LBHF admit that "many of the components of the bridge have already theoretically exceeded their fatigue life".July 2023

In a response to an HBSOS FOI, LBHF confirmed that many of the components of the bridge have already theoretically exceeded their fatigue life. This surely throws into doubt how long it is possible for the bridge to operate as a pedestrian and cycle bridge until it needs to be fixed, closed to pedestrians and cyclists, (as in 2020 for nearly a year...!). If it can't be fixed, it would have to be dismantled...

26th July 2023

Dear [HBSOS]

Thank you for your email to Cllr Cowan of 23rd June 2023 which I am answering on his

behalf. I have chosen to respond outside of the formal FOI process request which

enables us to give you more information than you would receive otherwise. I hope you

find that helpful.

Your Request and Our Response:

Q1. In March there were meetings with Foster/Cowi as a prelude to planning

applications. Application 2023/00778/LBCHF for inspection pits was due for

decision over a month ago. Please confirm when that work is expected to be

completed, what impact that work will have on the proposed deck reopening

(Autumn 2023?), and if the Council intends to complete that work prior to filing

applications for Foster/Cowi.

The planning application has been submitted and is in the process of being validated

by the planning authorities. It is not connected with the deck being opened. That

decision will be taken by the CCSO, once stabilisation is complete, provided they deem

it is safe to do so.

Q2: Please confirm (a) the maximum weight vehicles your experts expect the

bridge to be able to carry following stabilisation works, (b) the expected

longevity of the existing deck at that weight, and (c) if it is expected that Tucan

4.1T Dial a ride buses, Police cars, and Ambulances (4.25-5T) will be able to use

the bridge?After the stabilisation works are completed this summer, the

structural integrity of the bridge remains sub-standard.

It is important to recognise that many of the components of the bridge have already

theoretically exceeded their fatigue life. Based on the Engineering Fatigue Performance

report, it is envisaged that following stabilisation there will need to be further restrictions

imposed including a vehicular weight restriction of 1.5 tonnes in each direction at any

one time. This obviously precludes the vehicles you mention along with other options

eg: Possible’s e-pods concept. We are however looking at options for e-mobility

transport within the weight restrictions. The Continued Case for Safe Operation

(CCSO) will remain until the bridge strengthening and restoration works are

undertaken. The CCSO will continue to assess the bridge and determine what use is

permitted.

Q3: The pedestals are now stronger than before when the weight limit was 7.5T

(and 14T buses used the bridge). If the answer to 2(c) is no, what additional work

would be required to allow such vehicles, how long that would take and how

much would that cost please?

The strengthening and restoration works are extensive. The difference in works

between the bridge being strengthened and restored for pedestrians and cyclists only

versus the bridge being strengthened and restored for traffic and buses is minimal. The

estimated restoration and strengthening costs to keep the bridge open to pedestrians,

cyclists and river traffic (without the need for ongoing maintenance, monitoring and

CCSO approval) is around £210M, very similar to the £220m estimated costs to reopen

the bridge to traffic and buses and the vehicles you reference. The majority of the costs

relate to restoration works and strengthening works to support the dead weight of the

bridge (80% of the design load).

Q4: What is the current expected cost of a standard repair with a pedestrian

bridge to the Riverside slipway and is that now cheaper than Foster/Cowi? We

understand 75% of the estimated £20m pedestrian bridge cost was for piers and

abutments. Is this correct and what more viable alternatives are there?

The DfT Taskforce agreed that the bridge should be strengthened and restored so that

it can be reopened to traffic and buses. The bridge is currently open to pedestrians

and, apart from a few brief planned closures, is expected to remain so. Therefore, we

do see any need for an alternative pedestrian bridge and do not hold an updated cost

estimate for this proposal.

Q5: The council's recent estimate of £230m is for DBFM with a toll. How much

would (a) Foster/Cowi and (b)a 'standard repair plus pedestrian bridge' cost as a

DB project. How much would LBHF be prepared to contribute without imposing a

toll, provided that Central Government/TfL were to prepared to offer a

significantly greater percentage of the total cost?

The pros and cons of the various procurement options were assessed in the Cabinet

report of October 2022. The Cabinet agreed that the DBFM option is the best way

forward taking into account our overall objectives. With regard to your question about

contribution, we have made it repeatedly clear that the H&F contribution can only be

met through a toll or road user charge and furthermore a toll or RUCS is also required

to guarantee the ongoing and necessary maintenance of the bridge. H&F is already

looking at sunk costs in excess of £20m since the bridge closure.

Finally can I say we share very much your desire to see the Business Case Approved

by the Department for Transport and for confirmation of the funding mechanism for the

full restoration and strengthening.