Chain Bridge at Falls of Schuylkill

Chain Bridge at Falls of Schuylkill was an 1808 chain suspension bridge built across the Schuylkill River, north of Philadelphia, Pennsylvania. Designed by James Finley, it became the model for his later chain suspension bridges.

The Chain Bridge had two spans: an eastern one of 200 feet (60.96 m), and a western one of about 100 feet (30.48 m).[1] The bridge's chain cables were carried by paired A-frame wooden towers on its east and west abutments, and a third pair built atop a stone pier rising from the river. An 1811 painting by Thomas Birch at the Historical Society of Pennsylvania clearly shows the two unequal spans.[2]

Its chains were made of 1.5-inch-square (3.8 cm) iron bar wrought into links of between 8 and 12 feet (2.44 and 3.66 m) in length. These were used for both the cables and the vertical suspenders. The suspenders were attached to 10-by-5-inch (25.4 cm x 12.7 cm) wooden joists spaced 10 feet (3 m) apart, and covered by a 2.5-inch-thick (6.4 cm) wooden deck that was 18 feet (5.5 m) wide and 306 feet (93.26 m) long.[3]

Although Finley patented his Falls of Schuylkill bridge and publicized it widely, it was not a success. "Part of the superstructure broke down in September, 1810, while a drove of cattle was crossing it, and in January, 1816, the bridge fell down, occasioned by the great weight of snow which remained on it, and a decayed piece of timber."[5] The Chain Bridge was replaced by a wooden covered bridge in 1818.[6]

The Reading Railroad Bridge (built 1853-56, still in use) crosses the Schuylkill at the approximate location of the Chain Bridge.

See also

References

  1. ^ The above image shows only the top half of Strickland's elevation. Cut off is the image's caption: "200 ft. span".
  2. ^ Illustrated in Nicholas B. Wainwright, Paintings and Miniatures at the Historical Society of Pennsylvania (Philadelphia: HSP, 1974), p. 131. A copy of this painting by Russian diplomat Pavel Svinin is at the Metropolitan Museum of Art. Avrahm Yarmolinsky, Picturesque United States of American, 1811, 1812, 1813, Being a Memoir on Paul Svinin (New York: William Edwin Rudge, 1930), plate 35.
  3. ^ The Portfolio, p. 449.
  4. ^ William Strickland's elevation has been misidentified as being of Finley's Jacob's Creek Bridge (1801), but that bridge's widest span was 70 feet, not the 200 feet shown in The Portfolio. Strickland's elevation also appears in Joseph Jackson, Encyclopedia of Philadelphia (Harrisburg: National Historical Association, Inc., 1931), vol. 2, p. 412, with the caption: "Chain Bridge over the Schuylkill at the Falls".
  5. ^ Jackson, p. 412.
  6. ^ Jackson, p. 411-12.