OPEN-CUT TUNNELING METHODS 199 



Viaduct. A considerable portion of the double track branch 

 lines north of 103d St. will be viaduct, or elevated structure. 

 The viaduct construction on the West^Side Line will extend, in- 

 cluding approaches, from 122d St to very near 135th St. 

 Of this distance, 2,018 ft 8 ins. will be viaduct proper, 

 consisting of plate girder spans carried by trestle bents at the 

 ends, and by trestle towers for the central portion. The 

 columns of the bents and towers are to be built up bulb-angle 

 and plate columns of H-section of the same form as those used 

 in the bents inside the subway. The approaches proper will be 

 built of masonry. The elevated line proper consists of plate 

 girder spans, supported on plate girder plate cross girders 

 carried by columns. 



Stations. Many stations will be built along the line. 

 These will be located on each side of the street. The 

 entrances at the stations will consist of iron framework, with 

 glass roofs covering the descending stairways. The passage- 

 ways leading down will be walled with white enameled bricks 

 and wainscoted with slabs of marble. The stations for the 

 local trains will be located on each side of the road close to the 

 walls, since the outside tracks are reserved for the local trains, 

 while the middle ones will be reserved for the expresses. The 

 few stations for the express trains will be located between the 

 middle and outside tracks. Stations will be provided with all 

 the conveniences required, having toilet rooms, news stands, 

 benches, etc., and will be lighted day an<l night by numerous 

 arc lamps. 



General. The contractor is compelled to complete the 

 work in four and one-half years, but he has promised to have 

 it in full running order within three years. There is no diffi- 

 culty in doing this, since the great extension of the road and 

 the great width of the avenues under which it runs allow work 

 all along the line at the same time. The work, briefly summar- 

 ized, comprises the following items: 



