 Trailer cars were modified with new control cables compatible with the new motor cars and heaters, as the line to Ealing was not in tunnel, and two groups of stock formed, known as Tunnel (or Local) Stock and Ealing Stock.As traffic to Ealing increased, in 1925/26 eight of the original motor cars were modified to augment the Ealing Stock.Services were mainly provided by 6-car trains, although off-peak 3-cars were provided west of Wood Lane.