There is a technique known as dry stone walling, in which stone walls are built without using mortar or concrete, but only by the weight of the stones and their interlocking. This is a traditional technique used for stone walls in castles, but it is also used in terraced rice paddies in mountainous areas, where people pile stones from the local area by themselves. Despite the easiness of their construction, if the stones are stacked properly, they are extremely long-lasting. Even if they collapse due to earthquakes or heavy rains, they can be quickly repaired by local people themselves. It was a familiar technique in people's lives at that time.
However, these days fewer people have experienced dry stone walling.
Old, crumbling stone walls have been abandoned or replaced with concrete walls, and the tradition is dying out.
On the other hand, the construction method of dry stone walling is environmentally friendly and sustainable, as it can be built and repaired again and again using only human power and existing local stones. The value is being re-evaluated recently.
We designed “Stonewall Bench”, a bench for the education and promotion of the dry stone walling technique in collaboration with Dry stone walling school of Japan, an association that aims to pass on the art of dry stone walling, and Ashidachi Lime Co.,Ltd. in Okayama Prefecture, which sympathises with the school's activities.
When piling tall stonewalls, iron rods called “shousen” are inserted into the gaps between the stones, and a board is passed over them to provide a temporary scaffold for piling stones even higher.
Referring to this method, the bench was designed to seem to be floating by inserting support rods into the gaps between the stones.
This method is only possible because the stone wall is not filled with mortar.
Since the gaps between the stones are not at regular intervals, a perforated metal is provided on the underside of the bench to accommodate misalignments, and the bench is fixed to the stone wall by inserting rods through these holes.
The rods are supported solely by the weight of the piled stones, and by sitting on this bench, people can actually experience the weight, strength, and solidity of the stone wall.
Until now, the opportunity of experiencing dry stone walling has been limited to the workshops for repairing stone walls in regions far from urban areas. The Stonewall Bench is intended to create a new potential of stone walls in cities as street furniture and, consequently, to popularize dry stone wall technique.