Wheelbarrow.

 This is coolbert:

"Not only is it useful for transporting army rations, but at need it can be employed as a defensive obstruction against cavalry. Since the digging of trenches and moats, and the building of forts, take time, the wheelbarrows can be deployed round the perimeter so that the enemy's horses cannot easily pass over. This kind of vehicle can readily go forward and withdraw, and can be used for any purpose. It might well be called a 'mobile fort'." - - 1176, Tsêng Min-Hsing.

Courtesy Bayou Renaissance Man. Large portions extracted in entirety and shamelessly so To war with wheelbarrow.

"Thoughts on wheelbarrows"

LEAVE IT TO THE CHINESE!

"The Chinese wheelbarrow - which was driven by human labour, beasts of burden and wind power - was of a different design than its European counterpart. By placing a large wheel in the middle of the vehicle instead of a smaller wheel in front, one could easily carry three to six times as much weight than if using a European wheelbarrow."

"The one-wheeled vehicle appeared around the time the extensive Ancient Chinese road infrastructure began to disintegrate. Instead of holding on to carts, wagons and wide paved roads, the Chinese turned their focus to a much more easily maintainable network of narrow paths designed for wheelbarrows. The Europeans, faced with similar problems at the time, did not adapt and subsequently lost the option of smooth land transportation for almost one thousand years."

"As so many other innovative technologies, the Chinese wheelbarrow was originally developed for military purposes. The first records mention its use for supplying food to the army. The wheelbarrow gave the Chinese armies such an advantage in moving goods that it was kept secret - early Chinese writings talk about wheelbarrows in code. True to its origin, the wheelbarrow remained in use for military operations, though not only to supply food to soldiers."

IN ADDITION CAN FUNCTION AS A MOBILE FORT? EVEN CONSIDERED A STATE SECRET.

Impressive.

coolbert.