Tunnellers ask what about the radioactive waste?

An interesting article from the tunnelling industry experts.

At a meeting lecture of the British Tunnelling Society last month (October 2014), Professor Rory Mortimore of Brighton University, as a leading geologist with specialist knowledge of chalk geology and Managing Director of ChalkRock Ltd, provided further insightful information for the spiralling costs above the initial construction estimates.

According to Mortimore, the preliminary design and cost estimate of the tunnel in the late 1990s was established before a detailed investigation of the geology had been carried out. The assumption, he reported to the BTS audience, was that the chalk geology of the Stonehenge area was same as other familiar chalk deposits in the UK; but in reality, as revealed by the detailed site and ground investigation studies, it is significantly different and complex.

“The big surprise,” said Mortimore, “was discovery that the geology on the tunnel route contains a large deposit of phosphatic chalks which contain weak and poorly banded sand and silt layers and a high register of radon radiation. Such a large deposit of phosphatic chalks were unknown in Wiltshire and, indeed, in Europe and their impact on the proposed tunnel project were profound.”

When the site investigation programme began, the prime objective was to know how extensive is the 15m thick layer of phosphatic chalk, and to investigate how it was formed. Following that, the impact of the engineering properties and behaviours of the deposits had to be incorporated into the project estimates.

“As a tunnelling medium, the weak chalk, with its poorly banded layers of sand and silt presented the potential of loose running ground in the face, which was not favourable for the assumed open face NATM or sequential face excavation method, similar to the now completed twin-tube highway tunnel for the A3 route at Hindhead in Surrey that was being developed at the same time,” said Mortimore. “A tunnelling method that provided positive face support would be required to reduce construction risk and this increased the cost of the tunnelling operation.”

Another aspect that increased the estimated cost of the project was the special handling required for the radon-contaminated tunnel material and the potential of working in the material to cause phosphate contamination of the groundwater. “Disposing of radon contaminated phosphatic chalk in a landfill presented major concerns and special handling of groundwater and construction wastewater added to the tunnelling and construction cost estimates,” said Mortimore.

More at http://www.tunneltalk.com/UK-21Nov2014-Stonehenge-TBM-bored-road-traffic-tunnel-revived.php

Thanks to Nettie for the link.

The Stonehenge Tunnel Option Videos

A303 Stonehenge southern bypass option - https://www.youtube.com/watch?v=HaTYviSTSfk

A303 Stonehenge southern bypass option and Stonehenge in the distance - the solstitial alignment is marked with an arrow.





A303 Stonehenge northern bypass option - https://www.youtube.com/watch?v=MRGHZ9gRf-E

A303 Stonehenge northern bypass option and Stonehenge in the distance - the solstitial alignment is marked with an arrow.

Click pictures to embiggen them.

(Both videos are on YouTube with the warning "This video is unlisted. Be considerate and think twice before sharing." I have done so.)

The Stonehenge Solstitial Alignment and the Tunnel Proposal

From the Highways England video https://www.youtube.com/watch?v=ZapaIn_ZI6M I have grabbed a screen and overlain the narrowest possible interpretation of the solstitial alignment view that UNESCO says should be protected from any building. I would argue that the sightline should be at least from the width of the monument (the station stones are also markers of the alignment) and by any measure of sanity a lot wider than that. It shows it is not just road lighting we need to worry about it is also vehicle headlights.

Highways England consultation page about the Stonehenge Tunnel for more details and to send them feedback.


From UNESCO's Full Description (IAU Extended Case Study format): Stonehenge World Heritage Property, United Kingdom

A retrospective Statement of Outstanding Universal Value (SOUV) was prepared for the Property by the State Party in 2011 and has been approved by UNESCO. The relevant parts of that SOUV in relation to astronomy are quoted here:

Statement of Significance

The Stonehenge, Avebury and Associated Sites WHP is internationally important for its complexes of outstanding prehistoric monuments…

They provide an insight into the mortuary and ceremonial practices of the period, and are evidence of prehistoric technology, architecture and astronomy…

The complexes of monuments at Stonehenge and Avebury provide an exceptional insight into the funerary and ceremonial practices in Britain in the Neolithic and Bronze Age. Together with their settings and associated sites, they form landscapes without parallel.

The design, position and inter-relationship of the monuments and sites are evidence of a wealthy and highly organised prehistoric society able to impose its concepts on the environment. An outstanding example is the alignment of the Stonehenge Avenue (probably a processional route) and Stonehenge stone circle on the axis of the midsummer sunrise and midwinter sunset, indicating their ceremonial and astronomical character…


UNESCO’s Astronomy and World Heritage Initiative adds: "Assuming that these were once largely clear in the Neolithic and Bronze Ages, it is important to try and ensure that the sightlines are as clear as possible today. All plans should ensure that no further development takes place along them."

Stonehenge and Avebury World Heritage Site Management Plan 2015 lays out various policies including:

Policy 3c – Maintain and enhance the setting of monuments and sites in the landscape and their interrelationships and astronomical alignments with particular attention given to achieving an appropriate landscape setting for the monuments and the WHS itself

Fatal Flaw of the Stonehenge Tunnel Technical Assesment

Highways England have commendably included a mass of technical documents on their consultation page about the Stonehenge Tunnel (Do visit it, read it and leave feedback). They include the technical reports and particularly in TAR appendix G and H they score their proposals against the various aims and policies of the stakeholders.

I have read and searched as thoroughly as I have been able to in the limited time I have had these documents and I have failed to find where they have scored their proposals against two key policies. There is a thin gloss over a generalised Policy 3 from the WHS management plan but it fails to discuss the meat of Policy 3c (see below) and I can find no reference at all to UNESCO's Statement of Outstanding Universal Value which discusses the astronomy of the WHS (also below).

This oversight is so egregious that it invalidates the whole technical assessment, it needs to be redone.

Placing a tunnel portal directly on the most important astronomical alignment of Stonehenge fails these policies so badly that it draws the whole plan into doubt.

It is a pity that the Highway engineers didn't take dear Oscar's advice and rise up from the gutters and look at the stars.

From Full Description (IAU Extended Case Study format): Stonehenge World Heritage Property, United Kingdom

A retrospective Statement of Outstanding Universal Value (SOUV) was prepared for the Property by the State Party in 2011 and has been approved by UNESCO. The relevant parts of that SOUV in relation to astronomy are quoted here:

Statement of Significance

The Stonehenge, Avebury and Associated Sites WHP is internationally important for its complexes of outstanding prehistoric monuments…

They provide an insight into the mortuary and ceremonial practices of the period, and are evidence of prehistoric technology, architecture and astronomy…

The complexes of monuments at Stonehenge and Avebury provide an exceptional insight into the funerary and ceremonial practices in Britain in the Neolithic and Bronze Age. Together with their settings and associated sites, they form landscapes without parallel.

The design, position and inter-relationship of the monuments and sites are evidence of a wealthy and highly organised prehistoric society able to impose its concepts on the environment. An outstanding example is the alignment of the Stonehenge Avenue (probably a processional route) and Stonehenge stone circle on the axis of the midsummer sunrise and midwinter sunset, indicating their ceremonial and astronomical character…


UNESCO’s Astronomy and World Heritage Initiative adds: "Assuming that these were once largely clear in the Neolithic and Bronze Ages, it is important to try and ensure that the sightlines are as clear as possible today. All plans should ensure that no further development takes place along them."

Stonehenge and Avebury World Heritage Site Management Plan 2015 lays out various policies including:

Policy 3c – Maintain and enhance the setting of monuments and sites in the landscape and their interrelationships and astronomical alignments with particular attention given to achieving an appropriate landscape setting for the monuments and the WHS itself

What UNESCO actually says about the Stonehenge Tunnel Threat to The Winter Solstice Sunset

Full Description (IAU Extended Case Study format): Stonehenge World Heritage Property, United Kingdom

(Extracts from the document linked above)

..One of the most important features of Stonehenge – one that has been recognised since the 18th century when it was noted by the antiquarian William Stukeley – is that its principal axis of symmetry is aligned upon winter solstice (“midwinter”) sunset in one direction and summer solstice (“midsummer”) sunrise in the other...

Stonehenge WHP can and should be seen within a regional context of sites in the Neolithic and Bronze Age in north-west Europe that have astronomical alignments. These include monuments such as the Newgrange passage tomb, part of the Brú na Bóinne—Archaeological Ensemble of the Bend of the Boyne WHP, and various stone circles and monuments. All seem to have had some sort of funerary or ceremonial function, although astronomical practices in domestic contexts are also noted on occasion.

The monuments of the Stonehenge WHP provide the earliest evidence in Britain or Ireland of a consistent local practice of aligning monuments with some precision upon sunrise or sunset around the solstices. This is in contrast, for example, to the solstitial orientation of Newgrange, a “one-off” alignment among the Boyne Valley tombs; to the very broad pattern of orientation clustered around the intercardinal directions observed among Neolithic tombs and houses in the Orkney Islands; and to evidence that Early Neolithic long barrows in the Salisbury Plain area, in the vicinity of Stonehenge—which preceded the construction of the Stonehenge stone circle by about a millennium—followed a broad pattern of orientation within the sun-rising/sun-climbing arcs, between north-east and south...

In prehistory, one or more observers would probably have stood at an appropriate point and viewed the sun or moon appearing or disappearing behind a distant horizon at specific times of the year. Thus, clear and unobstructed sightlines and horizons are important to aid our understanding of how these monuments functioned...

There is a growing consensus that the midwinter sightline was more important than the midsummer one. Today the integrity of this sightline, and its intermediate ridge lines and final horizon, is marred. Looking out from Stonehenge, the first problem is the A303 (0.5 km), which runs relatively close to the monument, and presents a considerable visual and noise intrusion to this alignment. Moving further south-west, the round barrow known as the Sun Barrow—which is on the alignment and on the Normanton Down ridge line—is intact (0.9 km), but the sightline then quickly runs into the plantation known as Normanton Gorse (1.1 km), which obscures it. Still further south-west is another plantation known as The Diamond (2.2 km), before the alignment continues towards the place that would form the visible horizon from Stonehenge in the absence of intervening vegetation, at Oatlands Hill to the west of the A360 road (and outside the WHP) (4.4 km). This horizon is also obscured by yet another plantation, at The Park. The sightline probably ends at the site of a much later Iron-Age/Romano-British settlement. It is difficult to determine the exact place because the various obstructions mean that we must rely upon computer modelling.

The Stonehenge Avenue looking south-west (midwinter sunset) shares the same alignment, and the same issues apply regarding its integrity. On the initial approach towards Stonehenge along the Avenue from the “elbow” at Stonehenge Bottom, Stonehenge itself forms the horizon; the more distant landscape only appears during the final stages of the approach.


A retrospective Statement of Outstanding Universal Value (SOUV) was prepared for the Property by the State Party in 2011 and has been approved by UNESCO. The relevant parts of that SOUV in relation to astronomy are quoted here:

Statement of Significance

The Stonehenge, Avebury and Associated Sites WHP is internationally important for its complexes of outstanding prehistoric monuments…

They provide an insight into the mortuary and ceremonial practices of the period, and are evidence of prehistoric technology, architecture and astronomy…

The complexes of monuments at Stonehenge and Avebury provide an exceptional insight into the funerary and ceremonial practices in Britain in the Neolithic and Bronze Age. Together with their settings and associated sites, they form landscapes without parallel.

The design, position and inter-relationship of the monuments and sites are evidence of a wealthy and highly organised prehistoric society able to impose its concepts on the environment. An outstanding example is the alignment of the Stonehenge Avenue (probably a processional route) and Stonehenge stone circle on the axis of the midsummer sunrise and midwinter sunset, indicating their ceremonial and astronomical character…


Assuming that these were once largely clear in the Neolithic and Bronze Ages, it is important to try and ensure that the sightlines are as clear as possible today. All plans should ensure that no further planting or development takes place along them.

The Threat To The Winter Solstice Sunset at Stonehenge From The Tunnel

It is important to point out that the position of the tunnel portal is still officially under consultation but the only tunnel plan offered has its western portal in line with the winter solstice sunset as seen from Stonehenge. Mike Pitts says of this plan that it: "scored highly on its OUV impact"... "OUV. That’s “outstanding universal value”, a concept that is taken very seriously in assessing any changes in the landscape. How would a tunnel portal so close to the stones affect OUV, bearing in mind floodlights at night (if such things were visible, they’d be a problem all year round, not just on midwinter day)? I’d say very badly."

From Highways England Consultation Booklet 

The OUV component that concerns the sightlines is discussed on the UNESCO page http://www2.astronomicalheritage.net/index.php/show-entity?identity=49&idsubentity=1

The integrity of sightlines within the Stonehenge WHP

In assessing the integrity of these sightlines today, we make the assumption that they were largely kept clear in the Neolithic and Bronze Ages, so that the monuments could be used in the way in which we presume they were used, with the sun or moon rising or setting behind distant horizons visible from the monuments themselves. The sightlines are shown in (this figure).

Astronomical sightlines at Stonehenge World Heritage Site and the surrounding area, with their end-points on horizons. These should be treated as indicative rather than necessarily exact. The WHS area is shaded in yellow. Produced by Nick Hanks, Historic England, February 2015. © Crown Copyright and database right 2015. All rights reserved. Ordnance Survey Licence number 100024900

Sightline from Stonehenge looking southwest (midwinter sunset)

There is a growing consensus that the midwinter sightline was more important than the midsummer one, as discussed above. Today the integrity of this sightline, and its intermediate ridge lines and final horizon, is marred. Looking out from Stonehenge, the first problem is the A303 (0.5 km), which runs relatively close to the monument, and presents a considerable visual and noise intrusion to this alignment. Moving further south-west, the round barrow known as the Sun Barrow—which is on the alignment and on the Normanton Down ridge line—is intact (0.9 km), but the sightline then quickly runs into the plantation known as Normanton Gorse (1.1 km), which obscures it. Still further south-west is another plantation known as The Diamond (2.2 km), before the alignment continues towards the place that would form the visible horizon from Stonehenge in the absence of intervening vegetation, at Oatlands Hill to the west of the A360 road (and outside the WHP) (4.4 km). This horizon is also obscured by yet another plantation, at The Park. The sightline probably ends at the site of a much later Iron-Age/Romano-British settlement. It is difficult to determine the exact place because the various obstructions mean that we must rely upon computer modelling.

As closely as I can I have overlaid the Ordnance Survey map with the position of the portal (marked within a red circle) and the UNESCO Southwest Sightline (thick red line). My calculation is that the centre of the sightline is 60m from the centre of the portal. With the margin of error, the width of the sightline and the size of a tunnel portal I would say that is pretty close to the portal being on the sightline, too close for my liking.

Click pictures to enlarge.

It is worth pointing out that it isn't just the central line at Stonehenge. The Station Stones also align to the midwinter sunset so one could fairly consider the solstitial line at the monument to be nearly 100m wide.

A303 Stonehenge plans published

Plans for tunnel under Stonehenge, part of roads package to cut congestion in the south-west.


Department for Transport, Highways England and The Rt Hon Chris Grayling MP
First published:

12 January 2017

A303 past Stonehenge.

Major plans to transform the A303 as part of a £2 billion investment in the south-west, which will see the construction of a tunnel at the historic Stonehenge site, have today (12 January 2016) been unveiled by Transport Secretary Chris Grayling.

The upgrade will develop the A303 corridor into a high quality, high performing route linking the M3 in the south-east and the M5 in the south-west, improving journeys for millions of people.
Secretary of State for Transport Chris Grayling said:

This government is taking the big decisions for Britain’s future, underlined by our record £15 billion funding for road schemes.

This major investment in the south-west will transform the A303 and benefit those locally by cutting congestion and improving journey times. It will also boost the economy, linking people with jobs and businesses with customers - driving forward our agenda to build a country that works for everyone and not just the privileged few.

Drivers, hauliers, residents and other road users are being invited to have their say on the proposal to upgrade a seven-mile single carriageway stretch of the A303 near Stonehenge in Wiltshire into a dual carriageway.

The single carriageway section of the A303 currently runs alongside the stones and the proposed option is to construct a 1.8 mile dual carriageway tunnel to improve journey times, remove the sight and sound of traffic and enhance the world heritage site.

The 2014 Road investment strategy committed to upgrading all remaining sections of the A303 between the M3 and M5 to dual carriageway standard, starting with 3 schemes:
at Stonehenge
between Sparkford and Ilchester
between Taunton and Southfields

Highways England Chief Executive Jim O’Sullivan said:

We are delivering the biggest investment programme in our roads in a generation.

Our plans for the A303 recognise the national importance of the route and these improvements will bring real benefit to the region and local communities.

The public exhibitions will provide an excellent opportunity to explain further our plans and to hear feedback from stakeholders on our proposals to deliver the scheme.

The Stonehenge consultation launches on 12 January and will offer the public the chance to view the proposals and meet the project team. Public consultation for the latter 2 projects will follow in due course.

The Stonehenge scheme proposals also include a bypass for the village of Winterbourne Stoke and improvements to existing junctions between the A303 and the intersecting A345 and A360 north-south roads.

The consultation runs between 12 January and 5 March. Following the consultation the preferred route will be announced later in 2017 and is subject to the completion of statutory procedures for development consent.

Public exhibitions will be staged at the following locations:
The Manor Barn, Manor House, Winterbourne Stoke on Saturday, 14 January (11am-5pm)
Antrobus House, Amesbury, on Wednesday, 18 January (2pm-8pm)
Shrewton Village Hall, The Hollow, Shrewton, on Friday, 20 January (5pm-9pm)
Avon Valley College, Recreation Road, Durrington, on Saturday 21 January (11am-5pm)
Larkhill Primary School, Wilson Road, Larkhill, Tuesday, 24 January (5pm-9pm)
The Manor Barn, Manor House, Winterbourne Stoke on Friday, 27 January (2pm-8pm)
Salisbury Guildhall, The Market Place, Salisbury, on Saturday 28 January (11am-5pm)
Grove Hall, Church Street, Mere, near Warminster, on Saturday 4 February (11am-5pm)
Society of Antiquaries, Burlington House, Piccadilly, London, on Monday 6 February (2pm-8pm)
Antrobus House, Amesbury, Wednesday, 8 February (2pm-8pm)

Following the consultation, the preferred route will be announced later in 2017.

During the public consultation, more details and a questionnaire will also be available at www.highways.gov.uk/a303stonehenge/consultation

For concerns about the effect of the tunnel on the Winter Solstice Sunset sightline see;http://www.sarsen.org/2017/01/the-threat-to-winter-solstice-sunset-at.html


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