The villain leaves that stop trains

It's that time of year again, the season of mellow autumn tints - and those leaves on the line which will soon bring chaos to rail commuters. Only this year, we are promised, it will all be much, much worse. The wet, warm summer has, says Railtrack, made this year's crop of autumn leaves "bigger and juicier" than usual.

To combat them the company is about to mount most expensive campaign ever embarked upon, using 1,000 workers on call from 3am, and new hi-tech equipment.

There will be multi-purpose vehicles on patrol, equipped with high pressure water cannons and powerful sanding devices. A fleet of "sandite" trains are standing by to apply hundreds of tons of sand-glue gel designed to stop the train wheels from slipping. A new citrus-based juice mixture, nicknamed Agent Orange, has been devised to soften the Teflon-hard coating caused by squashed leaves. There are automatic sandite applicators positioned at key skid spots and hand-held sandite guns issued by the hundred to track staff.

There are track scrubbers, sandsticks and "hotspot" teams. Leaf-fall control centres have been set up, a satellite-based "Low Adhesion Warning System" will be in operation to flash intelligence of skidding trains from on-board sensors, there are miniature trackside weather stations to help predict the quantity of leaf fall, there are leaf guards and leaf fences.

The whole operation will cost tens of millions of pounds. And those of us who rely on the train will still end up frustrated and, above all, very late. So which are nature's arborial rogues responsible for creating such chaos?

Martin Buckland, of the environmental consultancy ADAS, who is vegetation adviser to Railtrack, is in no doubt: "There are six species of trees which cause most trouble and they are the ones we are targeting." Together or individually, says Mr Buckland, the Sinister Six produce the seemingly impermeable track coating which scientific analysis has identified as "insoluble, lignified cellulostic material containing glue-like proteins and other protoplastic compounds."

"Between mid-October and mid-November it's these trees that will make life difficult." Mr Buckland profiles the culprits and gives his own "squidge rating".