An inventory of bridges on Oʻahu, published in 1983, listed 127 built before 1940 and still standing.
Oʻahu’s 127 historic bridges are composed of five different types: reinforced concrete arch bridges, steel bridges, timber bridges, reinforced concrete deck girder bridges and reinforced flat slab bridges.
The historic steel bridges are further divided into three separate types; warren truss, steel girder and metal flume. A bridge is considered historic if built before 1940 and is associated with people and events that have made a significant contribution to the broad patterns of Hawaii’s history.
The Karsten Thot Bridge was identified as worthy of historic recognition.
It was built in Wahiawa over the north fork of the Kaukonahua stream in 1932, by the John L Young Construction and Engineering Company for a price of just over $65,500.
The bridge is named after Karsten Thot, who was a prominent community-minded citizen and it was built by a prominent Honolulu businessman, who was a prolific builder.
The bridge-building company merged with another construction company and upon completion of the Thot bridge called itself the Hawaiian-American Construction Co.
Built in the style of steel railway bridges throughout the continent, it is the only structure of its type in existence on Oʻahu; due to salt water erosion problems steel bridges were phased out on Oʻahu.
The structure is a Warren-type through-truss steel bridge, with a single span 210-feet in length and 40-feet wide, with a vertical clearance of the bridge is 13’5″.
Karsten Thot was born in Schleswig-Holstein, Germany, on Feb. 12, 1889. He came to Hawaii in 1904. Thot worked as a field supervisor for Hawaiian Pineapple Co.
In addition, an announcement in the paper noted, ‘Karsten Thot, manager of the Hawaii Preserving Company, has opened a butcher shop at Castner Station, near Schofield Barracks.’ (Honolulu Star-bulletin, July 09, 1915)
Thot died in 1932, the year the bridge was under construction. He was survived by a wife and three children.
He “was very active in community affairs when the Honolulu Board of Supervisors under Charles Crane asked if they could name the bridge after him. This was not carried out until Fred Wright became mayor in 1937. In 1974 a memorial plaque was placed on the bridge by the family.” (Thompson)
When built, the bridge was said to be an important transportation link between the North Shore and Honolulu, contributing to the growth of Wahiawa.
That ultimately changed after the construction of the H-2 freeway, when Kamehameha Highway no longer was “the primary circum-island road.”
Recently, critical emergency structural repairs have been made to the 80+-year-old steel bridge, including replacing rivets and repairing and replacing steel beams.
(Lots of information here from a report by Bethany Thompson, Honolulu-gov and Watanabe, Star-Bulletin.)