Alvin Gets an Interior Re-design
Sub’s new sphere offers room to add a bit of comfort
For more than four decades, scientists have foregone a few creature comforts to see animals, or volcanoes, or shipwrecks at the bottom of the sea.
(From WHOI / by Amy E. Nevala) — On a typical dive in the research submersible Alvin, a pilot and two scientists climb through a narrow hatch into a hollow 6-foot-diameter titanium sphere nestled in the front. Once sealed inside, they have no room to stand up, no seats, and no bathroom. For up to eight hours, they sit on thin pads on the floor and peer out windows, or viewports, the size of teacup saucers. The pilot drives while perched on a small metal box.
“It sort of equates to sitting in a phone booth with two of your closest friends, all day long,” said Patrick Hickey, Alvin operations manager at Woods Hole Oceanographic Institution (WHOI), who has logged 635 dives as the sub’s pilot.
But now engineers at WHOI have begun planning a multimillion-dollar overhaul that will ultimately allow Alvin to stay down longer (up to 12 hours) and dive deeper (6,500 rather than 4,500 meters). To withstand greater pressures at greater depths, a new, stronger titanium sphere has been forged. It is 3, rather than 2, inches thick, with an interior diameter that is 4.6 inches wider than Alvin’s current sphere. That increases the interior volume by nearly 20 percent, from 144 to 171 cubic feet, and that additional space has opened up a range of new possibilities.
“The buzzword is ergonomics,” said Anthony Tarantino, a former Alvin pilot. He is part of a team of marine engineers at WHOI who have donned the hats of interior designers to make Alvin, a workhorse of the oceanographic community, a little more comfortable.
Even before thinking of a redesigned interior, engineers on the project considered the shape and weight of every item that must fit inside the submersible on each dive. All told, the list includes about 300 items. Every power, navigation, and alarm system panel, storage shelf, camera control device, ethernet switch, emergency flashlight, and even the pilot’s small seat must be weighed to ensure that Alvin has enough buoyancy material to keep the submersible upright and stable during a dive.
Once all the equipment is inside, what space remains goes to the pilot, the scientists, and the small bags of items that they bring down with them (typically, a snack, notepads or other recording devices, and extra warm clothing).
Fitting it all inside the sphere is like piecing together an enormous puzzle inside a big ball. In a laboratory on a dock in Woods Hole, engineers created a prototype fiberglass version of the new sphere to to give people a sense of the available space and help them figure out where everything might go.
To represent each item that will go into the sphere, engineers designed and built mock-ups of computer monitors, video displays, handheld cameras, and dozens of other pieces of equipment—all out of cardboard—to help work out how to fit people and components harmoniously together.
Earlier this year, a group of six WHOI scientists who routinely use the submersible for deep-sea research worked with the project’s managers to develop an initial layout. Most notable were the addition of two more viewports, for a total of five, each with a diameter of 7, rather than 5, inches. With larger fields of view, scientists will be able to see outside and direct their research more easily.
Perks for pilots
The goal was to use their proposed layout as a draft to gather reactions from other Alvin users. This spring, Chris German, chief scientist for deep submergence at WHOI, distributed a 20-question survey to Alvin users, seeking their opinions on changes they would most like to see in the new sphere’s interior. More than 110 biologists, geologists, microbiologists, geochemists, and engineers responded.
Of those who replied, more than half ranked comfort while working on the seafloor as a very important issue, though several noted that the pilots’ comfort should rank higher than that of their scientific “passengers.”
“The pool of pilots should decide what is the best configuration for them,” wrote one respondent. “They are rock stars [who] can make or break sampling (taking fluids, chemicals, rocks or organisms from the seafloor). They need to be comfortable.”
“Make them happy!” wrote another.
With larger viewports, pilots will have more visibility to guide the sub and use Alvin’s manipulator arms to conduct sampling and experiments. And easy-viewing computer monitors will replace switchboards and gauges that pilots continually keep their eyes on to check power, communications, propulsion, and alarm systems.
“The goal was to reduce fatigue,” Tarantino said. “It’s mentally draining for pilots to be constantly sweeping their eyes to different gauges, then looking outside through the viewports, then sweeping the interior again. A pilot does this dozens and dozens of times during each dive.”
Seats, sights, and heights
The survey also asked people about their height and vision. German said the information will help make the interior set-up of the sphere more user-friendly, and when possible, adjustable to accommodate different needs.
“Being on the smaller side is definitely a plus when you dive in Alvin,” said Bruce Strickrott, who, at 6 feet 3 inches, is currently Alvin’s tallest pilot.
Half of the respondents reported that they are nearsighted. “During the average dive, people are constantly looking out of a viewport then back to a computer screen or notepad to record what they are seeing, or to interior video screens showing live video feeds to areas around the submersible,” German said. “It means they are constantly refocusing their eyes. That’s important to know because it helps us decide where we are going to put key components like video monitors,” especially in relation to where scientists will position themselves inside the sphere.
As to how they will position themselves, scientists will have more options. The new locations of the viewports necessitated changes in seating, which gave engineers an opportunity to build in some more comfort. Now, passengers often sit on the floor, with their heads on opposite sides of the sphere and their legs poking into shared space in the center, trying not to kick the pilot’s metal box/seat. To get people off the floor, engineers have proposed adjustable benches that allow passengers the choice of kneeling, sitting, or lying flat.
Try it on for size
In May, scientists and engineers who convened at WHOI for a national Deep Submergence Science Committee meeting took the opportunity to offer feedback, taking turns climbing into the prototype sphere. Stace Beaulieu, a biologist at WHOI who has made 13 dives in Alvin, lay with her belly flat on one of the two adjustable benches. She sat cross-legged, then flipped the seat so that she could kneel. She pretended to type on a computer, write in a notebook, and speak into a handheld tape recorder—all part of the copious note taking that she and others undertake during each Alvin dive.
“The idea of being able to move around is very comforting,” she concluded after climbing out. “In the current sphere, your knees are always cramped. Or if you all decide to stretch your legs out in the middle, you have to agree to have a little bit of a hog pile.”
“But in this,” she said, nodding at the prototype, “you could relax a little bit, have a little more space for stretching.”
Nearby, Tarantino noted the scientists’ comments about the newly forged sphere. Engineers started with two huge, barrel-shaped ingots of titanium weighing 34,000 pounds, about the equivalent weight of a large school bus. The ingots were reshaped into two giant hemispheres that were machined and welded together. The resulting sphere weighs approximately 12,000 pounds.
The sphere has spent the last year undergoing treatments to ensure its reliability. Tarantino said it must be free of any deformities that could weaken its structure and potentially cause it to crumple under pressure. At maximum depth, there will be roughly 10,000 pounds of pressure on every square inch of the sphere’s exterior, though for people on the inside, the air will remain at the normal atmospheric pressure found at sea level.
Built for depth, not for comfort
With such an expensive and carefully crafted investment, why not make the new sphere really snazzy by adding reclining leather seats? a reporter suggested. How about a few cozy cashmere blankets and an Italian coffee maker, which would fight a chill that comes from the average temperatures of 55° to 65°F inside the sphere? Tarantino laughed and shook his head.
Weight limits prohibit too many frills, he said. Safety considerations also add constraints. To prevent a fire inside the submersible, electronics must meet strict criteria before they are allowed in. Fabrics covering the foam pads also must be fire-resistant and made from a material that would not emit noxious fumes.
“We’re never going to be able to provide luxury,” said German. “It’s not like flying business class.”
But lack of comfort is part of the experience, said German. Sharing a ride in Alvin bonds people, he said, in the same way that people sometimes feel a shared sense of accomplishment after making an arduous car journey.
“People know that they have endured one of the more uncomfortable rides on Earth to be a part of a really special group,” German said.
Tarantino said they plan to make final interior design decisions by late September, when a review panel at the National Science Foundation, which is funding the project to upgrade the U.S. research community’s only deep-sea human-occupied vehicle, will evaluate the feasibility of the design.
Hickey, Alvin’s operations manager, was confident that people would enjoy improved creature comforts. But he forewarned future passengers that they still won’t find one thing on board: indoor plumbing.