El Tren Fantasma, Radio 4, Saturday<br/>The Ghost Trains of Old England, Radio 4, Wednesday

Trains make really good television. But until last week I hadn't realised what really good radio they make as well.

It took an expert to convey the audio joy of rail travel – a sound expert, not a train expert. Chris Watson is a sound recordist, and there's as much of an art to that job as there is to being a top photographer. Watson is a man who knows where to put his microphone, and one of his assignments, in 1998, was recording the sound for an episode in the Great Railway Journeys TV series.

The job took him to Mexico, and the now defunct coast-to-coast train service from Los Mochis to Veracruz. I don't know why it took 12 years for Watson, or whoever, to realise that his old tapes constituted a treasure trove of atmospheric sounds, but I guess when you go off to make a TV programme you're probably not thinking that there might be a radio programme in it is as well.

So, what we had was a documentary – El Tren Fantasma (The Ghost Train) – in which Watson packaged up the month that he spent riding the train, using his original recordings, adding his own narration, throwing in some interviews, and creating something magical.

One night Watson and his mic were allowed into the goods yard in Chihuahua as steam trains were being shunted to and fro. The orchestral hiss and clang of these "great beasts", as Watson called them, was the most thrilling noise to come out of my radio all week.

Back in the UK, The Ghost Trains of Old England was equally memorable, a wonderfully bonkers half-hour in which Ian Marchant highlighted the absurdity of officialdom, and the joy of train travel, by seeking out the services we're not supposed to know about – the ones the rail companies do not want to run but can't shut down for legal reasons.

Marchant delighted in riding the once-a-week service from Stockport to Stalybridge, on which he gently broke the news to one of the eight other passengers that there was no return train. "Oh crikey," came the reply. You had to hear it to realise how funny this moment was, in a programme that was about so much more than its surface topic. After the contortions Marchant went through in trying to buy a ticket from Newhaven Marine, you'd believe Kafka had been an Englishman.

Finally, a memo to Mark Radcliffe of Radcliffe and Maconie (Radio 2). Mark, you're a broadcaster of genius but those mentions of a certain daily newspaper are getting a bit much. Isn't the BBC supposed to be being careful about this sort of thing?