Is this the end of the line?

Ah, the Tizer, the anoraks, the illicit thrill of 'shed-bashing' - as a boy, John Lichfield was obsessed with trainspotting. Now, his hobby may be banned, on the bizarre grounds that it poses a terrorist threat. But they can't take away his memories...

The time is just after 12.30pm on any weekday during the school term in 1959 or 1960. The place is Macclesfield, Cheshire, then still a red-brick mill town, not the posh suburb of Manchester that it was fated to become.

The time is just after 12.30pm on any weekday during the school term in 1959 or 1960. The place is Macclesfield, Cheshire, then still a red-brick mill town, not the posh suburb of Manchester that it was fated to become.

I have a choice to make. Do I queue for my school lunch (vinegar-soaked chips, baked beans and Spam, followed by sago pudding with a dollop of jam). Or should I skip the feast, run across the school field - which, to a 10-year-old, looked as big as Hyde Park - and keep my appointment with Charles Dickens? Or possibly Byron or Tennyson or Lord Kitchener?

Most days I skipped lunch. There were always 30 or 40 other boys waiting by the fence at the far end of the field. In my memory, it was always foggy. Two or three of us had to tunnel through a hole in the school fence (breaking a school rule) and climb over the railway fence (breaking the law) to make sure that we missed nothing important. We need not have bothered.

The Comet, the misnamed, morning express train from London Euston to Manchester London Road - which ambled steamily from the tunnel at the north end of Macclesfield (Hibel Road) station at this location, at vaguely this time - was always a miserable disappointment. It was invariably pulled by one of the local (Manchester, Longsight) engines, which were as familiar to us as Spam and sago pudding.

We missed lunch in the passionate hope that the Comet might be hauled by something more glamorous than Byron: something which came from a faraway place of which Macclesfield schoolboys could only dream. Camden, for example.

Yes, I confess it. I was a trainspotter.

From the age of eight until the age of 14, with a couple of relapses after that, I was one of those reviled creatures who inhabit the twilight zone at the end of station platforms. I even, for a while, had an anorak with badges sewn on it and a red hat with a white bobble on the top. I had little books with lists of figures underlined in red or blue, and dog-eared notebooks full of numbers.

I still have shelves of railway books, and still study, with enormous pleasure, my copy of the British Railways (Western Region) timetable for the summer of 1957. Even now, when I travel by train from my home in Paris to London, as soon as we pass through the Channel Tunnel, I feel like an ex-smoker who has not quite been cured - an urge to reach for a pen and paper.

Lunacy? Amiable eccentricity? Such is the intensity of the propaganda war against trainspotters these days (how long before the News of the World has a name-and-shame campaign, and demands a national register?) that I have generally played along with the mockery.

Now, the joke is over. The very existence of my hobby - or ex-hobby - is threatened. Several of Britain's new railway companies, and a company that runs a group of large stations, are threatening to ban trainspotting altogether. At the very least, they say, they may require trainspotters to seek permission, in writing, to stand on platforms. Why? What harm can trainspotters do? There seem to be so few of them these days. But apparently, the railway companies (some, not all) fear that trainspotters could be terrorists in disguise.

What a typical triumph for the railway-hating non-railwaymen who now run Britain's railways. They have identified the last few British people who still love railways, and they want to ban them.

Their silliness has been the occasion for another cloudburst of mockery of trainspotting in the press. Let the mockery cease. Trainspotting was - and doubtless still is - an admirable occupation. It bred a sense of adventure, courage, comradeship, accuracy, honesty, patience, endurance, wiliness, and a lifelong love of Tizer and cheese sandwiches.

Bans on trainspotters are not entirely new. In the 1950s, trainspotting became such a craze that the number of boys on the station ends (never any girls) became dangerous. Trainspotting was banned at some of the great shrines of the hobby, even at the greatest shrine of them all: Crewe, the vast six-way junction in the middle of the Cheshire plain, where I spent many hours of my childhood.

At Tamworth, in Staffordshire, where two main lines crossed, the ejected trainspotters colonised the nearby farmland like rooks driven from their roosts swarming on to the fields. Over 500 boys from all over the country might gather there on a summer Saturday. Unlike today's non-railway railwaymen, the railwaymen of the 1950s and early 1960s enforced their partial trainspotting ban reluctantly and patchily. We always felt that most of them were on our side (except the locomotive firemen who would cover up their engines' numbers with rags as they raced past the Tamworth field).

What on earth, people sometimes ask, is the interest in standing on the ends of platforms, or in fields, collecting locomotive numbers? The question misses the point.

The locomotive did not just have numbers and we did not stay on the platforms. We pursued the engines into their homes, sneaking, quite illegally, around locomotive sheds. This practise - "shed-bashing" - was the real excitement of trainspotting. It provided the trainspotters' heroin rush that makes the title of the movie Trainspotting almost appropriate.

Even at a miraculous spot such as Crewe, if you stayed on the platform, you might collect not more than 20 numbers in an hour. (That's where the patience and endurance comes in.) If you got into Crewe North and Crewe South sheds, you might get 300 numbers in a hour. Wow.

Shed-bashing was, of course, quite illegal. To get into Crewe North, you had to cross a private footbridge, walk beside a maze of tracks and a tunnel mouth and sneak past the foreman's office. You had to dodge the young cleaners who thought it was funny to tear the pages out of your notebook (as if you had stolen the numbers and the copyright belonged to BR).

You can only appreciate the size and beauty of steam locomotives when you have walked between long, simmering rows of them inside the cinder-strewn semi-darkness of a locomotive shed. That was where the wiliness, the sense of adventure and the courage came in. In the early 1960s, I sneaked around - or was thrown out of - most of the locomotive sheds of the north of England and the Midlands with my friend Adrian and his younger brother Keith, who we always called Our Keith or Our Nipper. At one point, when steam locomotives were beginning to disappear, Adrian started to take collecting numbers literally. He tried to unbolt the front number plate of a vast 12-wheeled freight locomotive in Crewe South shed. The foreman came around the corner. I shouted a warning and we all legged it, leaving the spanner still protruding from the number plate.

That was where the comradeship came in. (But it was, of course, very naughty and I would like to apologise to the ghost of British Railways.)

We pursued all engines, steam and diesel, but we especially pursued the aristocracy among them: the engines with names, wonderful names, absurd names, displayed on great sweeping curves or slabs of brass or steel on their sides.

The Eastern and North Eastern regions, never my favourite, had the silliest names. The old London and North Eastern Railway called its locomotives after racehorses and antelope, which sounds fine until you see a vast, powerful steam locomotive called Pretty Polly or Blink Bonny or Gnu. The Great Western (my favourite) was obsessed with stately homes, and called its engines after castles, halls, manors and granges. The London Midland, my home region, had the widest variety of titles, but was especially taken by royalty and the military.

Trainspotting is usually blamed on a man called Ian Allen, a railwayman who spotted a niche publishing opportunity. He began in the late 1940s to publish a series of small guides, or "ABCs", at half a crown (12.5p) each, listing all the locomotive numbers and names of the six regions of British railways. The Ian Allen Combined Volume, in hard covers at 10s 6d (52.5p), containing all the locomotives in Britain, was the trainspotter's bible.

In truth, trainspotting started long before the Ian Allen ABCs. The Great Western Railway published lists of engine names and numbers from the beginning of the last century. But it was the combination of Ian Allen, the relative affluence of the 1950s, and a willingness (now understandably gone) of parents to allow their children to wander unaccompanied, which produced the Great Age of Trainspotting.

When I was 10 and 11, I travelled, alone or with friends, from a small village in north Staffordshire to spot trains at Crewe, Wolverhampton, Stafford, Shrewsbury, Derby and Doncaster: something that no parent would allow today.

One of these trips stays clearly in my mind. When the train pulled into my village station, Rushton Spencer, the stationmaster, Mr Gibson, asked the driver of the big steam tank-engine if I could ride in the cab. It was only four miles and about 10 minutes to the junction where I had to change into a diesel train. Each second was worth a century.

I was recently given a book on the history of that line, The Churnet Valley Railway by Basil Jeuda. Towards the end of the book, there is a picture of the Rushton stationmaster, Wilf Gibson, shaking hands with the driver of one of the last trains before the line's closure to passengers in November 1960. There, standing in the background, is the 11-year-old, train-mad me.

It has often been pointed out that there are a disproportionate number of railway enthusiasts among the clergy. Trainspotting is obviously close to godliness. It is also - in the honest and accurate reporting of facts, the desperate search for something new - close to journalism. Despite the constant press mockery, there are many ex-trainspotters - closet or otherwise - among my fellow-journalists.

I could name the editor of a leading literary magazine; the deputy editor of an excellent sunday newspaper; a celebrated TV presenter; the diplomatic editor of a well-known daily... I stopped collecting train numbers, in favour of watching football, in my mid-teens, but trainspotting is like malaria. You never quite shake it off. One of my relapses was just before I went to university, and during my first year at Cambridge in 1969-70. I was, for a while, a long-haired, left-wing trainspotter. Another relapse occurred in the mid-1970s when I was a trainee journalist in Bolton, and found a like-minded friend (who is now a BBC producer). I gave up again circa 1974 after I sprained my ankle while running away from the railway police (plain-clothes branch) outside the diesel-locomotive depot at Tinsley, near Sheffield.

When in Britain, I still visit the preserved railway lines and steam centres, trying to brainwash my three children into a love of railways. They are wonderful places but what fun, finally, is a zoo, if you were once a big-game hunter?

In any case, the brainwashing has failed. My son Charles, 13, has turned into an aircraft fan. The other day, I took him to Charles de Gaulle airport, near Paris, to gawp at the planes arriving and departing. They all look the same to me. What on earth do people see in planespotting?