Wash. Rev. Code § 8.20.140
Any railroad company whose right-of-way passes through any canyon, pass or defile shall not prevent any other railroad company from the use and occupancy of said canyon, pass or defile for the purpose of its road in common with the road first located or the crossing of other railroads at grade, and any railroad company authorized by law to appropriate land, real estate, premises or other property for right-of-way or any other corporate purpose may present a petition, in the manner and form hereinbefore provided, for the appropriation of a right-of-way through any canyon, pass or defile for the purpose of its road where right-of-way has already been located, condemned or occupied by some other railroad company through such canyon, pass or defile for the purpose of its road, and thereupon, like proceedings shall be had upon such petition as herein provided in other cases; and at the time of rendering judgment for damages, whether upon default or trial, the court or judge thereof shall enter a judgment or decree authorizing said railroad company to occupy and use said right-of-way, roadbed and track, if necessary, in common with the railroad company or companies already occupying or owning the same, and defining the terms and conditions upon which the same shall be so occupied and used in common.
RCW 8.20.140