Energy Requirements for High Speed Ground Transport Systems

Abstract

The Department of Transportation is investigating a number of technical alternatives for future high speed ground transportation systems. In several of the nation's most heavily travelled corridors it has become clear that continued reliance on air transportation will result in saturation of corridor air facilities within the present decade. Additional airports can be tolerated only at such great distances from population centers that their usefulness for short haul corridor traffic is seriously impaired. Additionally, devoting scarce and expensive suburban land to such use is not cost effective relative to ground transportation. It is hard to believe, but a simple calculation shows that the 18 square kilometers of land occupied by New York's JFK airport alone equals the area traversed by a 30 meter wide right of way extending from Boston to Washington via New York and Philadelphia. To carry the peak hour traffic expected on this route by 1985 requires a capacity of 4000 seats/hour. This is equivalent to 10 Boeing 747 departures in one hour for corridor service alone! By comparison Japan's double‐track, high‐speed rail line can provide up to 34,000 seats per hour, and has in fact carried 553,000 passengers in a single day.In addition to conventional rail systems which can provide speeds up to perhaps 300 km/h, still higher speeds are possible with vehicles suspended and guided by non‐contacting methods designated “tracked levitated vehicle” (TLV) systems. These include tracked air cushion vehicles, and magnetically levitated vehicles employing either servo‐controlled electromagnets or superconducting magnets. The energy requirement for such high speed systems is very substantial and for this reason it is particularly important to see that they are as efficient as possible. Aerodynamic drag is the predominant source of power consumption.