Isambard Kingdom Brunel’s suspension bridge straddling the Avon gorge is a keystone of Bristol’s urban landscape. But imagine if it did not exist and the gorge had still to be crossed. What then?

Pupils of all ages, as well as practising engineers, are being challenged to conjure up new ideas in the Clifton Crossing Competition 2006 to mark the 200th anniversary of Brunel’s birth. It sounds simple: given a picture and cross-section of the gorge, along with the original brief, work out how to get a standard-size lorry from one side to the other. Brunel’s wrought-iron link design, slung 214 metres between two sandstone towers hewn into the rock walls, prompted much contemporary debate: would it work; was it affordable?

The great engineer was just 24 when he won the competition in 1831, but the bridge did not open until 1864, five years after he died. Under 21st-century rules, the solution need not be a bridge - it could be whatever springs to mind. It should, however, “complement the aesthetics of the gorge”.

The contest is being run by the University of Bristol and New Civil Engineer magazine. Responses from schools and individuals are flowing in - around 300 to date. The deadline is April 9, Brunel’s birthday.

If the university can obtain funding from the Research Council, it intends to work closely with At-Bristol (a harbourside venue which houses science, nature and art attractions) to develop a package of materials. There are also plans to exhibit the winning entries there, before taking them on tour.

Only conceptual designs are sought, in the form of an illustrated poster.

However, professionals taking part have an incentive beyond kudos and a chance of winning pound;5,000. “We want them to put forward design concepts that can be used to develop educational activities,” says one of the principal organisers, professor Colin Taylor, of Bristol’s department of civil engineering.

“At primary level we would like to achieve an understanding of what a civil engineer does - at nursery and early primary it will be really about just drawing a picture. We want to show engineering is fun,” says Colin. “At secondary level we’ll be looking more for form, aesthetics, practicalities - also initiative and vision. We hope the long-term impact will be to get more people studying maths and sciences.”

He explains that the competition also gives young professional engineers an opportunity to engage with schools.

Paul Anderson, head of technology at Birkdale High School, Dewsbury, has involved several year groups. “There’s a Year 7 project on bridges and structures, based on the national curriculum. We thought it would give a nice focus - the Clifton bridge is a real example.

“We’re also using it to develop creativity for Year 8s. We’ve been stunned by the variety of ideas - one was for a magnetic roller-coaster system. For Year 10s you can take in more detail, such as working out the strength needed to convey vehicles. Someone came up with an enclosed tunnel to stop cars falling off - or people jumping off.

“One of our challenges is to get more pupils engaged in engineering and the competition has been a good handle for that. I don’t think any of them have been to Bristol and they knew little about Brunel beforehand.

“What helps is the material: one picture of the bridge; then another with it edited out. It means they start with a clean slate. The competitive element has helped hugely. We have a lot of low-achieving boys in Year 7 who have produced work of a calibre you wouldn’t have expected. A surprise to us was that pupils decided to form groups - one of the skills we try to teach is the value of teamwork. It means we can take a hands-off approach.”

At Wyvern Community School in Weston-Super-Mare, Years 7 and 8 have been involved. “We ran it as a lesson - we had a week-long design project. Almost everyone here has seen Brunel’s bridge,” says Mike Jay, head of DT.

Studying the 1831 brief in all its glory is an exercise in comprehension as well as science and design. “Pupils had to write their own specification from that original,” says Mike.

There were no roller-coaster ideas here: all the pupils came up with a bridge. “We gave them a lot of support material, with pictures of modern bridges, and through this they developed striking designs. We projected the image without the bridge on to a whiteboard for pupils to put on their own design with a marker pen. It was a very immediate way of getting peer review.”

Mike Jay is planning to submit two dozen entries. “It’s been valuable in exercising pupils’ imagination and showing how important design engineers are in the environment around them,” he says.

* Entry details are at research.cen.bris.ac.ukcc06

The individual winner and winning school will each receive pound;1,000 and a plaque. Judges include television presenter and Brunel expert Adam Hart-Davis, and Michel Virlogeux, designer of the Millau viaduct in France.

Winners will be announced at a dinner on July 6