That’s according to the engineers advising bridge owners Hammersmith & Fulham Council.
The 134-year-old Grade II listed bridge was urgently closed last August on public safety grounds.
The Council commissioned a temperature control system at an annual cost of £420,000 to offset temperature extremes on its chain supports.
A 259-page report by bridge engineers Mott McDonald has now revealed that the temperature control system has been a success.
But the safety board says the bridge cannot be reopened until the system has shown to be effective over a full range of temperatures.
The council welcomes the news but says further stabilisation work is needed in order to get it open for cyclists and pedestrians again.