Illinois Railroad & Warehouse Commission (lists of installations)

Illinois RR&WC. Statement of interlocking devices. 1890   553.5 KB
Illinois RR&WC. Statement of interlocking devices. 1892   196.5 KB
Illinois RR&WC. Statement of interlocking devices. 1893   873.3 KB
Illinois RR&WC. Statement of interlocking devices. 1894   250.3 KB
Illinois RR&WC. Statement of interlocking devices. 1895   910.1 KB
Illinois RR&WC. Statement of interlocking devices. 1896   1.4 MB
Illinois RR&WC. Statement of interlocking devices. 1897   972.5 KB
Illinois RR&WC. Statement of interlocking devices. 1898   954.7 KB
Illinois RR&WC. Statement of interlocking devices. 1899   1.4 MB
Illinois RR&WC. Statement of interlocking devices. 1900   2.1 MB
Illinois RR&WC. Statement of interlocking devices. 1901   2.3 MB
Illinois RR&WC. Statement of interlocking devices. 1902   3.0 MB
Illinois RR&WC. Statement of interlocking devices. 1903   2.8 MB
Illinois RR&WC. Statement of interlocking devices. 1904   3.4 MB
Illinois RR&WC. Statement of interlocking devices. 1905   3.6 MB
Illinois RR&WC. Statement of interlocking devices. 1906   3.0 MB
Illinois RR&WC. Statement of interlocking devices. 1907   4.7 MB
Illinois RR&WC. Statement of interlocking devices. 1908   3.6 MB
Illinois RR&WC. Statement of interlocking devices. 1909   3.1 MB
Illinois RR&WC. Statement of interlocking devices. 1910   3.9 MB
Illinois RR&WC. Statement of interlocking devices. 1911   4.2 MB
Illinois RR&WC. Statement of interlocking devices. 1912   3.7 MB
Illinois RR&WC. Statement of interlocking devices. 1913   4.1 MB

Indiana Public Service Commission (lists of installations)

Public Service Commission of Indiana. List of interlockers in state. 1915   425.0 KB

Indiana Railroad Commission (lists of installations)

Railroad Commission of Indiana. List of interlockers in state. 1908   409.9 KB

Indiana Railroad Commission (various)

Railroad Commission of Indiana. Rules concerning interlocking devices. 1906   1.3 MB