A electronic device which could help prevent rail disasters and which is one-third the size of a matchbox was being unveiled today.

The tiny gadget fits on the wheel axles of trains and can detect abnormal stresses on them which may be caused by problems on the track.

A powerful microprocessor then uses satellite technology packed into the system to pinpoint exactly where the problem is along the railway line.

It can then relay a rapid warning to train operators via a mobile phone signal.

Tests on the Microlog, produced at Newcastle University, are due to start shortly on the GNER East Coast mainline.

It was being unveiled at the university's new Stephenson centre, less than a mile from the factory where Robert Stephenson built his engine The Rocket in the nineteenth century.

Science and innovation minister Lord Sainsbury was viewing Microlog at the official opening of the centre today.

It was to be on display alongside a small replica of The Rocket to demonstrate how far railway technology has developed in 200 years. The highly-advanced miniature data logger weighs less than ten grammes and boasts a four megabyte memory.

It works by being installed on the train's wheel axles, which bend and twist under stress as the train runs along the lines at high speeds.

It can detect any abnormal stresses which could be caused by problems on the track - for example, buckling due to excessive heat.

Results are sent to a computer miles away which uses a highly-sophisticated software package to analyse the data and alert rail bosses to urgent problems.

The device could also lead to a better understand of wheel-rail interaction and improve axle design.

Microlog is the product of years of development by scientists with Newcastle University's Design Unit.

They have exploited highly advanced technology to create the miniature device and some components are so small they are hardly visible to the human eye.

Lead researcher Dr Jarek Rosinski, who developed Microlog with his 18-year-old son, Martin, said: ''Although data loggers have been used for more than two decades, they have always been relatively big and their use has therefore been limited.

''Microlog is unique because of its miniature size, which allows us greater flexibility and means we can to fit it to smaller components such as train axles. The computer software which accompanies it is also extremely sophisticated.

''We have been working over several years to perfect the design and we are confident it has huge potential in a variety of applications, rail safety being just one of them.''