They say teaching is getting like the police force - everyone expects to retire at 50. “There’s a totally different feeling about the career now, ” says one local authority source. “At one time people aimed to get as near to the full 40 years’ service as they could. Now they think, ‘I’ll get to 50 and then see what I can arrange about my retirement’.”

David Hart, general secretary of the National Association of Head Teachers, has noticed the same trend. “We are reaching a stage where people are looking at a career span which resembles the police, but without the benefit of the police pension,” he says, observing that the police are guaranteed full-pension rights after 30 years’ service.

This relatively new phenomenon in teaching looks as though it is here to stay. Indeed, professional associations, as well as older teachers and heads, are already advising younger professionals on how to plan for early retirement.

The loss of experienced heads is particularly significant, and raises two important questions. First, how did headship become the kind of work that left the middle-aged queuing to get out? And second, does it matter; are we just seeing a natural culling of the scarred and worn-out elders of the pack?

There is a simple answer to the first question: as time passes, professionals lose their edge. In the 1970s, it was common for teachers as young as 30 to be appointed to headships. If those individuals have been in the same jobs for 20 years, that is arguably more than enough, for the schools as well as the heads. Tim Peskett fits this profile. He retired this year, aged 50, as head of Weedon Bec Primary in Northamptonshire, having been in the post for 20 years. “That poses certain problems,” he admits. “After a time I couldn’t get the buzz, simply because of longevity.” John Paley, who has also just retired at 50, became a head in Warwickshire in 1977. He believes promotion came too soon. “Looking back, perhaps it was too young, but that’s how things were then, ” he says.

So where does a tired head go for a new challenge? The traditional openings beyond headship have gradually closed up as authorities have slimmed down their advisory and management services. Nor, as David Hart points out, does education offer the opportunities that are open to a manager in, say, Marks and Spencer - to be used as a trouble-shooter running bigger or more complex branches of the business. “We’ve never had a system where we could move a successful head to a school that needed fresh blood. We have a national service which is administered by 25,000 individual heads and governing bodies,” says Hart.

So it is that many of our schools are being led by people who are finding it increasingly difficult to reinvent themselves. For David North, of Whitmore Junior School in Basildon - still carrying on, although at 54 he has been a head for 25 years - the effort needed to restart each school year becomes ever greater. “Sometimes I feel I’ve given so much I’ve been bled dry and I find it harder to go back in September,” he says. “At the moment, though, it’s OK - once I get there.”

On top of this, of course, is the fact that the work itself has become significantly harder. The latest evidence from the teachers’ pay review body shows that heads and deputies are commonly working around 60 hours a week, and, says David Hart, “it does tell after a while”. John Paley has experienced the gradual acceleration of education reform: “Such a lot has come in that I didn’t feel really in control of - there are more and more external pressures. ”

This is not, however, just a complaint about legislation and reform. Much of what the Government has done has been welcomed. The resentment comes with the realisation that it all has to be done on a shoestring, from existing budgets. Hart cites special-needs legislation as a case in point, calling it “a well-thought-out, welcome reform which has been under-resourced”. Or, as a primary head put it on a World in Action investigation of special needs a few weeks ago: “It’s Rolls-Royce legislation with methylated spirit in the tank.”

Rising class sizes and a perceived fall in standards of behaviour are influential too. “I do think,” says Hart, “that the very long hours, combined with excessively large classes and an increasing number of disruptive or even violent pupils, are all having an impact on senior staff.”

Many heads, though, would be willing to go on doing more work on shrinking budgets were it not for what may be the most powerful disincentive of all: what they see as a constant and pernicious stream of criticism from outside. Every head feels this, though they deal with it in different ways.

Bernard Barker, in the process of leaving the headship of Stanground College in Peterborough, feels strongly about the criticism. “There’s an annual cycle, ” he says. “The A-levels are no good, the kids are no good, universities are no good, key stage 2 results are a shock-horror story. And along come critics like Melanie Phillips to tell us we are scandalous people who have betrayed a generation. The culture of blame is pervasive, and it’s a very nasty little atmosphere.”

David Hart is equally adamant that the incessant media offensive demoralises its targets. Referring to the reporting in February of the key stage 2 results (“Banner headlines telling the world that schools were failing the majority of children - a false statement for which the Government was wholly responsible”) he says: “Teaching is a job done by people who see it as a vocation. They are devoted to their pupils, and they do not like to be told by the media something which is demonstrably untrue.”

Different heads have their own ways of coping. David North says that for some time he’s taken no notice of the criticism. “People ask me whether I’ve seen this or that television programme, and I never have, because I’d get quite uptight. And if you shout at the TV you’re not far from breakdown, are you?” For North, it is a matter of knowing what is possible. “I can’t change things nationally. In our own school I can change things, and what we do is greatly appreciated by our own community. That gives us considerable strength and confidence to meet an experience such as OFSTED, for example.”

Being confident that what you are doing is right and effective is one of the key factors in maintaining a headteacher’s morale - though it is not the only one. Bernard Barker does not lack confidence; for him, the problem is the disparity between teachers’ achievements and the lack of recognition of them from above.

Sylvia West, of Impington Village College in Cambridge, speaks of the need for reflection and study. “I did a PhD during headship, and I found that it keeps alive an overview of the context in which we operate,” she says. And she is very clear and confident about the purpose of her non-selective community college: “All schools should be built on integrative principles, and these community schools are like that.”

Maureen Cruickshank, of Beauchamp College in Leicester, also chooses to work in an authority that pioneered non-selective schooling. She plans still to be in post beyond the millenium, “when I’ll be nearly 60”. Beauchamp is a 14-18 upper school that has grown, driven by parental choice, by a third in three years and now has 1,600 pupils, 700 of them in the sixth form. “At the moment I find it enormously challenging and enjoyable,” says Cruickshank. “The liberation of LMS has made it so much better.”

Cruickshank, of course, is managing expansion; each year she has more students, more teachers, and thus a growing budget. She readily admits that she would see her job very differently if she was having to make people redundant.

Does it matter that the old hands are departing? After all, David Hart is at pains to emphasise that there are “talented heads and deputies coming forward, brought up in the white heat of educational reform”. And retiring headteachers often express admiration for their keen successors; indeed, often it is only because they do not want to dampen this enthusiasm that many older heads hold back on their reasons for resigning.

But seniority and experience bring distinct advantages. David North has, over the years, won the support of a difficult community. And in Coventry this summer a head spoke regretfully to me of the early retirement of a much respected colleague - “In many ways the senior primary head among us, someone we turned to for advice.”

Of course, in many cases the experience is not being totally lost. Bernard Barker will build a new academic career, Tim Peskett has already started his, and others often go on to consultancy and inspection. As someone who himself left headship at 52, though, I feel that the profession is enriched by the continuing service of people such as David North - weary at times, devoted to the children, respected by the parents (many of whom were his pupils too), deliberately avoiding the great education debate, and conscious all the time of the inherent dangers of growing old in the job. (Significantly, I met him on a two-day course for primary heads on the latest developments in information-handling.) “Sometimes I think I’m the greatest agent against change in the school,” he says. “After all, anything that we decide to change is likely to have been instituted by me. So when they decide to reorganise the entrance hall, I find myself thinking, ‘Hang on! I did that! I put that fish tank in!’ We do have to be aware that we don’t sit and reminisce about the good old days: the only difference between being in a rut and being in the grave is the depth of the hole.”

HEADS’ PENSION ARRANGEMENTS

Heads’ pension arrangements are the same as for other teachers.

The maximum income (after 40 years) is half the final salary and a one-off, tax-free sum of about three times the annual pension. But teachers often start well into their twenties, and many have breaks along the way, so few achieve 40 years.

Early retirement

A teacher of 50 or more can ask the employers (governors andor local authority) for early retirement. If it is granted, the teacher draws whatever pension has been earned up to the agreed leaving date.

Enhancement

Where it suits them, the employers can boost a retiring teacher’s pension by adding notional years of service. In cases of reorganisation or school closure,they may add up to 10 years.The evidence is, though, that heads not involved in reorganisation are being given little or no enhancement.

Ill-health

A teacher who is declared medically unfit will be granted some enhancement, depending on age and length of service. Six years is typical for someone in their early fifties.

Buying extra years

Many teachers now spend extra money on their pension contributions with a view to early retirement. The earlier you start the better.

Who can afford to retire?

Heads’ salaries range from Pounds 25,000 to Pounds 55,000 and pensions vary in proportion. A 50-year-old head of a village school with some mortgage still outstanding and a daughter at university may well feel unable to retire - whatever the pressures - on a non-enhanced pension of less than Pounds 10,000 a year.The head of a large comprehensive whose house is paid for and children grown up might feel differently.