Taikokabe

What a taikokabe is

A taikokabe is a wall built with two skins and packed between them to stop bullets. The Japanese name compares the two faces to the heads of a drum.

The south corner turret of the third bailey at Ozu Castle in Ehime Prefecture is an Important Cultural Property, and the city of Ozu records that its interior has a bulletproof wall of this kind with bamboo tubes and other material set inside it, together with three Sama covered over with Shikkui so that nothing shows from outside.

The description indicates that the cavity between the skins was packed with bamboo tubes, presumably to absorb and slow a shot.

The same page records three flared Ishiotoshi on the outer walls of the turret, so that all three devices are combined in one building.

How the records treat it

The term does not appear in the architectural records of the National Cultural Properties Database. The structure field of those records states the roof form, the covering and the size; it does not describe what is inside a wall.

Researching the term therefore means going to municipal cultural property pages or survey reports. The Ozu page cites this wall and the concealed openings among the grounds for designation, treating them as central to the building's value as military architecture.

Nothing shows from outside. The wall is no thicker than any other, and unless the interior is open to visitors there is no way to confirm it on site, so any description should say which source it rests on.