The challenging task of repairing expensive underwater internet cables

Hello everyone and welcome back to the Fluctus channel. It's believed that over 850,000 miles of undersea cables are laid across the globe. While they vary significantly in size and type, most serve one of two purposes, communications or power transmission. Despite their technological sophistication, the processes of installing, repairing and maintaining these cables are incredibly demanding. The Iran Islands lie off Ireland's west coast. Because of their remote location and small size, they rely heavily on undersea cables to receive power, internet, and other communications from the mainland. In 2016, one of these cables broke, cutting off power to the islands. A company called ESB International was brought in to fix the damaged line. The repair required divers to work on the seabed while keeping the 500 megawatt connectors submerged. To manage this, ESB developed a specialized habitat repair unit that took years of training in pools and simulated settings to master. Even with this approach, the job remains complex. We have then subsequently tailored the habitat to suit a variety of different cables. cables. This particular cable that we're repairing is a three core AC cable so you can see from a large DC interconnector to a three core AC cable. The habitat solution that we've developed here has massive application across the broader global market. The habitat is lowered in two pieces positioned above and below the cable. Water is then pumped out creating a dry space where divers work using built-in gloves on the habitats walls. Beyond repairs, laying thousands of miles of cable in the first place, forced companies to invent novel engineering methods. One such firm, Boskalis Subsea, built a full-scale cable-laying ship equipped with several specialized systems. For instance, its flat-bottomed hull enables safe operation both close to shore and in open waters. It also has a rotating cable turntable capable of holding 5,000 tons. The ship uses a tensioner to lay the cable at the exact speed it moves along a pre-mapped route. These routes are designed to avoid natural hazards that might damage the cable. Once the ship reaches its endpoint, a winch lowers the cable through a pylon and brings it to the surface. A unique plow then drags the cable ashore, burying it as it moves to shield it from harm in shallow or sandy areas. With the rise of offshore wind farms, firms like Boskalis have become key players in transferring electricity from turbines back to land. In many projects, both ends of the cable installation occur simultaneously. As the specialized vessel trenches and lays the cable at sea, land-based teams unroll miles of cable to connect to substations. Offshore wind power marks a major leap in energy production. Because winds over water face fewer obstructions, offshore turbines generate more power than those on land. However, harnessing this energy requires advanced cables capable of withstanding the elements. Submarine cables are highly sophisticated and must endure some of the harshest, most corrosive environments on Earth. Therefore, they are designed to be far more resilient than terrestrial power or communications cables. The process begins with thick wires that are then coated by machines with multiple layers of protection. These wires are later bundled into larger assemblies and further insulated to maximize durability. U.S. Navy divers are highly trained specialists who perform crucial tasks in naval missions. The U.S. Navy has long been a leader in developing underwater and diving operations, driven by national defense and the need for specialized underwater capabilities. These divers have served since the mid-1800s, originally handling salvage, ship repairs, and construction. By the early 20th century, they began experimenting with deeper dives and staged decompression, reaching depths of 274 feet by 1915. After Pearl Harbor, Navy divers played a vital role in rescuing trapped sailors and retrieving munitions during massive salvage operations. Navy divers undergo rigorous training, which includes coursework on dive operations, management, and treatment for issues like decompression, sickness, and hypothermia. They're trained to use the MK-20 and MK-21 diving systems and Kirby Morgan helmets. Divers stay in contact with ships using voice communication through umbilicals, which also supply air. For deeper dives, emergency gas supplies, EGS, are carried as a backup. Navy divers are also known as CBs, derived from the abbreviation for construction battalions. Navy diving includes many specialties such as underwater ship maintenance, salvage, underwater construction, research, demolition, saturation diving, hyperbaric medicine, and diver training. Seabees use pneumatic jackhammers linked to surface air compressors via umbilicals. These tools are designed for submerged use with watertight housing and pressure compensating mechanisms. For underwater welding, they use arc welders with waterproof rods, special surface-powered machines, underwater lighting for visibility, and topside monitoring for safety. Both underwater construction and welding require surface-supply diving and close coordination with topside crews. Seabees, part of underwater construction teams, UCTs, also specialize in underwater demolition. They often remove damaged structures like pier foundations or submerged debris using carefully placed explosives. The goal is minimal collateral damage, achieved through detailed planning. UCT divers perform thorough surveys, place charges strategically, and coordinate with surface teams. Proper charge placement and timing are crucial, factoring in water pressure, currents, and the target's structure. These missions help ensure safe navigation and prepare areas for future development. Seabees also inspect submerged structures. UCTs use imaging tools and diagnostic equipment to assess deep-sea moorings and ocean installations. They inspect chains, buoys, and anchors, noting wear and checking integrity. For repairs, they employ underwater welding and cutting tools, along with precise measurement devices to ensure proper fit and alignment. They can swap out broken parts and perform routine maintenance to keep underwater infrastructure operational. UCTs manage these complex tasks with surface-supplied dive systems and underwater communication gear. Their expertise covers instrument installation, cable repair, pipeline maintenance, and regular inspections to ensure critical naval facilities remain functional. Another major responsibility for UCTs is salvaging lost vessels and aircraft. Sometimes aircraft crash or ships sink at sea. In such cases, CBs are tasked with recovering valuable equipment or entire structures. If recovery isn't feasible, they may be ordered to destroy them to keep sensitive materials from being recovered by others. On the 22nd of July, 2015 for example, they salvaged an F/A-18 Super Hornet that had fallen into the sea in the U.S. 5th Fleet's area. The jet had been swept off the USS Harry S. Truman's deck by unusually strong winds. Another case occurred on the 20th of November, 2023, when a Navy P-8 Poseidon maritime patrol plane skidded off the runway at Marine Corps Air Station Kaneohe Bay in Hawaii. The aircraft, from Patrol Squadron 4, VP-4, Skinny Dragons, ended up partially submerged in the bay after landing in severe weather. All nine crew members were safely rescued, but the plane became lodged in shallow water. Its recovery was complicated by nearby coral reefs and environmental concerns, necessitating a carefully coordinated recovery effort for the $140 million aircraft. Divers from Mobile Diving and Salvage Unit 1, MDSU-1, conducted detailed underwater assessments of the aircraft and nearby reefs. Their surveys helped confirm the plane's structural condition and shape a recovery plan that minimized environmental risks. The extraction used inflatable lift bags for stabilization, while a crane on a barge carefully hoisted the plane from the water. Divers attached salvage gear at multiple points to evenly distribute weight during lifting. The operation required precise teamwork between engineers, divers, and environmental experts. After nearly two weeks of planning and execution, the P-8 Ampere was safely recovered onto a barge on the 2nd of December, 2023. From the vital arteries of global communication to renewable energy infrastructure and military salvage missions, the world beneath the waves relies on a unique blend of advanced engineering, precise coordination, and human expertise. Companies like Boskalis and specialized teams like the U.S. Navy Divers continue to push the limits of what's possible underwater, ensuring that the essential systems we depend on above the surface remain functional, connected, and secure. That's the end of this video. I hope you enjoyed it. Make sure to subscribe to this channel so you don't miss any of our new content. See you next time.