Comments by "TheEvertw" (@TheEvertw) on "Was Fort George In Scotland Impregnable?" video.

@2adamast "that design doesn't work against mortars" Yes it does. That is what those "bomb-proof shelters" are for. A mortar doesn't penetrate several meters of topsoil. Those administrative buildings have no defensive value, they are only for convenience. "polygonal forts -- are cheaper" Polygonal forts require additional forts within a kilometer or two to give fire support. That makes them anything but cheaper. Polygonal forts could be overrun due to the limited depth of defense, and the other forts were required to shoot any attackers that got on top of it, off. The lack of this support is what doomed Eben-Emael, for example. It was done right in the Nieuwe Hollandse Waterlinie and the Fortress Amsterdam, where dozens of forts are placed at regular intervals of 1 to 2 kilometers -- at astonishing expense. But neither has ever been taken by an enemy, and they prevented the invasion of the Netherlands in WW1 because the Germans knew they could not overcome them.
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In the 18th century, I would use deceit to capture this fort. A siege would have been problematic, with its open access to the sea and the British navy being the greatest in the world at the time... Bypassing the fort would also be problematic, as it allowed the Brits a staging area for counter-offensives. One way would be to make the lives of the Brits there so miserable they would abandon the place, by e.g. adding slow-acting poison to the water supply and the foodstuffs that came in, introducing sickness & disease, things like that.
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@2adamast True, the lack of covered close-defence kazemats is a severe weakness of this fort. The Dutch lines did have one additional feature: the land in front of the fortresses could be flooded, making the approach of (heavy) artillery very difficult. However by 1940 they had become obsolete. They were placed to protect the main cities, but by 1940 these cities were no longer out of range of an attacker. Especially if that attacker had bombers... Ever since WW2, fortifications have become futile, as any attacker is able to quickly concentrate so much force on a specific location that no fortification can withstand it. Defence-in-depth, mobile reserves and counter-offensives are how armies defend themselves nowadays.
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