A new fleet of Docklands Light Railway (DLR) trains have been delayed after encountering “challenges” during testing.
The Transport for London (TfL) commissioner's June report reveals that 30 new DLR trains have been constructed but faced difficulties during the trial phase.
Over the next three years, 54 new trains are set to enter service, with some replacing models that have been in operation since the 1990s.
TfL admitted facing some "complex challenges" but confirmed it remains on schedule to introduce all 54 new DLR trains by 2026.
Arran Rusling, TfL’s head of programme for DLR rolling stock replacement, said: “Our programme of rigorous testing continues of the new DLR fleet to ensure the trains can enter service safely and reliably.
"As part of this we encountered some complex challenges, which means we will introduce the new trains into passenger service later this year."
He added: "We are still on track to introduce all 54 of these new trains in passenger service by 2026, delivering a range of customer benefits including improved reliability and increased capacity across the DLR network.”
It comes after Londoners were invited to have their say on a proposed cross-river extension to the DLR, which could allow up to 30,000 new homes to be built.
A consultation launched in February by TfL asked for feedback on the plan to extend the DLR to Thamesmead - with the potential for further extensions to Belvedere and beyond.
The scheme has been launched to connect Thamesmead with the rest of the city while allowing for a substantial number of new homes to be built.
Thamesmead currently has no Tube, DLR or railway connections to the rest of London, with buses providing the only means of public transport.