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.

  • ameancow@lemmy.world
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    5 days ago

    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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      5 days ago

      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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        5 days ago

        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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          5 days ago

          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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            4 days ago

            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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          5 days ago

          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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              5 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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      5 days ago

      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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        5 days ago

        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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          5 days ago

          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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            5 days 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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              5 days 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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                4 days 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.

                • Dasus@lemmy.world
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                  4 days ago

                  Instead of sourcing your shit and/or answering my last question, you just can’t do anything else than take it personally.

                  I wasn’t being a dick. Asking for a source isn’t being a dick.

                  Just because you imagine me having a complaining or whining voice doesn’t make it so. You’re projecting shit from your consciousness onto me.

                  If an assertion is made without any proof, it is equally easy to dismiss it. This is literally rhetoric 101. But yes, I know you äidin lil’ kullanmurut get so upset when someone dares to question a thing.

                  And thats why you’ll stay an introverted socially inept weakling.

                  “Perättömistä syytöksistä”

                  Name one. Oh you can’t? What did I accuse you of. You’re the one being insanely dickish here, because you can’t read neutral comments as neutral. Literally the reason Finland sucks is the attitude you’re exemplifying, and also a threat to our democracy. But you would never believe it no matter what, so it’s no use talking about it.

                  Oh and another “I’m gonna block you”. People who say that never do, because you’re so utterly desperate to see what I think about your message.

      • ameancow@lemmy.world
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        5 days ago

        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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          5 days ago

          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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            5 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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              5 days ago

              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?