Mr van de Wetering said the bridge was closed because it was impossible to talk to the man with the noise from traffic and he said the man was easily distracted by pedestrians.
The Fire Service sent members of their crew up the archway and though the man tried to evade them, he was eventually coaxed off the bridge.
The man, of no fixed abode, was arrested for breaching alcohol-related conditions of his bail, and taken into custody.
He would now be assessed by mental health experts.
Mr van de Wetering was not aware of anyone climbing up the archway before, which he said was highly dangerous.
He said people had previously jumped off the bridge into the river and survived but it could be fatal plunge depending on several factors including where they landed and how deep the water was at the time.