Why demolition and infilling are blunt weapons in the management of historic structures

The demolition of Brunel's bridge over the GWR at Iver took place in 2014. It was not possible to fit the overhead lines beneath the arches, so a new bridge was required. By the following morning, most of the bridge was gone. The remains of the pillars have been incorporated into the new bridge.

1 Introduction
2 Victorian engineering - liabilities or opportunities?
3 The impact of infilling bridges
4 Risk to public safety?
5 The role of historic structures in future transport plans
6 Related articles on Designing Buildings Wiki

[edit] Introduction

Thousands of old bridges, viaducts and tunnels exist in the UK - all of them liabilities in their redundant state. But many await conversion into assets that will make a positive difference, says campaigning alliance The HRE Group.

Scattered across our nation are relics of the transport revolution brought by the railway in the 19th century and lost to another - driven by the motorcar - in the 20th. Fifty years ago, the notion that we might eventually reopen railways was fanciful, but the climate is changing - literally and metaphorically.

And then there’s walking and cycling, which saw a huge uptake during the first pandemic lockdown in March 2020, as we embraced clean air and green space. The Government is beginning to recognise the benefits offered by active travel and match them with proportionate investment in the safe, high-quality infrastructure needed to encourage more of us onto our feet and bikes.

[edit] Victorian engineering - liabilities or opportunities?

All this has created a different context through which to view our network of disused railways and the Victorian engineering feats that carry them through the landscape. There are thousands of old bridges, viaducts and tunnels out there - all of them liabilities in their redundant state, but many await conversion into assets that will make a positive difference.

The greatest single collection of structures comprises the Historical Railways Estate (HRE) - owned by the Department for Transport and managed on its behalf by Highways England (which became National Highways in August 2021).

In 2016, the company’s draft Strategic Plan for the HRE revealed an intention to demolish up to 480 structures before 2030, “to significantly reduce the level of liability and risk”. Beyond this, dozens of bridges and tunnels are earmarked for infilling.

If fully implemented, the impact will be far reaching, with 10 proposed cycle paths and bridleways blocked. Extensions to heritage lines in Angus and Norfolk would also be affected, together with four railway re-openings. (The HRE Group gathered information about these through three weeks of research from local sources.)

[edit] The impact of infilling bridges

In what some might describe as an egregious act of vandalism, May/June 2021 brought the infilling of a delightful masonry arched bridge, scarring the Cumbrian countryside. It was needed for a connection between two heritage railways, neither of whom was consulted. Photos of concrete spewing from beneath the stonework looked particularly gruesome.

Back in January 2021, a Highways England spokesperson told media outlets that “around 200 of the public road bridges managed by HE/HRE have failed their most recent structural assessment (BD21) but haven’t had any [weight] restrictions implemented. Therefore, our planned infilling is the safest and most appropriate option and will maintain access across the structure.”

This was misleading, as 55 (48%) of the 115 bridges then slated for infilling were not among these “around 200” structures. The real figure was 169. And 14 of these *did* have weight restrictions. And dating from pre-1922, they were neither expected nor required to pass BD21 assessments; a legacy standard, BE4, applies. But apart from that.

The last five infilling schemes undertaken by Highways England cost an average of £145,000; its Strategic Plan indicates that £25,000 is spent on repairs and assessments to each HRE bridge every 10 years, so no cost savings will typically accrue from infilling for 58 years.

[edit] Risk to public safety?

Due process offers salvation, of course: campaigners can simply object to the relevant planning application when it appears. And with many of the disused railways spanned by the threatened bridges safeguarded under policies adopted by the local councils, the prospect of rejection must surely be high.

Except, in all but 10 cases, Highways England was attempting to drive through the schemes under permitted development powers, like it or lump it. Democratic process was thus circumvented and undermined.

On 10 September 2020, Jacobs, HE’s agent, sent 34 permitted development (Class Q) notification letters to local authorities asserting that the structures to which they referred represent “an ongoing and increasing risk to public safety” and that action was being taken “to prevent an emergency arising”.

These powers obligate Highways England to return any affected structure to its previous state within six months of work starting, unless planners consent in writing to the infill being retained. This didn’t deter them, however.

You might imagine that contractors up and down the country were immediately mobilised to close roads and shore-up these decrepit bridges before catastrophic failure claimed the lives of unsuspecting motorists. But almost a year later, according to our local sources, work has been reported at only three of these structures.

The truth is that infilling and demolition are blunt, destructive weapons in Highways England’s armoury of asset management options. Permitted development powers are being abused to avoid scrutiny and potential obstruction through the planning process. There are no emergencies - that’s simply a sham.

[edit] The role of historic structures in future transport plans

Nobody is asserting that we must keep everything Victorian railway engineers ever gifted us through their courage, grit and ambition. About one-third of the structures in Highways England’s sights have no realistic value and can probably be lost without impacting future transport schemes.

But there’s a right way to do this and a wrong way: blindly putting structures beyond use without considering their heritage value, community aspirations, environmental blight and ecological impacts constitutes the latter. So does the undermining of democracy.

Targeted investments and a collaborative approach have the potential to deliver transformational new roles for many of the at-risk structures, helping to promote the Government’s aspirations for an active travel revolution and improved community connections.

The consensus amongst stakeholders is that a cultural blockage within the DfT is conspiring with Highways England’s questionable fitness and risk-averse mindset to consign the Historical Railways Estate to a continued and unproductive decline. This approach might have felt at home in the 1970s, but it has no place in 2021.

More than 16,600 people have so far expressed their opposition by signing a petition challenging the infillings and demolitions. As a result of vocal criticism and political interventions, the works programme was recently placed on hold pending the establishment of “a formalised framework and engagement process”, which should be in place by autumn 2021.

If we’re really going to ‘build back better’ and level up after the pandemic, we need to make the most of every opportunity presented by our existing infrastructure. Public bodies needs to play their part with determination and enthusiasm.

This article originally appeared on the ICE Community Blog portion of the ICE website. It was written by Graeme Bickerdike, member of campaigning alliance The HRE Group and published on 27 August 2021.

--Institution of Civil Engineers