Tenn. Code Ann. § 41-4-118

In all cases where a defendant charged with the commission of a felony is committed to jail, either before or after trial, and the safety of the defendant or the defendant's safekeeping, requires a guard, it is the duty of the sheriff to employ a sufficient guard to protect the defendant from violence and to prevent the defendant's escape or rescue. Nothing in §§ 41-4-118 — 41-4-120 authorizes the employment of a guard in cases of insufficient jails, but in such cases the defendants shall be sent to adjoining counties, as required by law.