Q. I am now at Fort Dix. I need to show ID for food. Can I carry on Shabbos? There is a tall fence all around the property. Is that considered an eiruv for Shabbos purposes?

Sincerely,

A. There is no concern that inner fenced areas may be a Karfaf, since the area is used for habitation purposes. (A Karfaf is an area surrounded by an enclosure, but not roofed over like a large courtyard. A Karfaf is approximately 5000 sq. amos or from 12,800 to 20,000 sq. feet, depending on the various opinions on the size of an amoh. It is in any shape, and is not intended for habitation. Our Sages banned carrying an object within).

There is also no worry that gates more than ten amos wide will be left open, as this is unlikely to occur in prison.

Therefore there is no problem carrying in the premises on Shabbos.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a