Each of the four coach units carried twenty two high level and twenty four low level seats, a total of 508, with additional tip up seats at the ends of the upper level. This was a total of 1,104 seats on the train, normal trains had 772 seats. Access to the upper deck was via a short stair. Ventilation of the upper deck was by constant running electric fans, as the windows couldn't be opened. The train was higher than other trains so care had to be taken which routes to use it on. The Dartford routes were ideal and no alteration had to be made to the  track and bridges.

The inaugural train ran on 1 November 1949. By 1950 it was decided that no more double deckers would be built. The ventilation of the upper deck was bad, (perhaps that would not be so much of a problem nowadays with no smoking trains) The seats were uncomfortable, and the loading times were slow.

In the end it was decided to extend the trains to ten coaches instead of the eight in use to help relieve overcrowding, these new trains carried 958 passengers seated. This necessitated the extension of platforms of the stations served. In 1953 the platform at Well Hall Station was extended over the road bridge. This was an expensive option, but it had to be done because of the tight curve on the London end of the station.

The double decker train was finally taken out of service on 1 October 1971, after 22 years service and travelling 700,00 miles. Seven of the coaches went to scrap, one of the motor cars was saved for preservation. It is hoped it will be  available for the public to see.