In 1908, further dumping of refuse on the lake front was prohibited, and the Tunnel Company responded by building a new disposal station on the Chicago River. Here, elevators lifted tunnel cars to the surface where they were dumped into self-propelled catamaran "dump scows" with a capacity of . The scows then took the debris out into the lake for dumping in deep water.Frank C. Perkins, The Chicago Underground Railway System of Refuse Disposal, Municipal Engineering, Volume XXXV, No. 1 (July 1908); p. 21. George W. Jackson, the Tunnel's chief engineer, filed a patent on a scow fitting this description.George W. Jackson, Scow for Transporting Gravel, U.S. Patent 1,047,233, Dec. 17, 1912.
