Sir - In ’Maglev all the rage again’ (RG 8.01 p504), you described Shanghai’s Transrapid as ’the world’s first commercial maglev project’. Surely, this depends on how you define commercial.

The maglev peoplemover at Birmingham Airport was ordered 20 years ago, inaugurated in 1984, and is now being converted to cable operation. In common with other airport peoplemovers running on rubber tyres it was free at the point of use, but it was supplied as a commercial venture. That it turned out not to be ’commercial’ in the long term is another matter.

Birmingham had a simple reaction plate. A 30 km long stator winding seems a perverse alternative to roller bearings and wheels to support and guide rail vehicles. I trust provision has been made for Shanghai to revert to common-sense mechanical engineering in 20 years’ time.

Roger Ford

Welwyn Garden City, Great Britain

Tram-trains too

Sir - Your article ’SNCF pioneers the tram-train concept’ (RG 7.01 p467) ignores the fact that in the USA the New York, New Haven & Hartford Railroad operated trams on over 160 km of steam trackage between 1895 and 1925. Some of the cars were owned by the railroad, while others were local city trams.

J W Swanberg

Connecticut, USA