London Bridge
- Five-span reinforced concrete bridge built using soffit
- Facing stone was match-marked to be placed in their original relative locations on the bridge.
Lake Havasu City would be virtually unknown today if it weren’t for Robert McCulloch. In the early 1960s, the city’s site was a barren World War II auxiliary airfield with no population to speak of. McCulloch, an industrialist and a developer, bought the historic bridge at auction and decided to make it the centerpiece of his new development at Lake Havasu City.
In 1969, M. M. Sundt’s heavy civil construction division was already working in the Lake Havasu area on a project to improve Arizona State Route 95, so the company bid on the London Bridge job, and was successful. The five-span reinforced concrete bridge was built entirely on dry land using a technique called soffit fill. Sundt was one of the companies that pioneered soffit fill in the 1960s, a technique frequently used to construct bridges today. In short, soffit fill involves building up a pile of earth so that the mound is as high as the bottom of the bridge to be constructed. Crews form and place a concrete waste slab on top of the mound, and then the entire bridge is built on top of it. When the bridge is finished, the dirt is excavated from beneath the structure.
Although there were 130,000 tons of granite in the original bridge, McCulloch only bought 10,000 tons of the outer facing blocks. Most were cut down to form a cladding for the new structure. When the bridge structure was completed, Sundt received a separate contract to apply the facing stone, which had been match-marked so they could be placed in their original relative locations on the bridge. The stones weighed between 1,000 to 8,000 pounds. Sundt was then contracted to build the one-mile-long channel that cuts across the peninsula to place a watercourse under the bridge.