Biodiversity and Bomb Craters

The Kilvey bombed landscape is unique in Wales, although bombs were dropped across the Welsh ports between 1940 and 1943, ther survival of any traces is rare. Several shrapnel-scarred buildings remain in Swansea, and a similar situation exists in other European towns and cities. What is unique in Wales is the survival of a landscape with craters that has been allowed to recover or develop naturally.

A look at the biodiversity contribution of the World War Two bomb craters on Cilfái.

I’ll be leading a couple of walks up the top of the hill soon. This year, I’m intent on looking at biodiversity and heritage. The bomb-damaged landscape of Kilvey Hill is now 84 years old, and a lot of it has survived or avoided being bulldozed, as often happens. Ironically, the heritage landscape of the Hill may soon be destroyed by Swansea Council as part of their Skyline tourism obsession.

The Kilvey bombed landscape is unique in Wales, although bombs were dropped across the Welsh ports between 1940 and 1943, the survival of any traces is rare. Several shrapnel-scarred buildings remain in Swansea, and a similar situation exists in other European towns and cities. What is unique in Wales is the survival of a landscape with craters that has been allowed to recover or develop naturally.

Many of you will know of my interest in bombsite botany via my lectures and articles, and one of the chapters in my book on the Three-Nights’ Blitz. Although formed in horrible acts of violence, the Kilvey bomb craters have been transformed by nature into essential wildlife refugia. Some hold small ponds, others are havens of warmer temperatures and protection from the wind, or even fire. The combustion of chemical explosives would have made the craters poisonous after their creation, and of course, the land is peppered with bomb fragments, which have become part of the archaeology of the hill. Nearly a century later, the craters have taken on a new role as centres of plant and wildlife.

I’ll explore this incredible mix of heritage and ecology on a couple of walks. I’ll advertise via Eventbrite, and I’ll let you know here as well.

Above: One of the Kilvey bomb craters with a small mire. June 2025.
A photo-generated 3D model of one of the Kilvey bomb craters, March 2025.

U-boats in Swansea Bay and Bristol Channel

Starting the new book project. I initially looked at the war diaries of Bristol Channel U-boats back in the 1990s. Research is now easier as more primary records have been released by US archives, at least until the latest President Trump directives close everything down. Modern technology in GIS and GPS has made map research much easier, and I am busy tracking down the original locations of magnetic mines originally planted in Swansea Bay and around the Scarweather Lightship. There have already been a few surprises as the mapping throws up all sorts of questions and new insights into the highly technical war of minelaying and minesweeping in the Bristol Channel.

Starting the new book project. I initially looked at the war diaries of Bristol Channel U-boats back in the 1990s. Research is now easier as more primary records have been released by US archives, at least until the latest President Trump directives close everything down. Modern technology in GIS and GPS has made map research much easier, and I am busy tracking down the original locations of magnetic mines originally planted in Swansea Bay and around the Scarweather Lightship. There have already been a few surprises as the mapping throws up all sorts of questions and new insights into the highly technical war of minelaying and minesweeping in the Bristol Channel.

The war against the U-boats is a complex subject to research thoroughly. There was considerable secrecy on both sides, and very often, the knowledge gap has been filled with wild speculation and inaccurate writing. This means I’ve had to reject a lot of secondary sources that continue to repeat what I’ve learned to call the ‘BBC History’ approach of ruthlessly clever Germans versus plucky eccentric Englishmen. There is also a surprising amount of rivalry and bias between British and US naval sources, both in the 1940s and in the present day. Again, I’ve learned to be scrupulous in testing opinions by viewing primary sources rather than derived history, often from writers who have not worked in the original German language sources.

Above: U28 was one of the Bristol Channel U-boats. This is the boat as she looked just before the war began in September 1939.

Some initial work was included as an Annexe in ‘Eye of the Eagle’ where I looked at the war diary of U32 as it laid magnetic mines near the Scarweather Lightship in 1939. The new work looks at all the other U-boats that came into Swansea Bay in the early years of the war. Again, it reinforces the crucial role Swansea had in the minds of the German naval staff.

Above: An extract from a U-boat war diary, with my translation. From the Eye of the Eagle book.

The Foxhole Coal Staithes, Swansea

The Foxhole River Staithes are a set of enigmatic structures on the banks of the River Tawe near the remains of the White Rick Copper Works. Although now hidden by trees and slowly deteriorating, they were once the centre of the incredible coal industry that dominated Kilvey and Foxhole in Swansea. This book describes the history of coal in early Swansea and explains the significance of the last remaining structures of the coal industry of early Swansea before the arrival of copper smelting in the 1730s

I completed my cheap photography project last month, and added it to my early Swansea coal history book.

The history of Swansea coal is being lost amongst all the noise and gravy train funding for the Hafod/Morfa Copperopolis story. My work on Swansea coal is meant to redress some of that imbalance and cast new light on a part of the Lower Swansea Valley that isn’t considered important.

The photogrammetry was a great success, completed for a few hundred pounds rather than the thousands claimed by local firms. The constraints were to use second-hand cameras and computers, and to provide imagery of a quality and level of detail that would prove useful. No drones were used as we found that they were adding a layer of costs and complexity that was distorting the value of what should be an extremely cheap and quick process.

After discussing the protocols with a couple of BIM colleagues, I looked at the protocols described in this 2011 paper (listed below). Despite being a little older than the average BIM work these days, the workflows were good, easily replicated, and I could learn how to use simpler, older cameras for the imagery.

There was a series of trials of various landscape and heritage features, ranging from riverside bollards, dock walls, and larger landscape features such as bomb craters and threatened landscapes. The larger subjects needed drone input, and so they were discarded, although some beneficial results were obtained for researching biodiversity and small-scale features which I’ll follow up in a later project.

The study subjects were the Foxhole River Staithes, which were of good size (typically about 8m wide, 3m high) and interesting construction. The photographic survey took just over three days, with about four thousand images collected. Office processing of the imagery took about three days.

Above: An ‘aerial’ view of one of the Staithe Structures reconstituted from ground photogrammetry, no drones, merely ground camera work.
Above: Another view of Foxhole Structure B. A series of stone retaining walls that originally had timber decking, allowing the loading of coal into various-sized river vessels. Built in the early eighteenth century, probably before extensive copper smelting had begun.
Above: Some of the mines and coal veins of early Swansea, discussed in the book.

The photogrammetry was included in a book giving a brief history of coal in Swansea and the significance of the Foxhole area in pre-industrial Swansea.

Fai, Stephen & Graham, Katie & Duckworth, Todd & Wood, Nevil & Attar, Ramtin. (2011). Building Information Modeling and Heritage Documentation.

“The Foxhole River Staithes are a set of enigmatic structures on the banks of the River Tawe near the remains of the White Rick Copper Works. Although now hidden by trees and slowly deteriorating, they were once the centre of the incredible coal industry that dominated Kilvey and Foxhole in Swansea. This book describes the history of coal in early Swansea and explains the significance of the last remaining structures of the coal industry of early Swansea before the arrival of copper smelting in the 1730s. The story of the coal mines of Swansea, the coal export trade and the ships that visited eighteenth-century Swansea are all described. The book also includes the results of photogrammetric surveys of the surviving structures to give the story of the true significance of the Foxhole Staithes and their place in Welsh history.”

Foxhole River Staithes and Swansea Coal 1300-1840https://www.lulu.com/shop/nigel-a-robins/foxhole-river-staithes-and-swansea-coal-1300-1840/paperback/product-656z44z.html?page=1&pageSize=4

Details

Publication Date Apr 19, 2025

Language English

ISBN9781739353353

Category History

CopyrightAll Rights Reserved – Standard Copyright License Contributors

By (author): Nigel A Robins

Specifications

Pages 104, Binding Type Paperback, Perfect Bound, Interior Color Color

Dimensions US Trade (6 x 9 in / 152 x 229 mm)

More on Swansea Valley photogrammetry

For many projects in restoration and landscape, there has been a tendency to overemphasise gee-whiz graphics at the cost of scholarly historical analysis. The project here puts the technology back where it belongs, in the background of support for investigation and analysis.

The rapid development and delivery of this project is almost complete. The proof of concept of quick and cheap photogrammetry is complete, and we explored various features of various sizes. Budget constraints in the broader London-based programme meant that the planned exploitation phase won’t take place there. The plan was to explore some large, immoveable sculptures and statues at risk of damage by surrounding building renovation. Instead, I’ll work in South Wales on a series of local history and geography projects.

Costs were remarkably low (which we believed they would be). It is satisfying to use new technologies to reduce costs and fight against the gradual cost inflation and scope creep of using these types of technologies in small history or geography projects. In researching the business case for this, I learned of several local authority projects where high costs for archaeological surveys, often incorporating expensive drone surveys and extraordinary labour costs, skewed project delivery budgets almost to the cancellation of the projects. I experienced the same issues working on the restoration of the Palace of Westminster, where incredible finances and resources were expended on expensive lidar and photogrammetry products that were who;;y unsuitable for the problems and frequently misled managers into thinking that such products were essential elements of the restoration at RIBA Stages 1 and 2 .

For many projects in restoration and landscape, there has been a tendency to overemphasise gee-whiz graphics at the cost of scholarly historical analysis. The project here puts the technology back where it belongs, in the background of support for investigation and analysis.

Above: A test scan of a significant rock exposure on Cilfái Hill in Swansea. Upper Carboniferous Pennant Sandstone with a forty-degree dip north. This is an exposure in an area where William Logan and Henry De la Beche discussed the general stratigraphic layout of the South Wales Coalfield. Some of the exposures have copper nails struck into the rock, which may have been part of Logan’s levelling work in the late 1830s. These exposures are at risk of destruction by Swansea Council’s tourism redevelopment of the area, so it is good to get a good scan of them before they are destroyed.
Above: An old coal loading dock in the Lower Swansea Valley, known as a ‘Staith’. Probably dating from the 1740s, this was built to make loading coal into ships in the river easier. The coal came down the east-side tramways and later the canal. This is a scheduled ancient monument but has been neglected by Swansea Council and is now deteriorating. Ironically, the monument’s destruction has been accelerating because of the encroaching woodland and the dumping of industrial waste. This structure is incredibly rare; there may only be two others in Wales, and they are also in the Lower Swansea Valley. Again, this is a low-cost photogrammetric scan taken as an emergency whilst extensive finances are expended elsewhere in the Valley on Council-led projects.

Costs are kept low by avoiding the use of drone technologies, using older and previously-used professional cameras bought cheaply on Ebay, and new software costing a few hundred Euros.

The next steps are researching the history of coal industry structures in the valley, followed by some investigation of some World War Two remains on Cilfái.

Low cost photogrammetry in the Lower Swansea Valley

The work here was added to original surveys carried out in the 1980s, and a comparison with photographic records allowed a visual check of the structure’s deterioration and environmental changes. A review of the geology of the structure’s building materials could also be carried out, which revealed distinctive contrasts between this structure and other post-1737 structures and walls nearby.

I’m really pleased that this small project is now starting to yield results! The first delivery was a series of scans and interpretations of some rare dock structures on the banks of the River Tawe. Some of the structures are scheduled ancient monuments, but the oldest and rarest are not!

The brief for this structure was a cheap and accurate photogrammetric survey at the lowest cost, allowing for interpretation and enhancing the historical information from earlier work and new research. The requirement was cheap, quick and accurate, which meant no expensive drone or landscape surveys.

Above: An early eighteenth-century coal staith remains in the Swansea Valley.

The work here was added to original surveys carried out in the 1980s, and a comparison with photographic records allowed a visual check of the structure’s deterioration and environmental changes. A review of the geology of the structure’s building materials could also be carried out, which revealed distinctive contrasts between this structure and other post-1737 structures and walls nearby.

There is still much to do, including costing the project and leveraging the technology more effectively on little-known structures in the area.

More photogrammetric research on small landscape features

The concept of quick and cheap photogrammetry is now proven, and simple work like this can be comparable to expensive archaeological surveys, which cost far more, often a hundred times more than current archaeological firms charge.

As I said earlier, the purpose of this project was a proof of concept on using photogrammetry as cheaply as possible to allow quick and accurate reconnaissance and survey of small features that generally would not be investigated or be too expensive to survey using current high-cost photogrammetry, drone and lidar techniques.

This example is a bomb crater on Kilvey Hill. The crater was most likely created in the January 1941 attack on the town. The crater is from a large calibre bomb (possibly 250kg) that has penetrated some way into the soft, marshy ground and then detonated.

In the 84 years since the detonation, the crater has softened with the crater lip mostly eroded. The crater frequently fills with water and has a different botanical nature to the surrounding grassland. This crater is a local biodiversity hotspot, allowing moisture to be present all year round and providing better protection from excessive temperatures. A large pine in the centre of the crater has died providing a reservoir of dead wood.

Above an extract from an initial 3D model of one of the Kilvey bomb craters, 2025.

The concept of quick and cheap photogrammetry is now proven, and simple work like this can be comparable to expensive archaeological surveys, which cost far more, often a hundred times more than current archaeological firms charge.

Using Photogrammetry for our local heritage at White Rock

When I worked on the Palace of Westminster Restoration and Repair programme, photogrammetry and point clouds were absurdly expensive, and R&R was very vulnerable to overspending and out-of-control costs in obtaining basic survey imagery. Equally, archaeology drone surveys seem to be moving in the same direction…expensive and complicated.

Making progress with accessible and cheap photogrammetry for small and very small landscape features. This project is to develop cheap workflows for local authorities and heritage groups to quickly obtain helpful heritage survey information.

Above: Basic scan of a very old riverside bollard that may have had a very surprising history.


When I worked on the Palace of Westminster Restoration and Repair programme, photogrammetry and point clouds were absurdly expensive, and R&R was very vulnerable to overspending and out-of-control costs in obtaining basic survey imagery. Equally, archaeology drone surveys seem to be moving in the same direction…expensive and complicated.


This project uses recycled cameras and computers to bring survey details within the reach of stretched budgets, allow the survey of threatened objects to be quickly documented, and append point cloud information to correct historical details. This allows the heritage information to be prioritised and the technology back where it belongs—in the background.

This riverside bollard was probably installed in the early 1800s and may be a repurposed atmospheric steam engine cylinder from the eighteenth century. The first of a portfolio of artifacts to be surveyed and interpreted as part of a landscape history programme.

Above a 3D model of the bollard. This image is able to contain all the dimensions and historic information within the file. This can be done quickly and cheaply instead of expensive archaeological surveys

Lower Swansea Valley Heritage: Applying new techniques

I’ve got some funding to run a small Heritage BIM project. I’m running a photogrammetry project on a few small and less well-known industrial remains in the Swansea Valley. The proposal is to explore how effective and cost-effective cheap photogrammetry can be in surveying and analysing small structures and supplement statements of significance. With reference to CIDOC and ISO 19650.

I’ve got some funding to run a small Heritage BIM project. I’m running a photogrammetry project on a few small and less well-known industrial remains in the Swansea Valley. The proposal is to explore how effective and economical cheap photogrammetry can be in surveying and analysing small structures and supplement statements of significance. With reference to CIDOC and ISO 19650.

I worked on several Heritage BIM projects whilst an analyst on the Restoration and Repair of the Palace of Westminster. The technologies are evolving fast, and the extortionate costs of older photogrammetry are now being superseded by new technologies and approaches. I remember the original photogrammetry of the Palace was eye-wateringly costly, but once captured, hardly anyone knew how to effectively leverage the data into applied and valuable information. The result was old data that quickly went out of date and used before it could benefit the programme.

This will be an opportunity to explore revised workflows, effective use of low-cost technology, and output into usable heritage information for a few neglected monuments. It also provides an opportunity to revise old and outdated information, review the significance of the monuments in light of more recent viewpoints on heritage and interpretation, and maybe look at ontology and some standardisation and interoperability issues in HBIM. All with a view to convert data into valuable knowledge effectively and for a reasonable cost.

I’m looking forward to getting back into HBIM and a heritage project!

Above: A prime candidate: a significant structure from eighteenth-century coal mining history. It is mainly unprotected and needs modern interpretation.

Now working on the final shortlist of appropriate monuments and structures for the project. Down to a shortlist of three. The final selection will depend on the extent of the current knowledge and interpretation of the selected structure. A poorly documented structure will score higher.

If you want to know more, take a look at this Heritage building information modeling (HBIM) for heritage conservation: Framework of challenges, gaps, and existing limitations of HBIM and Photogrammetric Applications for Cultural Heritage.

My next illustrated talk

This will be at the Local Studies Room at Swansea Central Library on Saturday, 22 February 2025 at 2.00 pm. This will be one of Gwilym’s local studies talks in the afternoons. (https://www.swansea.gov.uk/centrallibraryevents).

Above: The Lower Swansea Valley as seen by German bomber cre3ws in February 1941

I’ll talk about the three nights of air attack that transformed the town centre. Based on my research for my Y Tân: A History of Destruction, Swansea 1941.

In World War Two, Swansea was regularly attacked by the German Air Force. The worst attacks were over three nights in February 1941. The bombs and fires transformed the centre of the town, and the author’s grandfather was killed as a volunteer firefighter. This book explores the events of the three nights, the loss of the author’s grandfather, how the fire was used to destroy the town and the consequences of the raids for the future of Swansea. Swansea Blitz was an early example of a firestorm and became a template for attacks on many European towns and cities in 1942 and 1943. The author reconstructs the events of the three nights and includes eyewitness descriptions from some of the people who worked to save lives and property. The book also includes an analysis of the loss of the Ben Evans department store and the detailed history of the land we call Castle Gardens. With technical details of the bombs and explosives that were used to attack the town and the history of the bomb disposal teams that worked to save Swansea. Based on meticulous research this fully referenced book examines the vulnerability of the town to air attacks, the technical background of the incendiary bombs, the events of the three nights of terror, the ecology of the devastated town centre and the aftermath of rebuilding.

I’ll have both Y Tân and Eye of the Eagle books for sale at a discount price of £10.00 each. The new editions won’t be available on Amazon or local bookshops.

History of the Luftwaffe Reconnaissance and Intelligence during the air war over South-Wales 1939-1941. Over 130 maps, illustrations, and images, many in colour. Individual biographies of the Luftwaffe intelligence of Newport, Cardiff, Penarth, Barry, Port Talbot, Llandarcy Oil Refinery, Briton Ferry, and Swansea. Explanatory text and translation of original Luftwaffe intelligence records. Annex describing intelligence records, U-boat operations off Swansea and Magnetic Mines. Explanatory text covering the role of intelligence and reconnaissance and explanations of why the Welsh ports were bombed in the Blitz attacks of 1941. Illustrated with Luftwaffe intelligence maps and documents gathered from over 10 years of research. Fully academically referenced.

Kilvey: Recent storms and Windthrow

Kilvey Hill experiences frequent storms and high winds, which are a major threat to woodlands and any buildings or structures. The risk of wind damage and windthrow is expected to increase with climate change, with more frequent storms, wind speed, winter rainfall, and faster tree growth.

The projected increase in our winter rainfall is likely to increase wind risk, as rooting depth and root anchorage are both reduced in waterlogged soils. An increase in tree growth rate due to warmer temperatures is possible in areas where moisture availability is not limiting, this could increase wind risk with stands reaching a critical height earlier.

The presence of the TV and phone masts on the hill means that we know a lot about the wind speeds and weather on the hill. However, getting hold of the data is sometimes hard as it can be regarded as a ‘secret’. Anybody who walks the hill will know the signs of wind damage and constant high winds, which are now increasingly common around the year, no longer just the winter months.

We can use the table below to assess wind speeds and damage based on the evidence we see after the storm is over. This table is based on expert fieldwork from the US Forest Service and is used all over the world. Look at the damage in the photos here and see where it is on this list…

It doesn’t matter what your viewpoints are on who or what causes climate change. The evidence is out there, and the question is how to interpret it and design for the future. It might, for instance, be an incredibly risky act for Swansea Council to risk millions of pounds (of money they apparently don’t have) on supporting a risky tourism venture on a Welsh coastal hill that is increasingly exposed to dangerous windspeeds and disruptive weather.

Those who walk the hill regularly know of the health and safety responsibility of taking walkers out on Kilvey in deteriorating or unsettled weather. We never take the risk. Would a profit-centred tourist firm be equally responsible? Would you get in cable cars and zip wires in the bad weather? Equally, how many days a year is Kilvey safe for adventure tourism? I’m not sure, but I can be confident that climate change means that the number of days of safe weather is declining as the climate changes.

Storm damage above White Rock works in January 2025.
Above wind and wildfire damage in the ‘Skyline Zone’ 2023.