Today is a day which some had feared would be chaotic. In the event, Bradford Council is predicting the biggest school reorganisation for more than three decades will almost be a text book operation.

The massive shake-up means Bradford's education service moves into a new era with 158 primary and 28 secondary schools.

And today is a far cry from last year's chaos when hundreds of children missed lessons because of delays in putting up temporary classrooms for eight and nine year olds who had to stay an extra year in their middle schools.

When reorganisation was proposed in September 1997 achievements were plummeting and there were 7,000 surplus places in Bradford's schools. The district has lagged behind much of Britain, in its system and achievements, and transition from three to two tier schooling has been fraught with trouble - including the toppling of two education chairmen in local elections.

Fierce and sometimes acrimonious battles have been fought to stop school closures, while the Council has struggled from one crisis to another - some of its own making.

So what is happening on this landmark day as the clock is turned back to the 1960s and pupils flock to traditional primary and secondary schools?

There are new heads, teachers and different surroundings, with temporary classrooms and building work which will go on in some cases for the next two years. There are teachers and staff with permanent jobs - but many others suffering the uncertainty of temporary jobs. The council says 160 are still not permanently placed and the cost could be an extra £3 million to the authority by March. But it remains adamant there will be no compulsory redundancies.

Today heads are meeting the challenges of the future with optimism and believe the new system will push up achievements, because children will now have continuity from the age of 11 to 16 or 18.

Youngsters across the district will return over the next two weeks to 210 temporary classrooms in 75 schools.

New building and alterations will take place around them over the next two years in a programme costing £171 million pounds.

Head of Beckfoot Grammar School David Horn starts the term with 17 temporary classrooms.

And while they are modern and comfortable - if not ideal - a major extension to the school is on target to be completed by next March.

His school will accommodate 1,620 pupils and about 35 teachers.

Staff will attend induction courses this week, ready for pupils to join the school on September 11. Schools have been given an extra five days leeway before pupils need to be at their desks.

Mr Horn, head for the past three years, said: "I welcome it. I think it allows secondary schools more time to work with the pupils, who previously came to us with different levels of achievement.

"Our school is making considerable progress and I think this will push things up even more.

"I am excited about it. Younger children bring life and vibrancy to a school."

At Greenhead Grammar School in Keighley, deputy head Margaret Platts finds herself working in a sprawling school with 18 temporary classrooms.

The pupils are likely to occupy them for between a year and 18 months until new, state-of-the art permanent accommodation is ready.

The school will stagger the pupils' admission from September 11 but anticipates all pupils will be back at their desks by September 14.

Greenhead has asked for an extra 48 hours on top of the five day leeway offered to all schools by the LEA.

Miss Platts said: "We wanted to make sure that everything was working and in place. I think it has been a tremendous undertaking to have so many schools open by September."

She said the school had asked for more temporary classrooms to avoid using a split site. "I think the quality of these classrooms is excellent. We have lost some hard play space but everything is going to be well worth it."

Chrissy Williams, deputy head of Belle Vue Girls' School - where ground problems have delayed the completion of a large temporary classroom - expects pupils back next week as scheduled.

She added: "I think in the long term it will be well worth it. In the short term it is hard for everyone."

But Alan Davy, head of the former Shipley C of E First School, said: "I think we have to wait until all schools are built before we can make a judgement. We will have to let it settle."

Most schools were given firm dates for all building work at the end of June and managing partner Bovis Lend Lease says all stops will be pulled out to achieve them.

But it will still mean some youngsters being taught in temporary classrooms until September 2002 - five years after the reorganisation was announced.

Secretary of the National Association of Schoolmasters and Union of Women Teachers, Ian Davey, said he welcomed the news that today's switch over was expected to go smoothly.

But he said: "I have my doubts. We still have concerns about health and safety aspects but it is difficult to find out what is happening."

Project director for Bovis Lend Lease, Tony Lenehan, has stressed that today is just the completion of the first phase of the massive programme.

He said he was confident it could meet the schedule but did not underestimate the scale of things to come.

Many schools have taken the extra days to adjust staff to the new surroundings and large numbers of them have worked during the school holidays to get premises shipshape.

Special attention is also being paid to eleven-year-olds who face the daunting task of mixing with much older children and finding their way round big buildings and temporary classrooms.

Director of Education, Diana Cavanagh, said younger children would initially be kept together with teams of teachers.

"All the pupils are expected back in the next two weeks. Bovis has brought in its great knowledge of site management which the council didn't have.

"Things are working positively. Last year at this time there was a feeling things were going in the wrong direction."

Director of marketing and communications, Owen Williams, said: "There has been a lot of concern about the schools becoming a shanty town because of temporary classrooms. In fact teachers are delighted with the standards. They aren't something which people will just have to put up with."