THIS TRAIN with New York-style graffiti made a brief appearance on the Circle Line this week but has now been cleaned up by London Underground, writes Christian Wolmar. Tube managers say that normally such trains are not allowed on the network but they did not want to cancel services during the build up to Christmas: 'We clean it off very quickly because passengers don't like it and find it threatening,' a spokeswoman said. The graffiti was probably painted at sidings during the night. London Underground said that there have been several fatalities among spray-painters who walked alongside live rails to get to the trains. Measures to combat the vandalism, which costs pounds 2m a year to clean, include new infra-red detectors in depots and a 12-strong anti-graffiti squad operated by British Transport Police.