This industry comprises establishments primarily engaged in manufacturing construction machinery, surface mining machinery, and logging equipment. Manufacturing drilling and underground mining machinery and equipment--are classified in Industry 33313, Mining and Oil and Gas Field Machinery Manufacturing; Manufacturing industrial plant overhead traveling cranes, hoists, truck-type cranes and hoists, winches, aerial work platforms, and automotive wrecker hoists--are classified in Industry 33392, Material Handling Equipment Manufacturing; and Manufacturing rail layers, ballast distributors and other railroad track-laying equipment-- are classified in Industry 336510, Railroad Rolling Stock Manufacturing.