The Historic Caddo Lake Drawbridge
Mooringsport, Louisiana

The Engineers
John Alexander Low Waddell

John Alexander Low Waddell (1854-1938), a native of Canada, received a degree as Civil Engineer in 1875 from Rensselaer Polytechnic Institute. In the same year he worked as a draftsman for the Marine Department at Ottawa, Canada, and, in 1876 and 1877, served as an engineer with the Canadian Pacific Railroad. In 1878, Waddell returned to Rensselaer and spent two years on the faculty. Between 1880 and 1882, he worked as Chief Engineer for Raymond Campbell Bridge Builder of Council Bluffs, Iowa, and received a Masters in Engineering from McGill University of Montreal, Canada. In 1908, this same institution awarded him a doctorate in engineering.

In 1882, Waddell accepted a position as professor of civil engineering at the Imperial University of Tokyo. For his service, the Japanese Emperor awarded him the Knight's Cross of the Order of the Rising Sun in 1885. In 1886, he returned to the United States. The following year he established a practice in Kansas City, Missouri as a bridge designer and consultant, and for the next half century, was "one of the best known bridge engineers in the United States" (Dictionary of American Biography).

According to the Dictionary of American Biography, "In his bridge work Waddell was noted for his boldness in innovation combined with a careful attention to detail." He designed bridges in the Unites States, Japan, Canada, Mexico, Russia, China and New Zealand. Waddell was also a prolific writer. His 1916 two-volume "Bridge Engineering" became the standard work on the subject.

Waddell’s work set standards for elevated railroad systems and helped develop materials suitable for largespan bridges. His most important contribution was the development of the modern vertical-lift bridge. His patented design was first used in 1893 for Chicago’s South Halsted Street Bridge over the Chicago River; he went on to design more than 100 other movable bridges.

Waddell was a widely published and respected writer on bridge design, and an advocate of quality training of engineers and the professional status of engineers.

The Caddo Lake Bridge is one of two Waddell designed bridges in Louisiana. The other being an "A" Truss Railroad Bridge crossing Cross Bayou in nearby Shreveport which has been donated by Kansas City Southern Railway to the City of Shreveport.
John Lyle Harrington
In 1907, J.A.L. Waddell formed a partnership with John Lyle Harrington (1868-1942), a skilled civil and mechanical engineer who was largely responsible for reworking Waddell's vertical-lift invention into a rational, well-integrated design. In its essential form and dynamics, the "Waddell and Harrington version" remained true to the original 1892 design. Before the partnership dissolved in 1914, Waddell and Harrington designed about 30 vertical-lift spans for highway and railroad crossings. After they parted company, both men continued to work in the field, and Harrington's new office, Harrington, Howard, and Ash, became particularly well known, as was its successor, Ash, Howard, Needles and Tammen.

The engineering firm is still in operation today under the name of Harrington & Cortelyou, Inc. with its home office located in Kansas City, Missouri.

Below is a timeline of the firm's origin

J.A.L. Waddell
Waddell & Hedrick
Waddell & Harrington
Harrington, Howard & Ash
Harrington & Cortelyou, Inc.
Consulting Engineers
(1928 to Present)