Wubei Zhi (Vol. 48)

This page contains two technical illustrations of defensive military equipment. The top illustration shows a "Cha Ban" (Insertable Board/Gate). It depicts a rectangular wooden structure composed of horizontal slats, suspended by thick ropes or chains on both sides. The ropes pass through metal rings, suggesting a mechanism for raising and lowering the board, likely used to block gates or breaches in a fortification. The bottom illustration shows a square or rectangular plate or shield covered in a grid of small circular studs or holes, possibly a reinforced metal plate or a component of a defensive trap.