Why European railways go faster round the bend

Tilting trains were the great flop of the Eighties in Britain, but they are becoming commonplace in most of Europe. It was Britain that developed the idea of installing a tilting mechanism to allow trains to go faster round bends. The limit to speed is not the angle of the tilt but the comfort of passengers. The tilt mechanism ensures carriages "ride" smoothly with bends.

Or so the theory went. But BR's version, the Advanced Passenger Train, was ridiculed because the tilt mechanism kept breaking down. Brian Mellitt, Railtrack's engineering director, who was involved in the APT's development , said the cause of the problem was that the train did tilt too much.

The APT was scrapped although many engineers who worked on it said errors on the prototype could have been ironed out, with the train in full service by the mid-Eighties.

Tilting trains are all the rage in Europe as they allow faster line speeds without big infrastructure renovation. Marzio Broda, of Fiat Ferroviaria, the most successful of the two companies now producing tilting trains, said that the key change was to install a gyroscope to indicate when the tilt mechanism should come into play. "Previously, there was only an acceleramotor [a mechanism using springs] to detect the bends ... but this also detected bumps on the line, causing too many tilts." Fiat's trains have now been sold to Finland, Germany, Switzerland, Spain, the Czech Republic and Portugal - and 25 trains of 46 ordered are currently operating in Italy.

The other firm, Adtranz, has trains in Sweden and Norway, but these are hauled by non-tilting locomotives. Recently James Sherwood, president of the UK firm, Sea Containers, said he hoped to order two tilting trains for the East Coast Main Line.