Most bridges here do, and often when one needs to be demolished and rebuilt, the military blows it up just for practice.

Edit: Source for the sceptics

The deep demolition, which became a central element in Finnish post-war demolition tactics, and especially the development of readiness to counter surprise attacks that emerged as a threat scenario in the 1960s, received significant support immediately after the wars. The decision concerning structural demolition preparations for bridges was made on January 15, 1946. These preparations meant building charge wells, charge chambers, charge pipes, and charge hooks. Authorities responsible for constructing bridges were required to include the aforementioned structures in their plans, which significantly improved the readiness to destroy the bridges.

If it was not possible to place the charge space inside the abutment or pier, charge hooks could be embedded in the supports during the casting phase, to which the charges could then be attached.

  • Iconoclast@feddit.ukOP
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    2 days ago

    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.

    • Dasus@lemmy.world
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      2 days ago

      Yeah but I don’t see those hooks as being related. You don’t really need hooks like that to blow a bridge and that’s a small underpass of a regular road. You could cave that with a few sticks of TNT. And drilling them into the wall is much more efficient than hanging them off the wall.

      I just suspect these hooks are just remnants of building it, and not for any specific purpose. Don’t really care if I’m wrong but I won’t be dissuaded unless someone actually proves it properly.

      • Iconoclast@feddit.ukOP
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        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.

        • Dasus@lemmy.world
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          Yeah I’ve seen them as I’ve driven Turku-Hki highway 1 and the old nr 1 as well.

          For me it’d be much more believable if we we’re talking about eastern cities. The road infra around the eastern border, no matter how clearly designed against an invasion from the East, was not talked about for decades. But they’ve since loosened the policy.

          I understand the logic. I just don’t buy into it. I understand I can be wrong but eh, until further evidence is presented this is my opinion.

          Drilling is slow, yes, but explosives not in a structure just hanging on a hook outside are very much not efficient at destroying the structure. So if that’s the case, you’d pre-drill holes for explosives. Which they apparently do do in the East.

          I do find confirmation of plans to destroy the bridges, but the words used are “charge pits” or panostustila/panostusaukko in Finnish.

          I just can’t believe it’d be silly hooks like that so close. That to me seems just like the steel that’s strengthening the concrete.

          • guy@piefed.social
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            2 days ago

            It’s the military. I think they have enough kaboom to raze a bridge even without drilling

            • Dasus@lemmy.world
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              It’s the military. I was there, and remember everything usually being done as efficiently as possible. What would you get by hanging explosives on the walls? A big boom which isn’t even guaranteed to take down the bridge unless you use an excessive amount, whereas with the so called “charge pits”, you only need a few sticks of dynamite or an equivalent amount of a modern explosive.

              Why do they call them “charge pits” if they’re actually just nails you hang explosives from? And why go through the trouble of hanging them ouf of something when they’re gonna be practically identically efficient from the ground?

              Idk man, I just don’t accept these mutu-based posts. (That’s “mutu” as in “musta tuntuu” as in “well I feel like this is so”.)

              It might be they are for them, but I’m not going to believe it, because they don’t seem to be “pits” of any sort.

              • guy@piefed.social
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                5 hours ago

                Oh I can’t say I know if the hooks are for demolition. But I mean the military should have the explosives and know-how to raze a bridge even without drilled holes, like with shaped charges.

                • Dasus@lemmy.world
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                  3 hours ago

                  Yeah sure, they do, ofc. Hell, the military has literally vehicles that become bridges in case someone else has blown up a bridge.

                  My point is that I often found in the military that things are ultimately done because they make sense. (And I don’t want a bunch of people here complaining about making their beds, discipline, cleanliness and uniformity does have a purpose.)

                  I just think these hooks seem be really close to each other and I only found articles talking about charge “pits”, but someone did link a Finnish thing where they said “panoskoukku” so could very well be and I’m not arguing against it anymore.

      • ameancow@lemmy.world
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        And drilling them into the wall is much more efficient than hanging them off the wall.

        You cannot do this for a tactical retreat, which these kinds of slowing tactics require, they need to divert armored columns within minutes of the advances. I don’t have a source on if that’s what the hooks are specifically for, but I can think of nothing else that would aid a rapid demo more, that wouldn’t also be prone to problems.

        Two soldiers with charges they taped or roped together ahead of time can throw them in line across the hooks in under a minute and get out. Large, overkill charges and in a relatively enclosed space wouldn’t deflect into the sky like laying them on the surface. KISS.

        • Akasazh@lemmy.world
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          they taped or roped together

          Why not tape them to the bridge too?

          I feel like driving out to the bridge would take longer than drilling a hole (with the benefit of maximizing destructive power).

          • ameancow@lemmy.world
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            Why not tape them to the bridge too?

            Go get a baby. I guess something else that weighs similar would also work, but the awkwardness of a baby conveys the right level of fuss you would take with individual charges, and grab a roll of duct tape, then find a concrete wall of some kind and see how much tape you need to stick that baby to a rough old dirty concrete wall.

            (Do not detonate the baby.)

            • Akasazh@lemmy.world
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              However, of you drill, you don’t need the volume of a baby, just a few of sticks of c4.

              Just take a look at how buildings are demolished, they drill holes. It’s the best way to destroy a building. Why would the Finns be silly and not do that. If it’s so important one could pre drill those holes, limiting time.

              • Iconoclast@feddit.ukOP
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                Why would the Finns be silly and not do that.

                If it was not possible to place the charge space inside the abutment or pier, charge hooks could be embedded in the supports during the casting phase, to which the charges could then be attached.

                Source

            • Dasus@lemmy.world
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              The point is that you could do that, with a roll of gorilla tape.

              The point isn’t it’s more awkward to do and takes longer, the point is that the explosive force delivered to the bridge would be the same. (Actually slightly more with a gorilla tape covered explosive as it would marginally increase the forces on the bridge compared to just hanging ones.)

              If you put an explosive inside the bridge, the force delivered to the structure is several times more. Thus it would make sense to have “pits” to out explosives into, not just hooks to hang them off of.

                • Dasus@lemmy.world
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                  2 days ago

                  Sure you did.

                  I know, it’s annoying when someone asks for something to make sense when you’ve already decided it’s true no matter if it does or doesn’t make sense.

                  “Charge PITS”, not “nails” or “hooks”.

        • Dasus@lemmy.world
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          but I can think of nothing else that would aid a rapid demo more, that wouldn’t also be prone to problems

          Literally drilled holes? I googled this a bit and they call them “charge pits”. I find it weird they’d call them “pits” if they’re just rebar they hang explosives off of.

          You don’t decide to blow a bridge willy-nilly, and they need to have explosives anyway, and since the bridges are blown in advance, I don’t think they’d be in the middle of a tactical retreat.

          Blowing up bridges with methods you decide during peacetime is strategy, not tactics.

          • Iconoclast@feddit.ukOP
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            I struggle to understand why you oppose this so much. You already confirmed that they indeed leave charge pits on bridges for the exact same reason. Why don’t you want to accept that these hooks serve the same purpose, but they’re used when a charge pit is inconvenient - like on the support pillars in the middle?

            I just got back from a 100 km trip, and I paid extra attention to this. These hooks were on every single bridge pillar I saw. There are charge pits at each end and hooks on the support pillars. It’s not rebar either, but prefabricated hooks that are clearly put there for a purpose.

            I’m really tempted to just email Destia and ask for a confirmation but I feel like asking stuff like that might sound a bit suspicious so I hesitate.

            • Dasus@lemmy.world
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              I’m not opposed in any way. I just don’t personally believe it. I think OP is full of bullshit, as a lot of people are.

              I couldn’t even recall the amount of “facts” people throw around and then get super mad when someone points out their “facts” don’t make sense at all.

              These hooks were on every single bridge pillar I saw

              Yep. All around Finland.

              All the talk of the defensive strategies (that we’ve had since the Winter War) only speak of these being applied to the eastern part of Finland. And you can even look at a map to see the roads round there mainly going in the same way and there not being lots of roads joining them. It’s all part of their defensive strategy. Shutting off infra from where an attack would come from.

              But what is the fucking point in supposedly being ready to blow up a bridge in Forssa? Tell me the strategic advantage any enemy would have with it?

              I’m really tempted to just email Destia and ask for a confirmation but I feel like asking stuff like that might sound a bit suspicious so I hesitate.

              Go ahead if it bothers you so but yeah unless they confirm it or you make even a remotely rational explanation to them, I’m not buying it. Why does me not personally believing in something bug you so? If you need No proof to assert it, I need No proof to assert the negative of the same assertion.

              • Iconoclast@feddit.ukOP
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                1 day ago

                Keskeisen aseman suomalaisessa sodanjälkeisessä suluttamistaktiikassa saanut syvä suluttaminen ja etenkin 1960-luvulla uhkakuviin nousseen yllätyshyökkäyksen torjuntavalmiuden kehittäminen saivat merkittävän tuen heti sotien jälkeen. Siltoja koskeva päätös rakenteellisista suluttamisvalmisteluista tehtiin 15.1.1946. Niillä tarkoitettiin panoskaivojen, panoskomeroiden, panosputkien ja panoskoukkujen rakentamista. Siltoja rakennuttavat viranomaiset velvoitettiin sisällyttämään suunnitelmiin edellä mainitut rakenteet, joiden ansiosta siltojen hävittämisvalmius parani oleellisesti.

                Mikäli panostilan sijoittaminen maa- tai välituen sisälle ei ollut mahdollista, tukiin voitiin valamisvaiheessa sijoittaa panoskoukkuja, joihin panokset voitiin kiinnittää.

                Lähde

                • Dasus@lemmy.world
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                  1 day ago

                  Noni.

                  Eihä se nii vaikiaa ollu löytää jotai lähdettä. Thänks

                  Is there any info on how the hooks are used, what kind of charges?

                  • Iconoclast@feddit.ukOP
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                    1 day ago

                    Kyllä kannatti taas käyttäytyä kuin mikäki mulkku. On turha varmaan jäädä odottelemaan minkäänlaista anteekspyyntöä tästä lapsellisesta käytöksestä ja perättömistä syytöksistä. Eikä kannata vaivautuakkaan - ei tule jatkossa viestit enää perille.

          • ameancow@lemmy.world
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            I don’t have the energy to try to take this hill from someone who has watched too many movies or Hearts of Iron IV to even take this realistically, you get to live this day.

            • Dasus@lemmy.world
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              I’m a supply core undersergeant, so I literally went through lists of military equipment when I was serving. Never saw anything related to using antitank mines for improvisational demolition charges.

              Just admit you don’t have any reason. You can’t rationalise it, but despite the overwhelming lack of evidence and logic, you still believe it. This is why Finland (or rather Finns) suck.

              Blowing bridges isn’t something you do when you’re doing a tactical retreat. Blowing up bridges is something you do strategically. Guess you can’t tell the difference, both synonyms to you?

              • ameancow@lemmy.world
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                2 days ago

                You are deeply, deeply repulsive to try to chat with, I hope you have friends in real life.

                • Dasus@lemmy.world
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                  Yeah I find it deeply annoying to talk to whiny people who get upset when you question something they’ve said. In fact I make it a practice not to be with such people, because they’re usually really emotionally unstable. Usually it’s the less intellectually robust people, and they get mad when you remind them of it.

                  See what you’ve just told me is you’re repulsed by even the suggestion of “try to rationalise this thought you have”.

                  Eww.

                  “Charge PITS.”

                  But I’m sure that’s just a translation error, right?