

I’m not sure if this is something you’ll find an official source for as FDF isn’t known for openly sharing information regarding national defence.
However, you can find plenty of discussion about it online and for example on this video it’s mentioned around the 1:25 mark.











Drilling is slow. Efficiency isn’t the point here, speed is.
This isn’t exactly a regular road either but highway number four which leads straight to Helsinki.
You can see these same hooks on the support pillars of most bridges as well. Once you start paying attention to it you can’t really unsee it.