Sir Torquil Norman has designed a flat-pack OX truck for the developing world

He can't remember for sure but Sir Torquil Norman says it's quite likely he came up with his latest invention in the bath, the crucible of many of his best ideas. It was there, while part-submerged, that he decided to buy the Roundhouse, for example. The venue, round the corner from his home in Camden in North London, was shut when Norman bought it on a whim in 1996, rescuing it from likely ruin.

It may also have been in the bath that Norman, who's 80, decided the traditional doll's house would be improved if it were re-imagined as a big, yellow teapot. He called it the Big Yellow Teapot House, and it was a sensation after he launched it with his Bluebird Toys company in 1980.

He was later responsible for the Polly Pocket range of mini-dolls and the plastic lunch box. Norman, who is also an aviator, philanthropist, former Wall Street banker and the father of Jesse, the Conservative MP tipped as a future prime minister, has now directed his brain beyond the playground to the developing world of the future. This week he unveiled a prototype flat-pack truck that, appropriately, looks like a toy. But it has a serious purpose – to provide cheap, reliable transport in the world's remotest places.

The OX would be shipped in pieces, packed six to a standard shipping container (which hold only two standard trucks, Norman says). The vehicle then emerges, Transformer-like, from a box formed by its own trailer area. Assembly is an involved process by Ikea standards but not for a working truck – it takes three handy people 11 hours to build each OX. The vehicle can be adapted to carry people or cargo and supports two tons, more than twice the weight, say, that a standard Land Rover can take. The engine can be used to power a water pump or serve as a generator.

Norman, below, who is 6ft 7in and has the lanky, avuncular charm of a senior Snow brother, has long been dismayed by the car industry's approach to the developing world. "I could never understand how every car that came out seemed to be heavier, more complicated and more expensive than the last. But then you realise the entire industry caters for less than 25 per cent of the world's population, which is insane when you're looking at countries where only a tiny fraction of people have access to vehicles."

The OX's flat-pack advantages include many parts, such as the doors, that can be bolted to either side of the vehicle. Its windscreen is made of three panes, making repairs less costly, and the seats can be pulled out and used as ramps to get heavy cargo in the back or "ladders" to bridge sand that would otherwise give the wheels insufficient grip. The truck, which Norman will sell from his charitable Norman Trust, will cost from £10,000 to £25,000, much less than a shinier model from an established manufacturer.

"A village with an OX would suddenly be independent and could conceivably prevent its young people being forced to move to some terrible slum in a huge city," Norman says. "I think we might just have the tiger by the tail. It seems to me we may be opening a door to making a lot of people's lives better."

Norman is already in talks with several charities that rely on traditional trucks. Riders for Health provides and maintains more than 1,400 vehicles, including motorbikes, for health workers in sub-Saharan Africa.

"There is a real market failure here," says Vinay Nagaraju, who runs operations for the Northampton-based charity. "We still haven't seen big manufacturers, the global players, really look at vehicles specifically designed for regions where there is huge potential to drive the economy forward."

Riders for Health typically sources vehicles from the big makers, shipping them at great expense for use in projects such as community immunisation programmes in remote villages. Further funds are required to adapt vehicles that are inevitably designed with less-than-hostile environments in mind. Their typical useful working life in the field is as little as five years. Norman believes the OX could keep rolling for 20 years or more.

"It's a very promising vehicle because it is also durable and versatile," Nagaraju adds.

Norman has competition. Joel Jackson is a young social entrepreneur from Sheffield who was advising a forestry enterprise in rural Kenya in 2010 when he, too, observed the lack of good, rural transport. Mobius, the 28-year-old's new Mombasa-based company, has already built a second prototype car that swaps frills for practicality, offering a rugged all-terrain vehicle that will cost just £4,500.

"I thought it could be game-changing if we could provide a platform for mobility that would bring out latent entrepreneurialism across Africa," he told Wired magazine. Mobius will also offer business advice to customers and even help them find financing, but also plans to be a profit-making enterprise.

Others have failed where Norman and Jackson hope to succeed. Back in the Live Aid era of the 1980s, Sir Torquil was originally inspired by a book called Africar. It accompanied a Channel 4 series of the same name that charted the efforts of a man called Tony Howarth to build a cheap vehicle for the continent. But his plywood invention got seriously stuck in the mud when he was found to have been less than honest in dealing with the project's backers. In 1994 he was imprisoned for fraud.

A seed had been sewn and Norman has finally found the time in his later years to do the job properly. But, at 80, should he not be slowing down a bit? He laughs. "I only stopped flying a fortnight ago," he says. "My partner and I took my old Dragon Fly up for a run. I'd just fitted new cylinder heads and it was smooth as silk."

Norman is fanatical about planes and has amassed a vast collection of classic flying machines. In 2007 he stepped down as chairman of the Roundhouse Trust and later wrote a book, Kick The Tyres, Light The Fires: One Man's Vision For Britain's Future And How We Can Make It Work. His personal visions may now be firmly at ground level, but there's no holding him back. "I think if I started taking it easy I'd be dead," he says, still laughing.