Digging up the past


On the face of it, the construction industry and the archaeological profession would appear to have very little in common beyond a shared tendency to dig holes in the ground. After all, construction’s all about progress and development whereas archaeology is focused entirely on what has gone before.

But as many recent discoveries have demonstrated, these two activities are intimately connected – to the extent that the vast majority of archaeological discoveries in the UK today occur on construction sites. Indeed, archaeologists are often members of the project team, especially on major infrastructure projects.

This article was first published in the March 2022 issue of The Construction Index Magazine.  Sign up online 

It wasn’t always like this, though. In the bad old days, 40 or more years ago, the discovery of a few mediaeval coins or a Roman mosaic was about as welcome on a construction site as a colony of great crested newts or rare orchids. In other words, it meant a costly and disruptive intrusion into the build programme.

“It’s not like that any more,” says Andy Crockett, A303 Stonehenge project director with Salisbury-based Wessex Archaeology. “Any confrontation between contractors and archaeologists is long gone; it’s a much more collaborative relationship today,” he adds.

With about 40 years’ experience, Crockett can remember when the relationship was more adversarial. “Access to the site was in the gift of the developer and there was always a degree of suspicion on both sides – we regarded each other as the enemy,” he admits.

That changed fundamentally in 1990 with the introduction of Planning Policy Guidance 16: Archaeology and Planning (PPG16) which advised planning authorities that the presence of archaeological remains should be a ‘material consideration’ in applications for new development.

Under PPG16 (since replaced by the National Planning Policy Framework) the developer became responsible for funding archaeological investigations as an extension of the ‘polluter pays’ principal – in other words, if you are to profit from a development you must pay to investigate, preserve and record any archaeological discoveries that arise.

Although the ball was now firmly in the developer’s court, the new regime worked well for all stakeholders and the archaeologist became part of the project team, rather than a third party with its own agenda.

“Now, right up front, the archaeologist will know if their client has any archaeological constraints before work starts,” says Crockett. “That means the developer can plan for it and budget for it.”

According to Crockett, it is now very rare for archaeology to cause major delays to a project and, in many cases, the archaeological element provides an invaluable opportunity for publicity and positive public engagement, not just with the local population but often nationwide.

This is demonstrated nowhere better than on HS2, which has produced a steady stream of significant archaeological finds. Earlier this year, HS2 announced the discovery of a “vast” Roman settlement on the route of the new railway line in south Northamptonshire.

The site at Blackgrounds Farm near the villages of Edgcote and Chipping Warden was once the location of an Iron Age village dating to about 400BC. But the team of archaeologists from Museum of London Archaeology (MOLA) has unearthed a much larger Roman settlement that grew up later on the site.

Artefacts including coins, pottery, glass vessels and jewellery were found, plus several “beautifully preserved” wells and a 10m-wide Roman road – described as “exceptional” in size. Such was the interest generated by the discovery that the site was featured on BBC television’s Digging for Britain series in February.

Assessing the archaeological status of a proposed project is usually the responsibility of the county archaeologist. “Their role is central to the work of archaeological intervention,” says Crockett. “Nearly all county councils have an in-house archaeologist, and although I wouldn’t say they were a dying breed, funding for these departments is constantly under pressure and they’re all struggling”.

The archaeology starts right at the beginning of the planning process, says Crockett. “Say it’s a new road: National Highways will develop a planning proposal and apply for a development consent form – and pretty much the first person to be consulted on that will be the county archaeologist.

“They will advise on any preparatory work that’s required – identifying any scheduled monuments, historic buildings and so on – and will produce a list of recommendations.

“Next comes the environmental impact assessment, which also includes any archaeological considerations. After that the client or main contractor will go out to tender for an archaeological contractor,” he says.

The archaeologist usually starts with desk-based work, says Crockett. This detailed study of maps, documents and local records will yield important information about the likelihood of archaeological discoveries and their possible location.

Armed with this data, the archaeological team will go out on site and conduct a targeted evaluation by digging trial trenches and test pits. “The county archaeologist will typically adopt a sample level covering roughly two to five percent of the surface area of the proposed development. Then we will go out and dig buckets’-width trial trenches in selected positions across the site,” says Crockett.

“If your geophysical survey found any anomalies you’d put a trial trench across that area to find out what’s underneath. If you find something of interest, there’s the opportunity to hand-excavate for a closer look – though we try to avoid a trial trench becoming a mini-excavation,” he adds.

Very often, the items of interest would be overlooked by a casual observer. It might be just a change in the colour of the soil, indicating a back-filled ditch marking an enclosure, or building foundations. “You’re looking for subtle differences in soil structure – for example between the natural undisturbed subsoil and an area in which the soil has been mixed with other materials,” says Crockett.

Of course, occasionally something more interesting is unearthed: “It you find any human remains, you can’t keep digging,” Crockett says. “The Burial Act makes it illegal to disturb a grave, so you have to stop and notify the authorities straight away. Luckily, most archaeologists can tell human bones from animal remains – there’s no mistaking a human femur.”

Even if nothing of great intrinsic significance is found, these preliminary trial trenches can yield vital clues as to what might be encountered in other parts of the site. “If I’m finding tiny fragments of Romano-British pottery that have been extensively broken and abraded I know that I’m probably not close to a settlement,” says Crockett; “It’s probably night-soil taken from a midden and scattered on the fields as fertiliser.

“But if I’m finding fresh, large chunks of pottery I know I’m more likely to be closer to a settlement or dwelling.”

Not every site results in a major archaeological dig, of course, and Crockett is keen to stress that this is not the main objective. “The overarching consideration is preservation in-situ,” he says. “We won’t dig if we don’t have to because it’s always best to leave something undisturbed if possible.”

The archaeological contractor’s role is therefore to carry out a thorough investigation for its client. “We’re a commercial business working under contract to the developer or contractor. We have a commercial interest and our job is to report our findings and advise,” explains Crockett.

“All the decisions – about whether or not construction work can go ahead – are made by the county archaeologist. They sign it off; it’s not our call,” he says.

As his job title indicates, Crockett is currently focused entirely on Stonehenge and the proposed tunnel. “The original consent order was quashed last year, but National Highways is resolute and keen for us to continue our work,” he says. However, no more digging can continue on site until legal challenges by campaign groups have been resolved.

Crockett completed the evaluation work on the project in 2019, but given the scale of the site and its status as a UNESCO World Heritage site, Wessex Archaeology has plenty of work to do preparing method statements, heritage management plans and carrying out other due diligence.

Rather surprisingly, Crockett isn’t expecting any major discoveries at Stonehenge. “And that’s a good thing,” he says. “We know we’ll find archaeological remains, mainly isolated early to late neolithic graves and Beaker burials; we’re almost certain to find a handful of those – in fact we’ve found a few already,” he says.

After four decades in the profession, the Stonehenge tunnel will probably be Andy Crockett’s last major contract. “Some of my first assignments were on Stonehenge, so if and when this goes ahead it will be quite fitting,” he says. “It’s going to bookend my career”.

This article was first published in the March 2022 issue of The Construction Index Magazine.  Sign up online 

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