PRR Zoo Junction Custom Kodak Photo Enlargement

From www.railphotoexpress.biz; Zoo Junction is an important junction on Pennsylvania Railroads (Northeast Corridor)Main Line in Philadelphia, Pennsylvania where The the Northeast Corridor meets the Keystone Corridor (ex-Pennsylvania Railroad main line). Zoo Junction was a flying junction, where multiple tracks cross one another by bridge to avoid conflict with other trains. In 1870 the PRR built the Connecting Railway from Frankford Junction to Zoo to bypass congested street running in Philadelphia. Instead of reaching the city directly from the north, the Connecting Railway turned west, crossed the Schuylkill River on a stone arch viaduct and then turned south to join the Pennsylvania Railroads Main Line at Mantua Junction. In 1935 the interlocking reached its final form in conjunction with electrification and the construction of Zoo Tower and Substation,and 30th Street Station and PRR Suburban Station. In Between Zoo Tower and the river was the Philadelphia Zoo, which gave the interlocking its name. Photo Credit, Library of Congress.