On September 3, traffic began moving across the new East Span of the San Francisco - Oakland Bay Bridge. Stretching 2,047 feet, the Self-Anchored Suspension (SAS) span is the signature element of the bridge and the world's longest such span.
The single, nearly mile-long main cable now supports the 35,200-ton decks of the bridge. The bridge's single 525-foot-tall tower echoes the height of the West Span's towers. Unlike traditional suspension bridges where the cables are anchored into the ground, an SAS bridge's cable is anchored in the roadways.
Through ingenious engineering, the span was constructed to last 150 years; more than double that of any other traditional bridge. Moreover, the span was designed to withstand high winds, as well as the largest possible earthquake that may occur within the next 1,500 years.
Such longevity requires regular bridge maintenance. Five moving scaffolds, known as "travelers," have been suspended from tracks beneath the bridge, providing safe access to workers, who will conduct bridge inspections, repairs and painting operations. The design of the travelers also enables them to capture maintenance-related debris such as paint chips and dust, water, sandblasting grit and paint overspray, preventing this material from falling into the bay 150 feet below.
The travelers, which move by pneumatic power from air compressors located in Oakland and on Yerba Buena Island, will carry crews laterally underneath the bridge at a rate of 20 feet per minute heading west and 50 feet per minute heading east. They allow personnel to complete the work as safely and efficiently as possible.
But before the travelers were installed, they had to first travel from the Westmont Industries plant in Santa Fe Springs, CA, where they were fabricated, to the Port of Long Beach, from where they were barged to Oakland. It would be the most challenging movement these travelers ever made. Because of the complexity of the transport, only a handful of companies in the world could accomplish this feat - or even dare to undertake it.
Fortunately, one of these companies was located near the manufacturer - Heavy Transport, one of the Bragg Companies of Long Beach. For more than 65 years, the family-owned business has specialized in over-sized, multi-dimensional and super-load hauling, providing a full-service approach to individualized transportation needs. Even for Heavy Transport, this would be a very demanding job that required 1,700 planning hours over the course of a year. Much of this time was spent coordinating the efforts of those involved with the travelers' fabrication, hauling, permitting and escorting and barging of the five sections. Regulatory approvals came from the Caltrans, the California Highway Patrol (CHP), and five cities and counties.
The largest of these parts measured 119-feet-long by 19-feet-tall by 16-feet, 4-inches-wide and weighed 51,000 pounds. Loaded, the dimensions jumped to 180-feet-long by 19-feet-tall by 19-feet high and a net weight of 70,000 pounds.
Even the smallest of the travelers, a 15-1/2-foot-wide bike and pedestrian path, called for a tricky transport. The unique load structure of the travelers required the use of Heavy Transport's Scheuerle Wide-Combi trailers with two 4-axle sections and a 39-foot drop deck insert to keep the height of the Traveler sections as low as possible while being hauled down city streets in Santa Fe Springs and Long Beach. The trailer configuration also needed a rigid support to keep the load's structure from twisting while also keeping it supported and tied down in four places on engineered mounting points. A custom-built heavy-haul Peterbilt tractor pulled each load.
For enhanced maneuverability; the eight sets of tires could articulate 60 degrees and move up and down. The Bay Bridge Public Information Office characterized these movements as "a giant game of steel doing the Limbo."
Zigging and zagging
Although the distance between the point of manufacture and the Port of Long Beach was about 20 miles, most freeways and city streets could not accommodate the load. Each piece had to be hauled on a complicated, zig-zag route with 21 turns that stretched 50 miles. Heavy Transport coordinated with its bucket truck service and CHP escorts to protect power lines, signals, trees and other obstructions. California requires such variance loads to be moved at night.
"It is a challenge in itself to move something this size," says Kevin Reese, Heavy Transport's Operations Manager. "It is an even bigger challenge to do it at night?”
Throughout the five consecutive nights of the move, Heavy Transport followed the Bragg Companies' Personal Accountability Safety Survey (PASS). Under this program, Bragg employees assess the risk, analyze how to reduce the risk and act to ensure safe operations before beginning any task. "Heavy Transport would like to recognize fellow SCSRA members West Coast Permit Service and Kenco Bucket Trucks for their help,” notes Reese. "Everyone helped to make this project a huge success.”
The original plan called for Heavy Transport to haul all five sections to the Port of Oakland. However, to save Caltrans time and money on the hauling of the travelers, Heavy Transport recommended the use of a barge. Due to the multiple entities and unions involved, others performed the loading and unloading of the units and Westmont Industries assumed responsibility for the transport by barge.
A few days after Heavy Transport completed its work, the barge sailed into the San Francisco Bay under the existing Bay Bridge.
This was a profitable lump-sum project that was completed ahead of schedule with zero incidents and zero lost-time accidents. The 250 total miles of the move itself required 400 man-hours.
"There were no unexpected issues on the move other than some wet weather,'' says Reese. “We find the best method is to plan the work and then work the plan.”
Source: ACT Magazine, October 2013 Issue