A protest by a man dressed as Spiderman has closed Tower Bridge and caused traffic jams around the London landmark.
Mr Chick overcame his fear of heights to climb the crane
David Chick put aside his fear of heights to scale the 100ft crane at dawn on Friday, to protest about fathers' rights.
Mr Chick says he has been denied access to his three-year-old daughter despite the courts allowing him to see her.
He chose Spiderman because he is his daughter's favourite comic book hero.
Police closed Tower Bridge in both directions at 0630 BST, causing traffic delays.
A trained negotiator is trying to coax down Mr Chick, who has unfurled a banner reading 'In the name of the father'.
It is the latest in a series of protests by the campaign group Fathers 4 Justice.
These have included storming Court One at the Family Division of the High Court in June and a rally in central London on 22 October.
Edward Gorecki, who dressed as Batman in a recent protest on the roof of the Royal Courts of Justice, is one of Mr Chick's fellow campaigners.
He said: "He's a tough old boy. He doesn't really like heights but he is a desperate man.
"It was freezing cold last night and teeming down with rain - very slippy up there and very dangerous. But like any man he will do anything to see his children."
After the Batman and Robin protest, government minister Lord Filkin, who has responsibility for the family law system, agreed to meet Fathers 4 Justice members at a future date.