250 



ENGINEERING IN 1892. 



BRIDGE OVER PECOS RIVER, SOUTHERN PACIFIC RAILWAY. 



Orleans. The new work includes a bridge over 

 Pecos river cafion in Texas, a tremendous ra- 

 vine 400 feet deep and nearly half a mile wide. 

 The bridge, as nearly completed, is shown in 

 Fig. 2. It is surpassed in height by only one 

 other structure of the kind in the world, name- 

 ly, the Loa Viaduct, in Bolivia, described in the 

 ''Annual" for 1889, and falls short of this only 

 by about 8 feet. Its height above the stream 

 is 328 feet; length, 2,180 feet; width at floor, 20 

 feet, providing for a single track and footways 

 for employees. The material is steel, the pi'in- 

 cipal tower being 321 feet 6 inches, including 

 the limestone foundation. The viaduct has 48 

 spans all told, the central or channel span being 

 a cantilever of 185 feet, while the others are 

 plate girders, alternating 35 and 65 feet long. 

 The towers are all 35 x 100 feet at base and 

 10 x 35 feet at top. The erection of the iron- 

 work was begun in November, 1891, and finished 

 during the summer of 1892, under the super- 

 vision of the Southern Pacific engineer corps. 



Moving a Bridge Tower. An interesting 

 engineering feat was accomplished late in De- 

 cember in moving a large drawbridge tower on 

 the Harlem river. The structure is of iron lat- 

 tice work 126 feet high, 48 feet 6 inches wide, 

 and 34 feet long at the base, tapering upward 

 wedgewise to a horizontal tiebeam at the top of 

 its two vertical main pillars. With its accessory 

 machinery it has for many years done the work 

 of raising and lowering the drawbridge that car- 

 ries the trains of three great railroad lines, name- 

 ly, the New York Central, the Harlem, and the 

 New York and New Haven roads. The traffic 

 by river and rail has far outgrown the capacity 

 of the bridge, and a new one is in course of con- 

 struction. Since no interruption of traffic is ad- 



missible, a temporary structure must be erected 

 until the new bridge is ready for use. The most 

 feasible plan seemed to be to move the tower to 

 the line of the temporary bridge. This was ac- 

 complished under the management of Mr. May- 

 Ian, foreman for Coffrode and Savior, the original 

 builders of the tower. Two rows of piles were 

 driven, topped with heavy stringers and rails, and 

 the tower, stripped of movables, but still weigh- 

 ing 180 tons, was jacked up 3 feet, rails connect- 

 ed with those on the piling were laid under it, 

 and the tower was lowered into position. Dix- 

 on's plumbago lubricator was used on the rails, 

 and with the aid of a powerful hoisting engine 

 and immense sheave blocks the great tower slid 

 easily on its ways and was moved back and forth 

 at the experimental trial at the rate of more than 

 2 feet a minute. Eventually it was moved with- 

 out a hitch to its new site, and set to work oper- 

 ating the temporary draw. The new bridge now 

 under construction will carry four tracks in con- 

 tinuation of the present Fourth Avenue system, 

 and will be built to meet the requirements of the 

 United States engineers who have in charge the 

 improvements that will soon change Spuyten 

 Duyvel creek from an insignificant inlet to an 

 important commercial highway. 

 The Norwegian Ship Canal. One of the 



freatest of modern engineering works is un- 

 oubtedly the magnificent canal, now completed, 

 which connects the great lake system of Tele- 

 marken with the sea near Christiania. It forms 

 a water way of more than 85 miles, traversing 

 half of southern Norway from east to west. It 

 forms, in fact, a beginning of what may be re- 

 garded as a main highway between the east and 

 the west coast of the Norwegian peninsula. The 

 work was begun in 1861, when the first of the 



