Nineteen people were being rescued from a fairground ride which became stuck 20 metres above ground.
Firefighters had spent more than three hours retrieving adults and children from the ride on the Southbank in central London and were expected to work late into Sunday evening rescuing those still stuck.
The ride, with hanging capsules that swing around a central pillar, is a popular attraction on the Southbank.
London Fire Brigade (LFB) were using two aerial platforms to bring people down and have so far rescued people from five out of the 10 stuck capsules.
Crews were also working with an onsite engineer to manually release the ride's friction brake so that it could be turned around and aligned with the aerial ladder.
LFB station manager Clive Robinson said people on board were waiting patiently to be rescued.
"It's slow work as we need to access each cage on the ride individually and ensure they are secure before we move them from the ride onto our platform and bring them back down to the ground.
"There are no injuries and everyone is patiently waiting for us to get around to them."