Convert from qintar [Arab] to keel [coal]

Unit Definition (qintar [Arab])
The qintar is a traditional Arabic unit of weight, often called the cantar in English. The qintar is the Arabic counterpart of the European quintal. The unit varied in size from market to market and over time. In recent years, the qintar has been interpreted as an informal metric unit equal to 50 kilograms (110.23 pounds); traditional qintars tended to be a few percent larger than this. The qintar is equal to 100 rotls.

Unit Definition (keel [coal])
The keel is a traditional British unit of weight for coal. After considerable variation, the keel of coal was standardized in 1695 as 21.2 long tons, or 47 488 pounds (21.5402 metric tons). This is the approximate weight of coal carried at that time by barges on the river Tyne in northern England; the barges were also called keels, from the Dutch word kiel for such a ship.