Global Diving & Salvage's California Region Completes Caisson Cut-Off Project
This June, Global completed a complex caisson cut-off job in the California region. With a dedicated dive team, they were tasked with diving over forty feet below the riverbed, where they meticulously burned through a sixty-inch caisson, preparing it for removal.
The Objective
The objective of this project was to complete the cut-off of a steel caisson (pictured above), which could be seen twenty feet above the ground and extended over forty feet below the surface. In order to accomplish this project, the diver was lifted in a Cherrypicker to the top of the caisson, then was able to make their descent.
Mastering Zero Visibility
Initially, the visibility underwater was approximately five feet, allowing the divers to see their surroundings to some extent. However, as the burning process began, the visibility rapidly decreased to zero feet. This meant that the divers had to rely on their training, experience, and dive team to safely complete the cut in complete darkness.
Overcoming Rock Solid Obstacles
In addition to the challenging conditions of low visibility, the divers faced the obstacle of the caisson being located right against solid rock. This made it a challenge for cutting in that it was difficult to determine where the metal caisson ended and where the rock began. However, Global's expert dive team took on the task with a slow and methodical approach. They took their time, ensuring that they thoroughly cut through every inch of the metal despite aforementioned challenges. The divers understood the importance of not moving on until they were absolutely certain that the cut was completed entirely. This detailed and patient approach allowed them to navigate the task and ensure the job was done to the highest standards of quality and safety.
Safety Highlight
- Have a Plan A, B, and C -
A significant safety highlight of this project was the presence of multiple measures in place to ensure the divers' safety. They implemented various methods to retrieve a diver from the Caisson if necessary.
Firstly, they had a crane available, which could be used to lift the diver out of the Caisson. Secondly, there was an emergency davit, which is a mechanical device designed for personnel rescue. The divers could utilize this davit system to lift themselves out of the Caisson. Additionally, the team had a contingency plan involving water pumping, where they could pump water into the Caisson, gradually raising the water level until it reached the top of the Caisson. This method would effectively equalize the pressure inside and outside the Caisson, allowing the diver to exit safely.
