“More people have been in space than have been at half the ocean’s depth,” notes Stockton Rush, a scuba diver and CEO of OceanGate Inc., Everett, Wash. OceanGate hopes to change that with Cyclops, a deep diving manned submersible for commercial markets that will be more than 80 percent carbon fiber by weight. Due to be completed in 2016, the first version of Cyclops will be able to reach depths of 3,000 meters. A later version will submerge 6,000 meters.
Here are a few quick facts about OceanGate’s Cyclops manned submersible:
Crew Members: 5
Carbon Fiber Hull: 17.8 cm thick
Max. Depth: 3,000 meters
Weight: 8,600 kilograms
Height: 2.3 meters
Speed: 3.5 knots
Payload: 500 kilograms
Length: 5.5 meters
Width: 3.3 meters
The idea for Cyclops began five years ago when Rush tried in vain to rent a submersible to explore the Puget Sound. Such rentals didn’t exist. So Rush, who has a background in aerospace engineering, bought a partly completed sub and finished it himself. Later, he found out that there are only seven manned deep diving submersibles in the entire world – all owned by governments or universities. “That didn’t compute,” he says.
Rush decided to find out why there were so few. He concluded that existing deep diving submersibles have all been built individually to meet specific research needs, so they are too expensive and specialized for commercial markets. He believed submersibles could be commercialized – and using advanced materials could aid the endeavor.
Cyclops will be the first-ever manned deep diving submersible with a carbon fiber pressure vessel. The cylindrical pressure vessel – where passengers sit – is placed between two end caps: One will be made of titanium, and the other will feature a 180-degree glass viewing dome.
Existing deep diving manned submersibles rely on titanium for the pressure vessel, making them heavy and expensive. “As the sub gets heavier your ship gets bigger, which means more crew and more cost,” says Rush. “Every pound you put in your sub ends up increasing your total system and deployment cost.” The weight of titanium also requires the addition of syntactic foam for buoyancy, which makes these vehicles ‘fat’ and slow, he adds.
Carbon fiber offers several advantages. Rush says it is cheaper than titanium, has similar in-plane shear strength and is one-third the density. You also can orient the fibers to maximize their strength. This last benefit is particularly advantageous in a submersible. “In a pressure vessel, the loads are very well known. They’re all going to be straight into the center,” says Rush. “So you have axial and radial loads and you don’t get torsional loads of any significance. You know exactly what the water is going to do, which allows you to optimize how you put the fibers so that all their strength is in the direction of that load.”