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Fries Avenue

“When you do underground work, there are a lot of variables. When you do tunnels, and go down 100 feet, you encounter things you didn’t know were there,” says Cal Terrasas, one of Pacific Boring’s founders. Trenchless construction and tunneling work are no easy endeavors, especially when happening 100 feet under the Pacific Ocean.

In 1998, Pacific Boring and Mladen Buntich Construction’s joint company, Nada Pacific, tackled the Fries Avenue Force Main Channel Relocation project. The crew was tasked with installing a tunnel under the Los Angeles harbor, beginning at the cargo terminal and ending at Terminal Island. The tunnel consisted of a single drive 830 linear feet long of 46” Permalok steel casing.

It was quite alarming when excavation began on the project. A serious leak developed in the frozen wall of the shaft 84 feet down. Water and sand started pouring into the shaft at a dangerous rate. The crew were concerned that the entire shaft could collapse and cause damage to the terminal. The excavated soil piled adjacent to the shaft opening on the surface was quickly dumped back inside to avert the danger of collapse.

Once the shaft was completed, the tunnel crew moved on site and launched the advancing tunnel through the frozen shaft wall under the ocean.  The crew could hear the propellers of the ships passing through the harbor above as they worked.

When the tunnel boring machine reached the receiving seal, another difficult problem arose: the seal could not be adjusted to center on the machine due to the immense water pressure. Water rushed into the receiving shaft. Scuba divers were brought in to try and remove the seal, center it on the machine, and weld it in place. They did their job, or so it seemed, and the water was pumped out of the receiving shaft. Unfortunately, the divers did not successfully weld the seal in place. The shaft continued to fill with water.

Cal began to worry that the water pressure might blow the seal completely off, causing a catastrophic amount of water and sand to gush into the shaft. Time was of the essence and Cal knew what had to be done. He volunteered to go down into the shaft and reinforce the seal’s weld himself. As he prepared to enter down into the shaft, the air fans failed causing a thick fog to rise up. It was impossible to see the bottom of the shaft. They ordered another fan to be brought in, but the project was on edge and could not wait. Cal and Barry, Pacific Boring’s Superintendent who was just visiting the view the project, were lowered into the freezing, foggy, dark pit in an attempt to save this project.

Cal and Barry reached the bottom of the pit and unloaded the welding gear. Then, Barry was raised about 30 feet up in the shaft so that he could relay signals from Cal to the surface if something went wrong.  Cal entered the shaft as ice-cold water spurt through the seal. Cal began welding the seal. After a few hours, Cal’s body started to freeze up. He asked to borrow a wetsuit from one of the divers so he could continue welding through the biting cold.
The conditions in the receiving shaft were so precarious that Cal’s good friend Lee, the general contractor’s project engineer, could not watch. Instead, he paced the dock for hours far away at the launch shaft side.

For twenty hours straight, Cal worked and shivered. He reinforced the seal weld, assembled the receiving cradle, disassembled the tunnel boring machine, and attached it to the lift so it could be hauled to the surface. After everything was done, only then did Cal emerge from the pit.

“It was the most difficult project I had worked on up to that point,” said Cal.

Cal’s wife, Judy, didn’t learn about this perilous endeavor until long after it took place. And she did not hear it from Cal, she actually overheard individuals reminiscing about the adventure at a company Christmas party.

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