Wubei Zhi (Vol. 48)

Di Se Ground resistance: Use Ni Xu Ding barbed iron spikes embedded in boards. The boards are three inches thick, with lengths and widths of approximately two to three feet.

Tie Ling Jiao Iron water-caltrops: Resembling Tie Ji Li iron caltrops, these are spread in water to pierce the feet of men and horses.

Lu Jiao Mu Deer-horn wood: Select sturdy timber and cut it into the shape of deer antlers. Bury these several feet long into the ground to a depth of over a foot to obstruct horses' feet.

Tie Ji Li Iron caltrops: These are placed on key paths the enemy will travel to prevent men and horses from charging. In ancient times, these were called Qu Da iron foot-spikes.

Yang Ti Upraised hooves: Four pieces of wood are joined in a square shape, seven inches in diameter, with barbed iron spikes installed horizontally across the center. These are also used to block paths for horses.

Shui Ji Li Water caltrops: Made from triangular heavy wood.