Twelve 'hush' buses for London Transport
Page 25
If you've noticed an error in this article please click here to report it so we can fix it.
• London Transport is about to become the world's largest operators of quiet buses. Later this year — at a date still to be specified — it is to take delivery of no less than 12 quietened versions of existing single-deck buses.
Six of these will be Metro-Scanias similar to that exclusively tested by CM last year. In our noise tests, carried out to British Standard conditions (accelerating from 31 mph), the Metro-Scania obtained an exterior noise level of 76 dBA. The same figure is said to have been achieved in similar tests by a new version of the Leyland National, six of which will also enter service with LT.
This National, like the Scania, is quietened by encapsulating the engine. The extra panels are said to be easily removable for maintenance. A forced cold air cooling system is provided, air being drawn from an upward facing duct and across the engine by a fan. Additionally the Leyland 510 engine used has altered torque and power curves which give reduced noise and fuel consumption without loss of performance. A fluid drive to the engine fan also helps to cut down noise.
Interior noise level is a claimed maximum of 76.5dBA. This is achieved by redesigned floor trim and insulation. The figures quoted, though similar to those claimed for the Scania, are nevertheless substantially worse than those which were said to be achieved by the first quietened National (CM, December 15). However, the version now being produced for LT is very much a production vehicle, writes Martin Hayes, and further developments along the lines of the DAB-developed bus shown at Workington can be expected later.
British Leyland was this week reluctant to quote a price for the quiet package, but Mr Ron Ellis, managing director of BLMC's truck and bus division, told me last year that the cost should be about £500-£600.
The quiet Scanias and Nationals are on show at today's "moving people in cities" conference at the Transport and Road Research Laboratory (a full report of whch will appear in next week's CM).
As exclusively reported in CM, LT's 12 quiet buses will initially spend 12 months in service on route S2 (Clapton-Bromley). The route is currently operated by 12 MBS single-deckers.