Ice siege of star fortresses, part one
 
Star fortresses are a very interesting phenomenon. There are many of them, they are different, but they are united by a common concept. It is also surprising that fortresses, or at least traces of them, have been discovered on different continents, sometimes in very unexpected places.
Of some, only barely visible traces remain, while others are well preserved. From the point of view of official science, this form made it possible to withstand artillery shelling - the cannonballs did not hit the wall at a right angle, but ricocheted, and thus caused less destruction.
Some points in this interpretation are confusing. So, for example, for some reason in these buildings not the entire fortress wall is a broken line. There are areas where the cannonballs will hit the wall exactly at right angles. Why did they leave vulnerable places for siege artillery?
Further, it is obvious that the highest possible fortress wall will protect against assault better than low walls located in several tiers.
Without trying to explain this phenomenon in all its diversity, I want to dwell on only one well-preserved fortress. This is the Fort Star of Graça or Fort of Our Lady of Grace (Forte de Nossa Senhora da Graça), in Portugal.

 
Ramparts radiate from the fortress, seeming to be a continuation of some corner projections, not even connected to the solid wall.


What is the role of these shafts so that the cannonballs also bounce off them? Why worry about a cannonball that didn't make it? From the point of view of fortification, such a solution looks, to put it mildly, ridiculous: defensive ramparts oriented not across, but towards the enemy. Moreover, they are even and smoothly fading away. Is this to make it more convenient for the enemy? But it took a lot of effort to create these shafts! And for something else, the geometry of these shafts was carefully observed! This contradiction suggests that this structure had, at a minimum, not only a defensive purpose, but also performed some other important function. And perhaps it was not even precisely defensive in its original intent.
Agree, the layout of the fortress itself looks rather strange. The logic of this technical solution seems to elude us. Perhaps, in order to understand it, we should find something similar from structures whose purpose is well known to us.
Ice cutters are used to protect bridge supports during ice drift. Below is a photo of such a device at the Tikhvin Monastery in Russia. I ask you to look at it carefully and use your imagination.
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Don’t you think that a similar technical solution is used here as at Fort Graça, only with a simpler structure and on a smaller scale? What if this was done to protect against a creeping glacier?
It must be said that a slowly advancing glacier is a terrible disaster. Because it is a single monolith of millions of tons. When moving, glaciers even smooth out mountains, what can we say about artificial structures! The only way to resist the glacier is to make sure that the leading edge of the shield, when advancing, cracks and breaks away from the main body of ice, losing its rigid connection with it. And the design of Fort Graça would be ideal for such a purpose.
Of course, the question arises: how could a glacier form and grow on the territory of modern Portugal, since glaciation did not reach the Iberian Peninsula? To do this, you will have to delve a little into the peculiarities of the processes of glacier formation and take into account the climate characteristics during the Ice Age.
The first thing to note is that severe frosts are not necessary for the formation of a glacier. The key condition is a very large layer of snow. With a sufficiently large amount of precipitation, a temperature slightly below zero will be sufficient for its formation. Under the pressure of the overlying strata and a decrease in the porosity of the snow, recrystallization occurs, and the latter turns first into firn and then into ice. However, if the snow layer is sufficiently thick, the glacier can grow even at positive temperatures. Snow melts only in the upper layer, water penetrates into the lower layers, which store cold, and freezes. If negative temperatures prevail, precipitation falls mainly in the form of snow, and this snow does not have time to melt over the summer, then the formation of a glacier is quite possible. And if even with the heaviest snowfalls you can still manage to remove this snow, then a creeping glacier is a disaster for buildings.
During ice ages, cyclones moved towards the equator. At the same time, humidity increased in Southern Europe, Central Asia, Africa and North America. These are precisely the territories where the star fortresses were discovered. It was the large amount of precipitation with lower temperatures that ensured the growth of glaciers.
At the end of the Ice Age, it is quite logical to adapt the remaining of these structures into fortresses. Even with some of their fortification shortcomings, this is better than nothing.
From most star fortresses, only ramparts remain, sometimes barely visible. The buildings that existed on them were completely removed. For this reason, many researchers made a conspiracy-theological conclusion: someone maliciously and methodically destroyed these fortresses to the ground. Maybe there was no malicious intent: glaciers wiped them off the face of the Earth?
 

 

The next ice age, alas, is inevitable, and our descendants may still have to return to this technical solution.
Regarding the dating of star fortresses: I’ll add some food for thought. Below in the photo is the Petrovardin fortress on the Danube in Serbia. This is the largest fortress in Europe. It is said to have been founded by the Prince of Croix in 1692 to defend the Habsburg Empire from the Turks.
At its foot there are numerous corner projections, similar to the Graça fort, in several tiers, and all of them are below the fortress wall. Obviously, they are completely meaningless both as protection against artillery and from the point of view of fortification in general.
This is a view from above the fortress:
 



The diagram shows this multi-tiered system even more clearly:
 

 
And these are the corner projections from the Danube side, you will agree that for the defense of the fortress this is completely meaningless:
 


This entire system as a whole is an extremely well-built land “icebreaker”. This multi-tiered system of corner protrusions, with offset corners on each subsequent tier, made it possible not only to split the ice monolith vertically, but also to successively divide it into layers horizontally. But buildings of a defensive nature have different tasks and therefore a completely different logic of organization. From a military point of view, this scheme is not only useless, but also harmful: behind the edges of these corner ledges it is very convenient to hide from fire from the fortress during its assault, and this helps to consistently overcome one tier after another.
It would be more logical to build structures of this type not even during the current, but at the beginning of the ice age. Very long before the appearance of the prince who took credit for the construction of this stronghold.
Isn't it a recognizable form? These are traces of a structure in western Australia, 120 kilometers from the coast, coordinates:31°47'24.3"S 124°23'46.3"E.
 


In principle, it is normal that issues of defense of a fort or fortress are resolved on different continents in a similar way. The strange thing is that this place in the Goldfields-Esperance region is extremely inhospitable for living. The soils are extremely infertile and quite saline, there are no rivers, and any rain seeps in to form extremely saline groundwater. One sheep per square mile is the maximum sustainable rate. And such a sad picture has persisted for millions of years!
Historians explain to us that star-shaped fortresses were built to withstand siege artillery. We also know well that before the arrival of the white man, only savages lived in Australia. Who could try to defend against siege weapons in this God-forsaken place?!
Below in the photo is the Zavolzhsky historical shaft in Russia. Don't you find any structural similarities with the monastery icebreaker?
 


And this is the Serpentine Ramparts in Ukraine, the star fortress is integrated into their system:


And these are the Walls of Trojan. For what type of troops could this serve as an obstacle?! Well, maybe for the supply train. But their construction required enormous labor costs! If you continue to consider the ramparts a fortification, then this, alas, automatically means that you do not have a high opinion of the mental abilities of our ancestors!
 

 

I want to continue the conversation about defensive ramparts in the second part of the article.

eremeiyury wrote:

It is also surprising that fortresses, or at least traces of them, have been discovered on different continents, sometimes in very unexpected places.

That’s well observed and the amount of work which went into the construction of even one star fort must have been formidable. The engineering and upkeep costs would have been huge and all using just human and animal power. They are indeed found in many differing palces. There are even star forts to be found, for instance, in Taiwan (Formosa) where the Spanish in the north of the island and the Netherlands in the south briefly established trading posts in the mid-Sixteenth Century. The remains of the Dutch fort at Tayouan (today Anping) are still visible today.

Interestingly, and although star forts are to be found all around the world, there aren’t many examples of star fortifications to be found in the British Isles. In terms of maritime defences, the British tended to prefer the circular designs to be found in the device forts of the 16th Century and also the later Martello towers of the 19th Century. With regard to the former category of the device forts, then 2 of the finest examples are to be found in the Downes castles of east Kent. Deal Castle and Walmer Castle were built during the reign of King Henry VIII to guard the Downs anchorage off the coast. There was a third fort at Sandown but that is now a ruin. From the air they look more like flowers than stars.

eremeiyury wrote:

This entire system as a whole is an extremely well-built land “icebreaker”. This multi-tiered system of corner protrusions, with offset corners on each subsequent tier, made it possible not only to split the ice monolith vertically, but also to successively divide it into layers horizontally.

I can’t say that I’m convinced by the icebreaker hypothesis. That said - rather than stars they often look more like snowflakes and co-incidentally such bastion forts were indeed built during what is known as the Little Ice Age (c.1400-1800). The sloped earthworks which give a bastion its star shape are called glacis which is a French word meaning slippery derived from the word 'glace' meaning ice. But that's where the links with ice would seem to end however. Strategically the design of the glacis meant that siege engines and cannons could not approach the bastion walls at right angles but would be forced to point upwards thus reducing their effectiveness and also risk them sliding backwards out of position or even onto their operators.        

eremeiyury wrote:

From a military point of view, this scheme is not only useless, but also harmful: behind the edges of these corner ledges it is very convenient to hide from fire from the fortress during its assault, and this helps to consistently overcome one tier after another.

Surely the whole point of star fortifications was to lure the attackers into seemingly safe but in fact deadly, exposed spaces. To then try to overcome a succession of such tiers, would not only be physically exhausting for the attackers but also psychologically devastating.

I remember flying back (to Britain) from Rome a few years ago. It was an early spring day when virtually the whole of Western Europe was cloud free. A rare occurrence. To our right and against the blue sky were the snow-capped Alps which just looked spectacular. Even the pilot remarked upon them and set a rhetorical challenge to the passengers to see if they could identify the various iconic peaks – the Breithorn, the Dent Blanche, the Weisshorn, Monte Rosa, the Zinalrothorn, Mont Blanc and the Matterhorn etc. Unremarked, however, but directly below us on the Piedmont plain lay the city of Alessandria. Its gigantic 32-point cittadella was clearly visible standing out in the landscape. I had never heard of the Cittadella di Alessandria, before, so I looked it up upon returning home to learn that it had been built in the 1730s but hadn’t been very successful as a citadel having been taken by the Spanish in the 1740s and then by the Russians in the 1790s. That probably gives it a unique record among places in Europe having been laid siege to by both the Spanish and the Russians – i.e. by forces from each end of the continent. The fact that it fell twice is also proof that no matter how sophisticated the design of a fortification is, or how well provisioned the keep is, the outcome of siege inevitably depends upon the motivation and morale of the attackers and the defenders themselves.




(The flower-like design of Deal Castle in Kent, England. Built in 1540 its sunken foundation offered the inverse of the continental glacis feature. Siege engines and cannons would have to drop down into a confined and exposed moat to gain direct access to the castle walls.)

It is amazing that a huge number of similar fortresses are found on different continents. My compatriot created an interactive map of these structures. The inscriptions are in Russian, but this does not prevent its use. You can zoom in and view objects in detail.

https://www.google.com/maps/d/viewer?hl=ru&mid=1GZr_z7paiZuEtxnlLqBHBpUeZz0&ll=13.298157114407644%2C40.14022313285841&z=2