Acoustic monitoring of the Huntingdon rail viaduct has been declared a success by the Highways Agency, delegates to a seminar were told yesterday. The system, known as Soundprint, was developed in Canada and trialled extensively by the Transport Research Laboratory last year. It is designed to pick up the sound of corroded wires in post-tensioning tendons snapping under load and transmit a warning to a remote control centre. (NCE 4 February 1999). Speaking before the seminar, Highways Agency project manager Geoff Chatfield said: 'We are now reasonably confident that the system will pick up any problems with the post-tensioning and expect to install it on another viaduct shortly.'