Double-decker bus
The first commercial horse-drawn double-decker omnibuses were introduced in England in 1847 by Adams & Co. of Fairfield, Bow, then improved upon by John Greenwood, who introduced a new double-decker in 1852.
Bus Reshaping Plan
More Swifts went into service in North West London in June 1970, displacing double-deck vehicles. By this time, it was necessary for the LTE to place orders for buses to be delivered in 1972. The Swifts had proved to be little better than the Merlins, and it was decided that all future deliveries were to be double-deck. The first of the DMS double deckers entered service on 2 January 1971, the first of a batch of 1600 delivered throughout 1971 and 1972.