The 63rd International Model Engineer and Modelling Exhibition, which currently deranges the main hall of London's Olympia, is a universe of parallel worlds, each an escape from reality and each governed by people sporting beards and pipes, thick glasses, V-necks, beer guts and terrible shoes.

The only things at Olympia created at 1:1 scale, these people invite you to take part in shunting competitions and war games (choose from a B-17 raid, an assault on Pegasus Bridge or a German paratroop attack on Walmington-on-Sea). They massage Lilliputian machinery with lubricating oil. They offer you tins of paints labelled 'BR Roof Grey' and 'Diesel Yellow'. They try to enmesh you in their world with enamel thinners, angle cutters and automatic wire strippers 'as seen on TV'.

Where else could you find 'Saint David', a 1904 Great Western Railway 4-6-0 - faithful to the original down to the last bolt - within three feet of a Nazi officer feeding a horse of the 'Florian Geyer' SS cavalry regiment in a scene forever 1944? Where else would you see displayed a by-no-means-uninteresting collection of 104 tiny and identical wheelbarrows, each made from a different wood? Unwise, perhaps, to ask why.

But there was nothing to compare with the 30 years of obsessive modelling that has gone into the creation of Howardswood Miniature Cricket Club. This is the creation of the father-and-son team of Peter and Mark Coombs. Peter is a 63-year-old artist (he can whip you up a railway or aircraft scene in just 45 minutes; they can be found at Liberty and the Medici Galleries), who started his Lords-seen-through-the-wrong-end-of-a-telescope while working as a maintenance engineer on Handley-Page Victor bombers in the Fifties.

Mark, 26, is a trained artist who has made his name with the cricketing portraits that feature on collectable 'Design on Sport' cards. Peter and Mark have created a cricket ground down to the very last detail. There are 2,500 spectators to sit on the ground's white plastic seats (John Major included) and all the players (each instantly recognisable) from every current Test team.

The ground features a bar with real drink, lighting, sound effects (applause at the flick of a switch), breezes (courtesy of a small electric fan), the sun (a lamp that moves across the pitch as the one-day Tests - scaled down to one hour, 20 minutes apiece - progress).

'Rain stops play if the phone rings,' says Peter Coombs. Someone suggested that the club would be more realistic with a few clouds. 'Well, I have considered helium-filled white balloons,' says Mr Coombs. Matches are played out in a brick shed at the Coombses' house in St Albans. The ground has expanded so much over the past five years that there is no room for full-scale spectators. 'We did have row A, 1 to 5 for guests,' says Mr Coombs, his flyaway eyebrows taking off, 'but we had to remove it. We needed the space to play and every inch counts.'

The games played at Howardswood are serious stuff. Each takes at least four hours to prepare. Action takes place most weekends or at 8pm on weekdays. Play is interrupted only for tea and telephone. When the crowd has been settled in the stands, the players have arrived by wooden coaches and the sound effects have been turned on (different effects for different Tests), the action starts.

Here comes Botham, bowling in lurid mauve 'pyjamas'. His overarm action is as close to the real thing as the Coombses can make it. Miniature hand-stitched balls are hurled at the batsmen by wire slings (there are hundreds of these) that can mimic in miniature the delivery of every Test bowler (leg spin and googlies included) of recent years.

Batsmen respond in kind, bats propelled by a Coombs digit sheathed inside a finger glove. Balls bounce on a real earth pitch, are whacked for fours and sixes. The crowd cheers.

What does Mrs Coombs make of it all? 'The scoreboard is operated like this,' explains Mr Coombs. Does she think it dominates life in Howard Close? 'We've been awarded a real General Safety Certificate by the Licensing Officer of Hertfordshire County Council,' replies Mr Coombs. 'Do you know that in the 47 Tests we have played to date, 28,136 runs have been scored for a total of 1,076 wickets?' Matches are recorded in tiny scorebooks, kept inside the club.

'We've many more plans for Howardswood,' says Mr Coombs, pointing out a replica of London Transport's Metropolitan Line taking shape under the ground. 'Trains will run every 15 minutes at first during Test matches,' he promises.

Whistles blowing and the smell of hot oil and acrid smoke remind the visitor to Howardswood that other trains are running inside Olympia. One, departing right outside the Coombses' perfect pitch, takes you away through the railway lands of the Chingford and District Model Engineering Club, Napier Power Heritage (a working Deltic diesel no bigger than a Dachshund will haul a half-ton train at 10mph, members claim) and the Nicholas School Live Steam Group.

On the way, travellers must fend off Corporal Jones of Dad's Army fixing his bayonet, racing cars topping a scale 200mph, traction engines huffing and threshing (driven by men smoking), Austrian trams and Hitler's War Machine.

Geraldine Brown of Cannock has won a commendation from exhibition judges for her scenes in the life of 'Bobbie of the 66th'. Apparently, Bobbie was a half-inch-high dog who encouraged 'The last 11 at Maiwand', the small, but perfectly formed Anglo-Indian soldiers under the command of Brigadier General Burrow who were cut down by Ayub Khan's miniature army on 27 July 1880.

Rebuffing the foreign hordes, Bobbie, a precursor of Lassie and Rin Tin Tin, survived to be presented to Queen Victoria at Osborne. His reward? The Afghan War Medal (even though Geraldine Brown has represented Bobbie as a Golden Retriever). Modelling is made of such derring-do and relentless detail.

'What can we do to encourage young aeromodellers?' is the enticing theme of the Aeromodeller Youth Seminar. Grown men race bird-sized aircraft round and round a circuit attached to their champions by pieces of string: as the planes whizz round, the men circle with them until their strings get tangled and they trip over one another.

On the way out to the world of full-sized cars and Kensington traffic, visitors seeking a grip on reality pass perhaps the most significant stand. Here is Christie's, the auction house, with its workshop of 'unique and accurately detailed' aircraft, locomotives and steam lorries.

A 'two-inch scale model of the Hornsby Chain Track Double Crank Compound four-speed, five-shaft tractor originally built for the Arctic Light Coal Co, Alaska, 1910 by R Hornsby & Sons, Grantham' is expected to fetch around pounds15,000. Your preference might be for a one-fifth scale flying model of the Westland Lysander. Whatever, the fervour and microscopic detailing that has gone into the creation of these miniature engineering masterpieces brings its financial as well as it social rewards.

Modelling, the miniature way, keeps hundreds of thousands of mild British eccentrics off the streets and as happy as sandboys, while they invest in the past for the future.

Cue for applause from the Howardswood ground.

The 63rd International Model Engineer and Modelling Exhibition is on until Saturday.

(Photographs omitted)