Bridges 2024, Coventry, 13 March
Reveal 4D
The website for Reveal 4D is https://reveal4d.com/ . Reveal 4D has been in development for some years, and in use internally by BHA Ltd and by clients of our photogrammetric survey work.
Bridge of the Month
The Briidge of the Month newsletter was started by Bill Harvey, who wrote an article every month for nearly 12 years, the last just a couple of weeks before he died. I have taken it up since, as a vehicle for learning and teaching. Sign up for notifications by email (pop-up form bottom right) or connect or follow me on LinkedIn. The back catalogue is available.
Collaborative Reporting for Safer Structures
Send your confidential reports on structural safety issues to CROSS.
Masonry bridge assessment course'
I’m running day courses on masonry bridge assessment through Obvis Ltd. Check the events page for upcoming dates (dates in Scotland just added) or ask about in house options.
Notable failures
Barrow on Soar
In 2016, a wingwall and spandrel wall of an overline bridge collapsed onto live rail. The collapse was triggered by coring work above, but there was considerable evidence of prior deterioration.
Eastham Bridge
Eastham Bridge collapsed into the river. The bridge was under no live load at the time - but two minibuses of schoolchildren were approaching the bridge. River flow was low at the time, so any scour damage took place some months prior at least. It seems unlikely that there was no detectable evidence of distress prior to collapse.
BBC Article indicates scour as cause, council promises report, but it was never released.
Our 3D model, photos collected from 5 locations outside the heras fence using a camera on a long telescopic pole. Models like this are a vital element of proper evidence gathering after failures.
Nine Elms
On Christmas Day 2020, track renewal work was taking place on this viaduct. A vehicle movement triggered a spandrel wall collapse. Around 80m of wall fell.
An internal NR investigation was undertaken but not published. ORR annual reports mention only vegetation management as a relevant issue. But the nature of the failure makes clear that a fracture existed down through the middle of the spandrel wall before the triggering event. That defect may exist in some or many locations over the network.
Had this incident happened on another weekend, in a different location, it could have resulted in dozens of deaths.
Carron Water
Near the site of the tragic Stonehaven derailment. Track vertical profile had been raised progressively over the Carron Water bridge, until it was close to top of parapet level, with no modification of the parapets in their new role as retaining walls. The failure was spotted by a train driver, who reported it as an embankment failure.
Yarnton Road Bridge
Wingwall collapsed February 2023.
Nuneham Viaduct
Subsidence at the abutment of Nuneham Viaduct led to a total closure of the railway between Didcot and Oxford for several weeks in the spring of 2023. The project to replace the abutment was spectacular, but the emergency work caused major disruption not only to passengers and freight but also to Network Rail, who had to divert massive resources from other important work.
The question must be asked whether this should have been an emergency. The answer may be that this was unavoidable, but an detailed investigation of the history was needed.
Importantly, though the earliest date mentioned in press reports for when concern about this movement started seems to be spring 2022, photos posted to LinkedIn at around that time show clearly that movement had been ongoing, probably for decades.
Plessey Viaduct
Another failure during construction. Part of the wingwall of Plessey Viaduct collapsed during track renewal. Photos were posted on social media soon afterwards.