THE wrong kind of coal has prevented 170 years of historical hurt being corrected, television viewers will see tonight.

They will also see Sans Pareil eventually get up such a good head of steam that it gives Rocket a real run for a place in the record books.

Tonight's Timewatch programme, on BBC2, is the result of a week's filming on the Llangollen Railway in Wales last autumn.

The TV cameras set out to re-enact the 1829 Rainhill Trials in which the Liverpool and Manchester Railway tried to find the most efficient locomotive of its day.

Stephenson's Rocket won - but was it only because Shildon's Sans Pareil and Sweden's Novelty broke down before they could get going?

Although TV producers are keeping the results secret ahead of tonight's programme, Sans Pareil got off to the worse possible start when it failed to get steam up properly because of the coal.

"The BBC had given us opencast coal from Colombia, and it was very poor quality and wouldn't light," said driver Alan Pearce.

"The Rocket, though, had come down from York with its own coal which had been imported from Poland and which was much better. Eventually they gave us some of that."

But by then the damage had been done, and there was not the time for Sans Pareil's four-man crew - Alan, Malcolm Simpson, Peter Horwood and former Darlington mayor Barrie Lamb - to make crucial adjustments.

The three engines are replicas of the 1829 originals, and Sans Pareil, which was made in 1980 and is more usually seen at the Timothy Hackworth Museum in Shildon, County Durham, is a faithful reproduction.

"The Rocket looks very much like the original from the outside, but on the inside it is nothing like it," said Alan, the curator of Redcar and Cleveland Museum Service. "It was a huge advantage for the Rocket."

However, on the last day of filming, the three engines undertook a speed trial. Although the result is not unveiled until tonight, Sans Pareil, fired by the right kind of coal, exceeded its previous record speed of 26mph.

"We really flogged her," said Alan. "It was a dramatic couple of miles in which we went through 100 gallons of water and one gallon of steam cylinder oil, but we showed that she really was a genuine contender."

* The public are being given a chance to take a closer look at some of the locomotives from the programme.

The National Railway Museum, in York, which supplied the replica Rocket for Timewatch, owns the original Sans Pareil and is also playing host to the Novelty.

On February 1 and 2, members of the trial teams will be giving illustrated tours of the machines for enthusiasts.

Two days of special Rainhill events for schoolchildren are also being planned for February 4 and 5.

* Timewatch: Rocket and Its Rivals is at 9pm tonight on BBC2.

Boiler job not a grate idea

SO DESPERATE were the Sans Pareil crew to put on a good show that former Darlington mayor Barrie Lamb was chosen to crawl inside the engine to find out why it was not steaming properly.

"I was the smallest," said Mr Lamb, who runs a toyshop in Cockerton, "so I had to crawl 3ft inside. Malcolm Simpson had to keep hold of my feet ready to pull me out in case I suffocated.

"Inside was still hot from the night before, and I shouted that my hair was starting to burn, but Malcolm said I'd be all right because there was nothing there to burn."

Although Mr Lamb cleared out a few obstructions, it was not until the coal was changed that Sans Pareil's fortunes changed.