It was sure to happen. Laid inelegantly on the grass, like the petrified victims of a terrible road accident, were three female forms doomed never to fulfil their promise, casualties of the early enthusiasm of five lower-sixth girls that melted with the spring.

“I suppose we should have been more careful about who we picked, and it’s disappointing, but we’ll manage without them,” says a philosophical Olwyn Jones, head of art at Parliament Hill School, Highgate, in north London. For even these concrete failures, which were to have been three of four caryatids supporting a glass dome, underline the successes of Parliament Hill’s artist-in-residence enterprise.

Looking down the slope of what is becoming the school’s sculpture park stands a ferocious steel and aluminium warrior queen, a tribute to the victory of creative inspiration over adolescent prejudice. It was made by one of only two boys among the 125 15 to 17-year-olds in the scheme, the theme of which is the achievements of women.

“I had some problems with this one, too,” says Ms Jones as we gaze at the massive steel torso. “There was a resistance to the idea of what he (the sculptor) saw as a feminist statement, and it even came to interviews with parents. But he came over by realising that it didn’t really matter what the theme was; it was working to a firm brief, and it was working with metal, in his case, and learning how to rivet, how to solder, how metals work together, how to balance, and I think it’s a great triumph for him.” The warrior queen looks down a sloping, tree-spattered lawn on to a further seven pieces: one tree is festooned with embroidered medallions; another has a girl-sized nymph lolling in its boughs; there are seats moulded in concrete and tessellated; and a trail of 73 large mosaic discs curls through the grass. In the middle of the park is a piece by the school’s sculptor-in-residence herself, Hannah Littlejones.

“I really enjoy making large-scale sculptures in schools because it’s a chance to do something completely out of the ordinary, and pupils really respond to it,” says Ms Littlejones. “They get a great sense of pride and achievement and it generates a lot of excitement in the school. What I often find is that students have conceptually developed a lot, but they don’t have much experience of hands-on working, so that almost every process is new to them.”

Sculpture is expensive, labour-intensive and time-consuming; when the Parliament Hill project formally opens on July 14 it will have been under construction for seven months and required evening and Saturday work from the three staff members involved and most of the students. The residency was funded by Camden Artists in Education - which has backed numerous other projects involving music, dance and sculpture since it was set up in 1994 by Camden council’s arts and tourism department, with money from the London Arts Board - but the materials had to be paid for by the school.

But it was worth the time, effort and expense. Indeed, Channel 4 was so impressed by the project that the sculptures are to feature in C4‘s Schools at Work series in September.

“Sculpture as an experience isn’t often available,” says Olwyn Jones, who is co-ordinator of the project, “and it also provided an opportunity to work in a cross-curricular fashion - design, technology and the arts together.”

If one or two of the participants fell by the wayside, most stuck with it. “I don’t know if I’d have gone in for it if I’d known what would be involved, ” says 17-year-old Eleanor Ratliff, one of a team of four that has created “The Three Graces” out of wire mesh, plaster, fabric and paint. “It’s meant a lot of working after school and on Saturdays since January, and sometimes it’s been very frustrating when it hasn’t gone quite right,” says Eleanor. “But now we’re here at this point, well, it’s fantastic.”

Eleanor and her group liked the theme of “The Three Graces” because of its references to motherhood, sensuality and wisdom, so the project has taken them into the classics, history and theology as well as the creative disciplines.

Camden’s arts residencies are co-ordinated by Sita Brahmachari. “Sculpture and the possibilities of sculpture seems to be a weak area in the curriculum, ” she says, “and it goes a bit beyond the more customary murals and stained glass, so we’ve been keen to encourage schools to go for it. But it is a big commitment for them, which can be understandably off-putting.”

However, sculpture in schools is growing in popularity, as a national survey being carried out by the art and design department of London University is expected to show. Research by two teams of academics in Providence, Rhode Island, has already shown that general learning is significantly improved by early involvement in art - the so-called “Mozart effect” - and sculpture is seen as particularly broadening of young minds, according to Martin Turner of the West Midlands Regional Arts Board. “There is a lot of data about this, and now the practical experience appears to confirm it,” Mr Turner says.

Sculpture will also shortly receive a significant boost from a three-year scheme called Forms of Experience being organised by the three Tate Galleries - in London, Liverpool and St Ives - and funded to the tune of Pounds 60, 000 by the Henry Moore Foundation. The scheme is still at the planning stage, says the Tate’s head of schools and community work, Colin Grigg, and it is unclear whether the sculptors involved will be resident only at each gallery and take workshops at schools, or resident in the schools themselves. But the aim is clear: “We want to do three things with it,” Grigg says. “It’s a way of integrating the three sites, sharing the programme, which effectively means covering the whole country; its emphasis is on producing learning resources rather than just single projects, so there is longer-term benefit; and it brings an emphasis on sculpture when most of the work in outreach has been about painting.”

What is unusual about the Parliament Hill School project is that it has received no money from the National Lottery. Liz Reiss, of the Arts Council of England, links the growth of sculpture projects in schools directly with the lottery. “In the past two years I have assessed probably dozens of school sculpture projects, mostly involving artists-in-residence, all the direct result of the availability of lottery funding,” she says.

With the help of West Midlands Arts, Belle Vue Primary at Wordley in Dudley took on a project that would have been impossible without the lottery. Last year the school was awarded Pounds 84,000 by the Arts Council’s lottery panel for a Pounds 100,000 sculpture trail, which opened on June 12. The project took two years to complete.

much of the rest of the funding had to be raised by the children themselves; they also found themselves involved in landscaping the terrain, which swallowed Pounds 30,000 of the budget. The project has a resonance beyond the school, in that it helps to give some character to a bland neighbourhood.

Belle Vue was surrounded by a piece of rather depressing land which deputy head Peter Brownjohn was keen to transform, for the better enjoyment of both pupils and residents. After planning sessions with West Midlands Arts, the result was not one artist-in-residence but 11, each working directly with the pupils to produce a piece of work, so that the school is now surrounded by a landscaped sculpture trail punctuated by 11 pieces, many of them bigger than adults.

Some of the pieces dovetail with coursework - for instance, the whale’s tail, on which the pupils stuck hundreds of pieces of coloured tile, ties in with a curriculum project on whales - and they are intended to be played with, in and on. They are accessible by wheelchair, and there is even an audio guide for the visually impaired. “The whole school has been part of this, and although it has been exhausting I think it has been the most worthwhile project I have ever been involved in,” says Peter Brownjohn.

But perhaps the last word should go to one of his pupils who, asked to comment on the experience, wrote: “Sculpture, I think, is a long piece of joined happiness.”

Camden Arts and Tourism: 0171 267 1259. West Midlands Arts: 0121 624 3200. Regional Arts Boards will provide advice on sculpture residencies