I9I0.] DAVIES— TUXXEL COXSTRUCTIOX. 167 



Broadway Subway near the surface, below that the Hudson and 

 ^Manhattan Tunnel, below that again the Pennsylvania Tunnels, and 

 for a cross-town line at a level below these. 



The Hudson and ^Manhattan Tunnels are the direct lineal 

 descendants of the original Hudson River Tunnels commenced in 

 1873. They are developed from the traffic conditions outlined 

 above. 



The original undertaking, if it could have been carried to com- 

 pletion at that time, w^ould, unquestionably, have proved unsuccess- 

 ful in operation. It was then contemplated to build this tunnel from 

 Fifteenth Street, Jersey City, about midway between the Erie and- 

 Lackawanna Railroads to a union station at Washington Square, 

 New York, and to transport therein the steam engines and trains of 

 all the railroads terminating on the westerly shore of this river. 

 The method of construction adopted by Colonel Haskins, while 

 feasible for working in the river silt, would never have been ade- 

 quate to complete the work, and it is only in the past decade that the 

 art of engineering has reached the point of providing the methods 

 for construction and of operation suitable to the completion of this 

 work and to meet the demands of the travelling public, within the 

 scope of modern operation. 



In the subject matter following, describing the methods of tun- 

 nel construction, the work of the Hudson and Manhattan Railroad 

 tunnels is directly considered, but except in size of structure, and 

 as providing for totally different types of equipment and operation, 

 the matter is in every respect applicable to the work on the Penn- 

 sylvania Railroad tunnels, and it may be noted that the ratios of 

 tunnel sizes to weight of equipment are almost the same in the two 

 propositions. The Hudson and Manhattan system comprises four 

 complete tube tunnels under the Hudson River, a belt line con- 

 necting the principal steam railroads terminating in Jersey City 

 and Hoboken, and two terminals in New York City — one up-town 

 and one downtown. It is essentially a distributing and collecting 

 terminal in New York for the transportation lines in New Jersey; 

 and a distributing and collecting agent in New Jersey for the people 

 of New York. Its building has involved more varied character of 

 construction than any underground project ever executed, and cer- 



