Convert from bale [US] to keel [coal]

Unit Definition (bale [US])
The bale [US] is a commercial unit of weight for shipments of cotton. In the United States, one bale of cotton, formerly equal to 500 pounds (226.80 kg), is now equal to 480 pounds (217.72 kg). Other countries use a variety of cotton bale weights.

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.