4-tracking through to Wantage road will involve demolition of several houses through Steventon and closure, bridging or upgrade of 2 level crossings. Building a new bridge twice as wide as the old one means the road must be upgraded to current standards of width, gradient and sightlines. If you replace the bridge like-for-like you can leave the road substandard. The cost difference between these 2 options is vast. Therefore, as a public body, OCC will want to avoid unnecessary costs.
I'm fairly sure that if the bridge authority requires access to the railway to carry out work it will be liable for all of NR's additional costs, which include compensation to operators for closing the line. Funadmentally, NR didn't intend to close the line and will be financially worse off for having done so. Why should it pay for OCC's failure? Happy to be corrected on that though.
What do you mean by 'Oxfordshire County Council's failure'? How exactly has the council failed?
The decision to refuse listed building consent for demolition of the bridge was made by members of Vale of White Horse District Council, as it is the local planning authority, not the county council. It was a democratic process, whether or not people like the decision.
I expect that if it comes to it, Network Rail will be asked by the county council to engage specialist contractors to carry out the demolition and replacement of the bridge using the plans that were prepared some years back, and that it will be possible to achieve most of this in weekend possessions. As it happens, this month would have been a good one, as the line is closed between Didcot and Swindon for the next four weekends for track renewals in the Swindon area.
An old Brunel-designed twin-track overbridge across the fields from my home was knocked down in the early hours on a Saturday, with the rubble cleared, the existing abutments reconstructed and new pre-cast concrete deck and parapet sections lifted and fixed in place by Sunday evening, with the trains running again first thing on the Monday morning and the finishing touches then made to the bridge with no further impact on train services
Stevenson would likely be more complicated, given the gap to be bridged and the awkward location, with buildings close by, but if a single span is used, work on adapting or replacing the abutments would be taking place well back from the running lines, so should probably be able to proceed with trains still running.
But until the NR and county council engineers can take a close look at the whole structure - presumably during this month's possessions - and decide the best course of action, we will just have to wait and see.
Anyone interested in the historic structures along the GWML - and the route's overall design and development under Brunel and subsequently - may find this report commissioned by Network Rail in 2012 interesting. Off the back of it, English Heritage, now Historic England, listed many more structures.
English Heritage lists or upgrades status of dozens of bridges, tunnels and other structures along 'God's wonderful railway'
www.theguardian.com