Of the 'movable shelters' we get a fairly clear description from several commentators. The name is also applied to turrets on city walls.

Tu Mu says they were wheeled vehicles used in repelling attacks, but this is denied by Ch`en Hao.

This seems to suggest a sort of Roman TESTUDO, ready made. Ts`ao Kung simply defines them as 'large shields,' but we get a better idea of them from Li Ch`uan, who says they were to protect the heads of those who were assaulting the city walls at close quarters. It is not quite clear what the Chinese word, here translated as 'mantlets', described.

The preparation of mantlets, movable shelters, and various implements of war, will take up three whole months #