Adam Soule, the chief scientist for Deep Submergence at Woods Hole, says it was this meticulous attention to detail that helped Alvin avoid having even a single serious accident after more than 5,000 dives. “We don’t develop prototypes,” says Soule. “All the technology we develop has to be bulletproof, so there is a lot engineering that is done before anything happens to the submarine. Yet there has been some close calls. Only a few years later Alvin was commissioned, a mechanical failure on his carrier ship caused him to fall into the ocean and he began to sink with three crew members inside. The crew narrowly escaped, but it took a year to recover Alvin from the bottom of the ocean.
Alvin has been in service for nearly six decades, but due to regular teardowns and rebuilds, the submarine piloted by Strickrott has little more than one name in common with its ancestor. For philosophers, Alvin remind him Theseus ship, an ancient thought experiment in which the planks of a ship are torn off and replaced one by one until nothing remains of the original. Over the years, Alvin has been improved several times in order to be able to transport researchers ever deeper into the ocean, spend more time in depth and carry more samples taken from the seabed. But until its most recent renovation, AlvinThe sea’s depth rating only gave it access to about two-thirds of the seabed. There was a lot more ocean to explore.
AlvinThe current upgrade is the second and final phase of a review that began almost ten years ago. Funded by a $ 40 million grant from the National Science Foundation, the first phase laid the groundwork for further improvements that would extend the submarine’s maximum depth from 4,500 to 6,500 meters, which is deep enough to cover 99% of the world’s seabed. At the end of this phase in 2013, many Alvin the components were already evaluated at the full depth of 6,500 meters, including the troop carrier of the submarine, a cramped titanium alloy sphere. But Alvin had to wait to venture into these depths until the final upgrades were completed in the second and final phase of the upgrade this year. “In 2013, around 70% of the submarines were replaced,” says Strickrott. “We knew we were going to be operating for a while before we finished the last few pieces, which we are doing now.”
After Woods Hole engineers put the finishing touches on Alvin in the spring, he will undergo a rigorous testing process to prepare for his first dive to 6500 meters. The first tests of the complete vehicle will be unscrewed and will demonstrate that Alvin can operate its life support systems for 24 hours without creating harmful gases that would endanger its passengers. Then a crew of three will spend 12 hours inside Alvin on the shore to test his life support system again. If all goes well, the Navy will give the Woods Hole crew the green light to begin testing in the water.
Next September, Alvin will be transported by boat to Puerto Rico, where it will begin its first wet tests. Over the course of a week, Alvin and his crew will dive progressively deeper in approximately 500-meter increments. At the end of the week, Alvin will have reached its maximum depth and touched the seabed in the abyssal trenches off the Puerto Rican coast. If the tests go well, the Navy will officially authorize Alvin for regular crewed expeditions to this depth, and the submarine would spend most of the next five years in the water around the United States conducting scientific research until it was brought back to Massachusetts for its tuning regular.