Page:New York subway ventilation.djvu/20

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Alternatives Analyzed

Referring to Diagram F it is evident that this is in its main features only an elaboration of the first suggestion of Chief Engineer Rice with the actual complications of those suggestions, as they were carried out on the old subway early in 1906 save and except that it was proposed to incorporate into the subway design and construction a central division wall suggested by Bion J. Arnold in his report of 1908. Detailed analysis has already been made of the results which would or would not follow from the construction of such a divisional wall, and we have seen that no material benefit could result. It now develops that this divisional wall separating, as it does, the uptown tracks from the downtown tracks is actually designed and contracted for to be built with a multiplicity of openings provided for therein so as to give employees ready access from one side of the subway to the other not only in the conduct of their regular work, but also in the event of emergency for themselves and passengers, and in addition to permit escape from oncoming trains. These openings are of such size and frequency, viz 2 feet wide by 7 feet high at 10 feet centers, that the divisional wall is little less than a huge grating! What possible service it could perform in even the contemplated scheme of ventilating the subway by the "piston action" of the train is almost beyond comprehension!

It is possible to get some idea of the cost involved when one realizes that this divisional wall is built of concrete 10 in. thick and is some 13 ft. in height and requires forms to make the openings referred to.

In addition to this, the wall in question runs the entire length of the subway, but is omitted entirely at all stations for the length of the stations, doubly emphasizing its failure to perform its intended function. Even if this were a solid and continuous wall, it could not aid in any