URBAN GRAVITY-VACUUM TRANSIT SYSTEM: MARK 4B AND MARK 3B BASELINE DEFINITIONS

The mark 4b urban gvt is best suited to large cities. The smaller system, mark 3b urban gvt, is better suited to the small city that does not require the larger capacity of the mark 4b. The smaller size of the mark 3b configuration also affords significant savings in capital and operating costs. Conventional trains traveling at 200 mph require approximately 10,000 horsepower simply to overcome aerodynamic drag; at higher speeds, the drag increases in proportion to the square of the velocity. To avoid prohibitive power requirements at such speeds, a vehicle must avoid traveling through air at sea level density, nonetheless, the vehicle must be surrounding by normal air pressure when passengers enter and leave. To satisfy these two conditions, gvt trains will travel through evacuated tubes but will emerge from the tubes at each station. As a mark 4b train enters or leaves the tube, its 10,750 square-inch cross section generates an axial pneumatic force of 77 tons,--a force which, utilized to assist gravity acceleration/deceleration by means of pneumatics, can be perceived by the passengers; to maintain comfortable levels for acceleration and deceleration, each mark 4b gvt train will weight no less than 350 tons. The same pumps and valves that evacuate the tubes can furnish propulsive power to the entire system by means of selective control of the 77-ton thrust. Each pump, mounted close to the station, can enjoy the luxury of a fixed location, a conservate design, and unrestrained access for maintenance; the train, in turn, avoids the weight, bulk, safety hazards, and maintenance problems associated with an on-board power plant. A cost estimate is presented for a system consisting of three lines that would traverse Manhattan Island; each line would provide peak passenger capacity of 50,000 per hour per direction for Manhattan's central business district. The total estimated cost of the 92.9-mile, 74-station system is $2.055 billion (about $22 million per mile).

• Corporate Authors:

  Tube Transit Corporation

  P.O. Box 11335
  Palo Alto, CA  United States  94306
• Publication Date: 1970-5

Subject/Index Terms

• TRT Terms: Intelligent transportation systems; Tubing
• Old TRIS Terms: Advanced systems; Tube systems
• Subject Areas: Operations and Traffic Management; Railroads;

Filing Info

• Accession Number: 00044198
• Record Type: Publication
• Source Agency: Urban Mass Transportation Administration
• Files: TRIS, USDOT
• Created Date: Jun 15 1974 12:00AM