompanied by 28 staff. Twenty Tanzanians have visited Cranbrook.

“It was the Tanzanians’ idea to have teachers come here. They felt it wasn’t something their students could do. They are always struck by our well-maintained buildings, and the lack of formality in the classroom,” says Rod Smith. “But we get as much as the Tanzanians out of it. Our students have such an easy life here, and when they go over there they have their eyes opened. They are living at the village level and I insist they respect Tanzanian life, so girls wear kangas (brightly coloured rectangular pieces of cloth), not shorts, and the boys wear shirts and long trousers when we go on formal visits. I think the Tanzanians like the fact that our kids do work and don’t just come as tourists, although of course it is the resources we bring that really make it worthwhile for them.”

Claudio Mzelela, the district planning officer of Urambo, lists the projects the school has helped support in his area: teachers’ houses, the refurbishment of a dispensary, college buildings, a well. “We are used to Cranbrook coming. People say, ‘Oh our friends are come again!’ Even the regional commissioner knows about Cranbrook. And we always look after them and make sure there is no problem with security.”

“They help us with teaching materials and bursaries, and we are very grateful,” says Eliza Kizinga, principal of Urambo folk development college, where Ralph Burgess, a gap year student, lived for three months this spring. “But they are also our friends. They sweep with us, walk with us, chat with us. Ralph here, he is part of our family.”

At Urambo, as in other places, a number of buildings bear the plaque “Opened by Mr Rod Smith”, who is now also secretary of FUM. But Rod Smith is modest about what the link has achieved. “I think it works because no one has any illusions that we’re going to save Tanzania. There are huge educational benefits for our children and we like to give something in return. It changes them, and it’s certainly changed me. I think I’ve become much fonder of people, and realised we don’t give each other nearly enough time.”

TOUGH BUT REWARDING

Katy Dickson and Ellie Davidson sit on a mat outside the house where they are staying in the village of Mwanhala. The sun is out, and the only sounds are birdsong and children laughing. They drink tea and admire the flourishing maize crop, which they helped to plant. Visitors drop by and conversation switches between English and Swahili. The girls have been spending part of their gap year teaching English in the local secondary school, and are well up on local gossip.

“The Cranbrook link is such a good one,” says Ellie Davidson (pictured far right). “All the time, when you’re at school, you hear things such as, ‘Oh we’ve built a well’, but it’s not until you come here that you realise what it means.”

“We’re so much more immersed because of it,” says Katy Dickson (pictured right). “We’ve been to a funeral and a wedding and a kitchen (pre-wedding) party, and you experience much better friendships because everyone knows Cranbrook. It’s the people that make it. Teaching has been hard work, but it is so rewarding. The kids are amazing; they try so hard.”

“It’s made us realise that people are the same everywhere,” says Ellie.

“When we were living in another village, Sikonge, and sitting and talking with the girls in the college, we could have been with our friends from Cranbrook. They had the same jokes, and even the same mannerisms. The girls cared about their hair and what they wore, while the boys were interested in CDs and CD players.”