One more train impostor, and I'll come off the rails

I have a friend called John who lives in the same valley as me, and is a steam nut, so every now and again he rings me up to tell me that there will be a steam special coming through tomorrow, and even the name of the engine pulling it.

And I sigh, and say to myself: "Honestly, what's the point of planning your day around a chance to see a steam train for two minutes?"

And then I plan my day to make sure I go out and look at it. Just to please John, of course.

Last week, for instance, he rang me on Wednesday and said: "John Potter steam-train forecasting service here. Flying Scotsman coming through tomorrow. Leaves Bath at 12.47pm, so gets to us about 12 minutes later. Worth seeing the Flying Scotsman in the flesh, I should think, especially as it's just been refitted."

I should think so, too. In fact, I had seen it in the metallic flesh once before. In the 1980s I presented a series of half hour programmes for BBC 2 called Steam Days, and we were allowed to film on board the Flying Scotsman one day when it had just come out of refitting somewhere near Carnforth and was doing a test run on, I think, the Settle-Carlisle line. We had done most of the filming, and most of the testing, for the day, but the hundreds of gricers on board wanted to stop at one station to let the engine to have a run past, so that they could stand on the platform and film it or snap it at speed, then get back in their coaches again.

The train crew off-loaded us all at the station.

They went back down the line.

They got a head of steam up and came roaring back again, smoking and hooting.

Suddenly there was a bang and a flash of metal from the wheels. A bright object flew off. The train slowed to a halt. They discovered that some coupling or other had broken, and the engine was now down to one cylinder less than before. There was great chagrin among the crowd, mingled with pride that they had actually been there to see this amazing accident, and we all got on the train and limped slowly back to base, which took hours.

And the train didn't half sound funny. The sound, instead of the regular four beats in the bar, was three beats and a gurgle or three beats and a click, or three beats and something - anyway, it was a sound you wouldn't want to hear an engine make. And while the film crew was packing its gear away, a punter came past our compartment and said to the BBC sound man: "Hey, have you recorded this?"

"Recorded what?"

"The sound of the Flying Scotsman on three cylinders."

"No."

"But you've got to!"

"Why?"

"Because it's a unique sound! If you don't record it, it may never be heard again! It's a unique record. You've got to!"

The sound man looked at his carefully packed gear, and looked at the pleading expression on the man's face. He considered the matter carefully.

"Piss off," he said.

Yes, I'm afraid there will always be a gulf between the anorak and the professional. But there was enough of the anorak in me to go to the best possible vantage point on Thursday, in the field beyond Freshford Station, where the line sweeps round in front of you, and to wait for the Flying Scotsman to come. When steam trains come through the valley, they usually hoot like mad and announce their coming. (Steam engines are the drama queens of the train world - all puffing and attention-grabbing and showing off their big wheels and couplings like legs in black net stockings.) When finally this one came, it slid almost silently out of the trees - and I immediately saw why.

It was a set of Pullman coaches all right, but it wasn't the Flying Scotsman at their head at all. It wasn't even a steam engine. It was a big sleek diesel called Prince Henry, which however efficient and grandiose, was not what I was waiting for. The Flying Scotsman had clearly broken down again. In the theatre they would have said, "Due to indisposition, the part of the Flying Scotsman at today's matinee will be played by Prince Henry."

I don't care. That's twice in 20 years it's let me down.

One more chance, and that's it.