Tennessee Code Title 65. Public Utilities and Carriers § 65-6-111

(a) In case any railroad company has acquired or owns a right-of-way over which its road is not already built, through or along any narrow pass, cliff, or gorge, where it may be unreasonably expensive or impracticable to put down more than one (1) track or line of railroad, any other railroad company, in good faith, desiring to build its line of road through or along the same narrow pass, cliff, or gorge, shall have the right to condemn a joint use of the right-of-way through or along the same, and, if after any railroad to be constructed through or along the same shall already have been constructed, any other railroad so desiring to build through or along such narrow pass, gorge, or cliff shall have the right to condemn a joint use of so much of the track as may be necessary, in like manner as railroads have the right to cross each other.

(b) Reasonable compensation shall be paid to the railroad company owning such right-of-way, or to the one whose right-of-way, or right-of-way and track, may be so condemned for such joint use with the other road, for its property and improvements and injury to its business, if any, which compensation, together with such reasonable restrictions as the jury of inquiry may prescribe at the expense of the second road for safely using such joint track, shall be fixed by the jury as in other cases of assessment of damages in the condemnation of private property.