from Jhffassrsy 



MA: :,.> 



The object of this article Is to present the 

 mathematical steps involved In preparing 

 the paper location of a railroad, a set of mathe- 

 matically consistent allnement notes by which to 

 run the corresponding fleld location; and to sug- 

 gest an orderly arrangement for the necessary 

 computations. 



Mr. W. B. Storey. Jr.. in discussing a paper by 



id Location, says:* 



On the Southern Pacific System the location Is trans- 

 ferred from the paper to the g.ound. no: by .aling. but 

 by calculation. Each tangent I* fixed, and the connect- 

 ing curve* are all calculated in the o.llce by carrying ibe 

 line from one fixed tangent around through the prelim- 

 inary to the next .an gent Thee calculated notes are 

 then gives to a machine known as the locating party 

 and put on the ground by It. 



The writer does not remember having seen else- 

 where any reference to the calculation of field 

 notes; but In various articles on railroad location 

 he has noted direct or implied reference to scal- 

 ing. 



To make clear what Is meant by scaling and by 

 calculating, and to show the advantage of calcu- 

 lating over scaling, let us find, by the two 

 methods, the station and "plus" via the prelimi- 

 nary and via the location f<>r the check point A. 

 Fig. 1. the first crossing of the location and pre- 

 liminary which have a common starting poi 



BT 8CALJNO. The angle at Pi. between pre- 

 liminary and location. Is scaled In the course of 

 preparing the r 



k-Mtlng a check or 



Tran.. Am. Roc C. .. Vnl X\ 



