The Council continues to press with TfL the concerns of borough residents and businesses to get the Hammersmith Flyover reopened as soon as possible.
Cllr Nick Botterill, Deputy Leader of Hammersmith and Fulham Council reports:
The assessment work has taken place inside the box sections so this is why no apparent work is visible. I am due to go inside the box sections myself on Tuesday to look at the situation and see the strain gauges going in.
In the medium term TfL is confident that a full remedial solution (involving creation of new tension steels) can be put in place before the Olympics and will give the flyover an extended life of around 10+ years. The work to do this will be undertaken as much as possible overnight.
The head of Transport for London, Peter Hendy, has sent Nick the following email:
Good to speak to you just now.
Here is a hopefully concise position statement on the Flyover you can use and pass on to your colleagues as well.
The Flyover was built in the early 1960s. It is a unique design, with the pieces between the piers at right angles to the carriageway and suspended by internal cables, and as originally constructed, a thin deck with internal heating designed to avoid salting in winter. This latter feature, however, never worked. When TfL inherited it, in 2000, it has never been waterproofed properly but had in fact been salted each winter with resultant penetration of salt water into the structure and the
steel cables holding the sections up.
We did waterproof it some years ago, but much damage had already been done. For the past couple of years we have been monitoring the condition of the structure and until very recently had thought we needed to take action on a 5/8 year horizon. The inspections last week, however,
revealed that at least between one pair of piers an advanced deterioration of cables to such an extent that if replicated in all the cables in that pair of piers, immediate action needed to be taken. Hence we closed the road, and took advice from the world expert in pre-stressed concrete box girder bridges, who confirmed we were right to remove the weight of traffic.
Since then we have (a) erected some propping from below in a couple of the worst affected places; (b) put in a 24/7 invasive examination and inspection programme of all the structure and particularly the cables (virtually all this work is inside the structure rather than on top of it); (c) had people working 24/7 doing the structural calculations as results come in to assess the state of the structure so we can see what we can do with it in the short term, and what remediation is best in the medium to long term; and (d) had a third 24/7 workstream of people designing the long term solution.
We will not be able to open next week, as whilst the inspections will be concluded, the structural calculations will not be, and we also need to put strain gauges on the structure and also check the completed workings with our expert. We are however hopeful of some return to traffic by the beginning of the week after, as the processes above conclude, but will only be certain what we can do next week.
We are also very confident of a design solution which will replace the strength of the rusted cables and give another 10/15 years life, and of a return to normal operation before the Olympics.
There is no question either of demolition nor of traffic never returning to the structure; we know that there is a long term solution. If more cables were not to work, we could prop it all, but that would be complex, costly, unsightly and difficult in places.
We have put in traffic management measures to allow the best throughput possible whilst allowing normal cross traffic, and put out a lot of information in real time and in the media. Another release is imminent. Leon Daniels will come over to brief you on Tuesday afternoon and will fix for you afterwards to go inside the structure to see the works.
Regards; any more questions, please ask!