A large majority of the RT family were supplied by AEC.  However, as part of its requirement to use more than one supplier, London Transport also purchased over 2,100 Leyland Titans.  The RTL class were designed to carry bodies identical to the RT, whilst the 500 members of the RTW class were London's first eight-feet wide double-deckers. 

 

The prototype RTL, RTL501, appeared in 1948 and was the only RTL to carry a roof-box body when new.  It was numbered 501 as it was originally intended that the RTWs would be numbered in the same sequence. 

 

For engineering reasons, garages were grouped as AEC and Leyland sheds, although some garages changed allegiance from time to time.   Edgware had some RTLs alongside its RTWs in the early days, but after 1952, the RTLs seen in the area came from long-time Leyland garages like Willesden and Cricklewood.

 

The Leylands were not as long-lived as the RTs, being less popular with drivers, as they were considered to be noisier and have heavier steering than the RT.  The last RTL in service was RTL543 on the 176 from Willesden in November 1968.