Convert from ridge to arsheen [Russia]

Unit Definition (ridge)
The ridge is a traditional Welsh unit of distance equal to 3 leaps or 20 feet 3 inches (6.1722 meters).

Unit Definition (arsheen [Russia])
The Arsheen, also called the Archin, Archine, Archinne, Arschine and Arshin. In the early 18th century, the Tsar Peter the Great issued a ukase redefining the traditional Russian units of length in terms of the English foot. The archin was made equal to 28 English inches, 71.12 centimeters or 16 Vershki.