ENGINEERING. (RAILWAY BRIDGE AT CINCINNATI.) 



VIEW OF THE FORTH BRIDGE BEFORE THE SPANS WERE 

 JOINED IN THE CENTRE. 



creeping of the rails. The bridge substructure 

 includes four granite piers extending from a 

 point 3 feet below low water to 2 feet above high 

 water ; above this latter point limestone is used, 

 the whole resting upon caissons and the usual 

 crib work. The first soundings were made in 

 September and October, 1887, and the work was 

 begun on the caissons in January, 1889. The 

 depth of water at the piers was 18 feet when the 

 caissons were sunk into position, but such are 

 the changing conditions of the river that before 

 the work was completed the depth had increased 

 to 42 feet, and the force of the current was so 

 great that the anchorages twice gave way. 



Railway Bridge at Cincinnati. This fine 

 bridge forms an important link in the Chesa- 

 peake and Ohio system. Its interest as an en- 

 gineering work is chiefly due to the length of 

 the individual spans. There were no special 

 difficulties in the way, excepting the necessity 

 of avoiding obstructions to navigation. The 

 central span is 550 feet between centers of piers 

 and 84 feet between centers of cords ; this is 

 the largest truss span of this character that has 

 been constructed. The two spans flanking the 

 main channel are 490 feet each between pier 

 centers, with 75 feet between centers of cords. 

 These spans are all planned for a double-track 

 railway with two roadways and two sidewalks : 

 of course this renders it necessary to employ 

 construction of the strongest and most durable 

 description, and there is nothing, either in this 

 country or in Europe, that shows such heavy, 

 non-continuous trusses. All the main parts 

 are of steel, and the bracing in the lateral and 

 transverse systems, with the floor-beams and 

 stringers, are of wrought iron. The system of 

 connection between piers and posts is somewhat 

 novel. All the connections are central and are 

 designed so as to reduce sectional strains to a 

 minimum. The system, which may be termed 

 a web system, has been brought to its present 

 perfection by the Phoenix Bridge Company. The 

 total weight of the iron and steel in the three 

 principal spans is 10,000,000 pounds. The ap- 

 proach on the Kentucky side is 1,533 feet, and 

 on the Ohio or Cincinnati side nearly 2,300 feet, 

 including the many tracks divergent to freight 

 depots. The total structure, therefore, is one 

 mile long, and more than 20,000,000 pounds of 

 metal have been used in the entire work. Dur- 

 ing the construction of this bridge several floods 

 of exceptional height occurred, and large quan- 

 tities of drift brought down on the current and 

 lodging against the false work of the bridge often 

 threatened its destruction. At one time the 

 drift formed a continuous mass for more than 

 500 feet up stream from the bridge, and, in spite 

 of every precaution, a large portion of already 

 constructed work was swept away ; fragments of 

 the wreck were scattered for 50 miles down the 

 river. To prevent a recurrence of such a disas- 

 ter effective precautions were taken, and two 

 lines of heavy piling were run up stream from 

 each of the piers. These formed a V-shaped 

 protection with the acute angle nearly 600 feet 

 up stream. This protection proved to be. a com- 

 plete safeguard during several severe freshets. 

 So actively was the work of repair prosecuted 

 that five weeks after the day of the wreck the 

 entire false work was replaced and regular work 



