ENERGY STUDY OF UNDERGROUND RAPID TRANSIT.

Underground rapid transit systems can generate enough heat from their operations to raise tunnel and station temperatures as much as 15 or 20 degrees Fahrenheit above outdoor temperatures, the greatest differences being at night and in the early morning hours. At the time this study was undertaken no detailed development of the energy transfer occurring in underground transportation systems had been made available in the open literature. The author develops a preliminary analytical model for evaluating these energy transfers. The usefulness of such a development would be in its identification of major energy transfer problems and critical parameters for further engineering study. Of particular significance in the study are its implications in the design of air conditioning for the transit cars and stations. It is likely that the most severe design conditions for air conditioning of rapid transit cars will be during underground operation. The complete air conditioning of stations is apt to be prohibitively expensive unless the station design permits routing away certain high energy sources.