Engineering Wonders of the World
Volume I

274 ENGINEERING WONDERS OF THE WORLD. sents another Manhattan Valley Arches. was built in 1886-89. The two arches, each mad© up of six I-shaped ribs 13 feet deep, have a clear span of 510 feet and a rise of 9T8 feet. The bridge closely resembles the more renowned Eads’s bridge referred to above. A less imposing pair of bridges, found in Manhattan Valley near West 130th Street, pre- contrast, a contrast of aesthetic effect. The Subway Arch, a glimpse of which is given in Fig. 29, glories in its plainness. The simple curves of its 170- foot span exhibit no effort at adornment; yet it cannot be denied that the structure pos- sesses a marked natural grace. Finally, there are serious proposals for three bridges of quite phenomenal dimensions in New York city, to which we must give at least a moment. The most recent proposal lias the best prospects of early realization. Three Pro- posed Monster Bridges. This is the Hell Gate arch bridge of the Pennsylvania Railroad, spanning 1,000 feet clear. Its location has been indicated on our map (Fig. 2). By glancing at the picture of the Washington Bridge (Fig. 27), and imagining a single arch replacing the two arches, we may get an idea of its enormous size. The arch would rise to a height of 300 feet above the water, though the railway floor would be but 140 feet up, being suspended from the arch. This structure is intended to span tho easterly channel of the East River from Long Island to Ward’s Island, and its viaduct approach would extend thence to Port Morris, using smaller spans to cross the other water spaces. The Henry Hudson Memorial Bridge (Fig. 31) is a reinforced concrete arch 703 feet in clear Fig. 26.—JOINING UP the Blackwell’s island bridge.