The two Delaware Memorial Bridges have been equipped with a $35 million dehumidification system to extend the life of their main extension cables, according to the Delaware River and Bay Authority.
It is the second bridge system in the United States with a dehumidifier. The first was installed in 2012 on the William Preston Lane Jr. Memorial (Bay) Bridge in Maryland. There are 25 suspension bridges in the world with dehumidification systems; the first was placed in 1998 on the Akashi Kaikyo Bridge in Japan.
To install the system, air-tight wraps were placed around the main cables that support the bridges’ decks. The system also includes injection and exhaust ports. Dehumidification plants are installed inside the bridges’ anchorages. The system is equipped with remote sensors so its operations can be monitored.
The Delaware Memorial Bridge to Delaware from New Jersey opened in 1968. The New Jersey-bound memorial bridge opened in 1951. American Bridge Company of Coraopolis, Pennsylvania, was hired by the authority in 2016 to build a cable-preservation system for both spans, and it is scheduled to complete work in spring.