Convert from shekel [Hebrew] to keel [coal]

Unit Definition (shekel [Hebrew])
The shekel is an ancient Hebrew unit of weight (and also a coin having that weight). The shekel was the Hebrew version of a Babylonian unit used throughout the Middle East. Accounts differ on its size. A frequently quoted equivalent is 252 grains, which is equal to 0.5760 ounce (avoirdupois) or about 16.33 grams, but other sources quote a value of 8.4 grams or various values between these two extremes.

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.