Ques. What is the advantage of direct drive?
Ans. The great saving in floor space, which is plainly shown in [fig. 2,732], the portion A' representing the saving which results over the installations previously illustrated in figs. [2,720] and [2,731].
Ques. How could the floor space be further reduced?
Ans. By employing vertical instead of horizontal engines.
Ques. What should be done before drawing the plans for the station?
Ans. The types of the various machines and apparatus to be installed should, as nearly as possible, be selected in advance so that their approximate dimensions may serve as a guide in drawing up the plans of the building.
Fig. 2,732.—Plan of electrical station containing direct connected units. As shown, space is provided for an extra boiler and engine and generator set, as indicated by the dotted lines. Space also exists for a storage battery room if necessary, and the partition dividing this room from the engine and dynamo room is shown by a dotted line as in previous cases.
Owing to the great difference in these dimensions for the various types, and in fact for the same types as manufactured by different concerns, no definite rules regarding the necessary space required can here be given. In a general way, however, the author has endeavoured to indicate by the drawings the relative amounts of space that ordinarily would be considered sufficient.