DECIDE BETWEEN ROTARY AND BOTTOM-DUMP COAL UNLOADING

There are two basic ways to unload coal from a rail car at the power plant: rotary dump or bottom dump. (A third option, side dump, generally is applicable only for specialized short-haul situations.) Where rotary dumping is used, cars are equipped with rotary couplers so they may be turned over without uncoupling or breaking an air line. The standard cross-dump hopper has poor characteristics for rapid unloading. To bottom-dump coal efficiently while in motion, unit trains require a mechanized self-clearing, quick-dumping car - one that unloads in a matter of seconds - controlled automatically or semiautomatically. This demands a large bottom opening - either large doors or many doors - and usually a pneumatic- or electropneumatic- actuated door-opening and -closing system. Quick-dump cars also are more expensive than standard gondolas or hoppers. A fundamental step in selecting a coal-unloading system is to determine the cost of bottom-dump facilities and compare it to the price of a fleet of solid-bottom gondolas plus a rotary car-dumper. In short-haul situations, the more-rapid unloading of quick-dump cars may reduce the cycle time enough to save an entire unit train. The saving in time gained by using quick-dump cars may represent a significant dollar saving to the delivering railroad in terms of train-crew costs. Total operating cost for a rotary-car dumping system is likely to be less than the additional car-maintenance cost associated with the doors and actuating mechanisms of quick-dump cars. Finally, a rotary-dumper installation has the advantage of being entirely enclosed. Thus, control of dust is simplified. This could be important in the case of unwashed coal.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00325929
• Corporate Authors:

  McGraw-Hill, Incorporated

  330 West 42nd Street
  New York, NY  United States  10036
• Publication Date: 1975-8

Media Info

• Pagination: p. 47
• Serial:
  • Power
  • Volume: 119
  • Issue Number: 8
  • ISSN: 0032-5929

Subject/Index Terms

• TRT Terms: Bulk cargo handling; Coal; Coal industry; Couplers; Design; Electric power generation; Freight cars; Freight traffic; Gondola cars; Hopper cars; Unit trains; Vehicle design
• Old TRIS Terms: Bulk handling; Freight car design
• Subject Areas: Design; Energy; Freight Transportation; Railroads;

Filing Info

• Accession Number: 00128857
• Record Type: Publication
• Source Agency: Engineering Index
• Files: TRIS
• Created Date: Feb 4 1976 12:00AM