A device manufactured in East Lancashire could make safety checks on railway lines such as those involved in the Cumbria rail crash easier.

The bright yellow invention, named Checksafe, responds to movements in the nut or bolt it is placed through, indicating whether they need tightening.

Checksafes have been approved by Network Rail and can be placed at all points on the railway network and a quick look is needed to check whether its triangular pointers have moved out of line.

But it has not yet introduced the system.

The safety indicator is part of a range invented and developed by Business Lines Ltd in Kirkby Lonsdale, Cumbria and is manufactured by a Blackburn based plastic moulding company, Verifyne Plastic products Limited, in Slater Street.

The Checksafe was developed five years ago and the London Underground tube network has them in use.

But Network Rail does not use Checksafe, although trained maintenance workers manually check the track using a specialist spanner.

Following the crash near Kendal which claimed the life of a Glaswegian woman, Margaret Masson, 84, Network Rail has completed 700 additional precautionary visual inspections of points.

And it is believed that part of a set of points to the south of the crash was missing.

Alan Holderness, managing director of Verifyne Plastic products Limited, said: "We have been producing the product for Business Lines.

"The Checksafe is produced specifically for the railways because we mould the plastic for a square nut rather than the hexagonal nut used on vehicles".

Mike Marczynski, managing director of Business Lines Ltd in Kirkby Lonsdale, Cumbria, said: "The idea for the Checksafe was developed from an invention to check whether nuts or bolts had moved from wheels on vehicles when I ran my waste company."

A Network Rail spokeswoman said: "Network Rail takes safety very seriously and we have a thorough maintenance regime.

"Our maintenance regime includes a thorough inspection regime for points on the network."