However, TfL chiefs insist the new trains will begin entering service “as quickly as possible” and that all 54 new trains will be running by summer next year.
Those trains remain in the CAF factory, where they were built, after signalling difficulties and the collapse of a TfL contractor behind a depot required to store the trains in London.
A TfL spokesperson said: “We're introducing 54 new trains to replace the 33 oldest trains in our fleet, some of which are more than 30 years old.
The delay was also caused by difficulties integrating the braking system on the driverless trains with the track signalling system — while enabling the existing DLR trains to keep running.
“The new trains will help us to improve the frequency and reliability of services and support population and employment growth across the network, particularly in parts of the Royal Docks and the Isle of Dogs where the DLR is the main transport option.
