Tenons and tenoned beams in Japanese castle donjons

摘要

Tenoned beams hold an important position in the structural design history of Japanese traditional timber framed architecture. We have focused in particular upon horizontal beams with mortice and tenon joints in Japanese castle buildings. We have undertaken surveys of 6 donjons (tenshu) and one turret (yagura) that were constructed from the late 16th century to 17th century. Based upon the results of these investigations, this paper discusses the special characteristics of horizontal beams and their tenons in the framing of castle donjons in Japan.