Official

A bridge that makes you feel "functional beauty". In general, you may often love the whole shape, but let's take a look here at it up to a few tens of centimeters. You can see a different world.
Bridges built in the old era, such as reconstruction bridges over the Sumida River, use a lot of round-headed studs. "Rivette," right? In Wikipedia, it is described as "a part that consists of a torso without a head and thread, inserts it into a holed member and holds it with a special tool to form plastic deformation and joins the opposite end."

It's hard to work!
In order to connect the iron plate and the iron plate, pass a bright red heat rivet into the hole opened on the iron plate and hit the other side of the round head to shape it. There are heights and distances from the hot place to the place where the rivet passes, so you have to repeat the remote work of throwing a red rivet and catching it over and over again. If you fail, you will get a lot of burns. Due to the need for skilled skills and labor, it is now hardly used.
Thanks to the craftsmen who worked.
I know one person who works in Chuo-ku and claims to be "Rivet Mania". Why don't you love the bridge from a microscopic point of view?