TANTALISING reminders of the day nearly 200 years ago that Locomotion No 1 opened the world's first passenger steam railway have been unearthed by roadbuilders.

The original stone sleepers over which the engine ran, on the first day of the Stockton and Darlington Railway, have been found during excavations for the Darlington Eastern Transport Corridor near Lingfield Point.

The railway, which opened on September 27, 1825, used 64,000 of these stone sleepers which were quarried at Brusselton near Shildon. The rails were attached to the sleepers by fixings - called "chairs" - which used two bolts.

However, the sleepers, which weighed about 75lbs each so that one man could lift them, were soon found not to be strong enough and in 1831-32, the whole line was relaid. The new stone sleepers were much bigger and were attached to the rails by four bolts.

Most of the old, unwanted two bolthole stones were rolled to the side and smashed. Some were incorporated into a restraining wall to stop the cutting collapsing onto the track, and it is these stones that have been uncovered.

"We hope we can use them in a display or interpretation on the cycle path," said Councillor Nick Wallis, cabinet member for highways and transport.

More mysteriously, a 100- metre length of parallel lines of sandstone blocks has been also uncovered by diggers. The blocks - each 3ft by 2ft by 1ft - appear to be later than the stone sleepers, but are unmarked by boltholes or cart tracks.

"I wouldn't like to say what they are," said Ben Westwood, of Northern Archaeological Associates, who has been recording them this week. "It's very interesting and any information on what is a nationally important railway would be very welcome."

Most of the blocks and sleepers will be covered by three metres of soil when the road and cyclepath is complete, although their positions will be recorded should future generations wish to investigate further.

* If you have information about what the sandstone lines might have been used for, email chris.lloyd@nne.co.uk or call 01325-505062.