Mo. Rev. Stat. § 389.850: Application of provisions of sections 389.810 to 389.870.

The provisions and requirements of sections 389.810 to 389.870 relating to power drive wheel brakes, train brakes, automatic couplers, grab irons and the standard height of drawbars, shall be held to apply to all trains, locomotives, tenders, cars and similar devices used on or by any railroad engaged in the transportation of persons and freight between points within the state of Missouri; provided, however, that the provisions of said sections shall not apply to street railroads nor to tram railroads employed in the transportation of logs.