This industry comprises establishments primarily engaged in providing specialized services for railroad transportation including servicing, routine repairing (except factory conversion, overhaul or rebuilding of rolling stock), and maintaining rail cars; loading and unloading rail cars; and operating independent terminals. Cross-References. Establishments primarily engaged in-- ? Providing railroad car rental--are classified in U.S. Industry 532411, Commercial Air, Rail, and Water Transportation Equipment Rental and Leasing; ? Factory conversion, overhaul, or rebuilding of railroad rolling stock--are classified in Industry 336510, Railroad Rolling Stock Manufacturing; and ? Providing rail car janitorial services--are classified in Industry 561720, Janitorial Services.