Scott Hanko
Turtle's Rear Propulsion
DSV-3 Turtle / DSV-4 Sea Cliff
The other two 6-foot diameter HY-100 steel spheres originally fabricated for the Alvin were later used for the Navy's Turtle (DSV-3) and her sister ship Sea Cliff (DSV-4), built to a design similar to the Alvin. Turtle had video and still cameras, two six-function hydraulic manipulators, and four large view ports. Sea Cliff had two 7-function hydraulically operated manipulator arms, three 11-cm view ports, and video and still camera systems.
The US Navy’s Deep Submergence Vehicle Turtle (DSV-3) and and its sister submersible Sea Cliff (DSV-4) participated in deep-sea search and recovery, oceanographic research, and underwater archaeology. Turtle and Sea Cliff were classified as manned, non-combatant, untethered submersibles. Each vehicle consists of a 6-foot diameter spherical pressure hull mounted on a metal frame. Inside the hull are the control electronics for navigation, lighting and video, and a life support system capable of supporting a crew of three for 72 hours. Located externally on the frame are the battery and hydraulic, ballast, trim, and propulsion systems. There are also two manipulators that allow the vehicles’ crews to handle and retrieve items on the seafloor.
The vehicles were launched on 11 December 1968 and accepted by the Navy in 1970. In keeping with the Navy’s submersible tradition, they are named for towns in the United States whose names are reminiscent of the ocean or sea life. Turtle was named after Turtletown, Tennessee, while Sea Cliff’s namesake is Sea Cliff, New York.
These DSVs are constructed of a fiberglass hull over the metal crew sphere, batteries and electric motors. The craft have television and still cameras, external lights, short-range sonars, and hydraulic remote-control manipulators. Turtle weighs 21 tons, Sea Cliff weighs 29 tons. These DSVs have an endurance of 8 hours at 1 knot, or 1 hour at 2.5 knots. Due to their limited range and endurance, their mother ship should be certain to remain in the vicinity.
Many submersibles control in-water trim by shifting mercury between chambers at either end of the vehicle. Mercury is also corrosive to aluminum, extremely toxic, requires extraordinary measures to prevent spills, and is difficult to clean up when a spill occurs. The Battelle "tungsten ball trim system" is the replacement trim system for Sea Cliff and Turtle. In this system sintered tungsten balls are the weight medium, stored in two stainless steel tubing coils at either end of the vehicle which are connected by a transfer line. Hydraulic fluid moves the balls through the tubing by means of slip flow past each ball, and plastic balls on either end of the daisy chain of tungsten balls provide a filler in the transfer tube when all the weight is shifted one way or the other.
Both submersibles were initially rated for a depth of 6,500 feet but received upgrades in the early 1980s. While the Turtle was rated at 10,000 foot operating depth, Sea Cliff had her original HY-100 steel crew sphere replaced in 1983 with a titanium sphere capable of 20,000 foot operations. Sea Cliff reached this depth for the first time in March 1985, during a dive in the Middle America Trench off the Pacific coast of Central America. This increase of 1500 meters over Alvin's limits provided access to 37% more of the sea floor. Turtle reached a depth of 10,000 feet on 3 October 1980, and Sea Cliff made it to 20,000 feet on 10 March 1985. At that depth, Sea Cliff was capable of reaching 98 percent of the world’s ocean floor, an area roughly six times that of the surface of the moon. As a result, Sea Cliff enjoyed the distinction of being named flagship for the “Year of the Ocean” in 1985.
Sea Cliff and Turtle were often called upon to locate and recover Navy equipment that was lost at sea. During its 20,000 foot sea trials, Sea Cliff was ordered to the site of a downed Marine Corps Sea Stallion helicopter. Operating at 1,500 feet, Sea Cliff used its manipulators both to retrieve pieces of the aircraft directly and to attach lift lines to other parts. Sections as heavy as 10,000 pounds were recovered. Overall, 61 dives were made, and 80 percent of the aircraft was retrieved. Most importantly, Sea Cliff found and recovered the remains of the aircraft’s four crew members for family burial. Similarly, in 1995, when a Navy swimmer delivery vehicle (SDV) was lost in 814 feet of water off Hawaii, Turtle found and retrieved it in an operation many thought was impossible.
Turtle and Sea Cliff had been based from Navy Landing Ship Dock (LSD), or, more commonly, from Navy oceanographic vessels. Any of them could be transported by C-5 aircraft, although such deployments were uncommon.
Since the end of the Cold War the submersibles Sea Cliff and Turtle were available for limited academic research through a cooperative arrangement between NOAA and the US Navy's Submarine Development Squadron Five in San Diego CA. These vehicles have expanded opportunities for peer-reviewed deep submergence research off the US west coast. Sea Cliff provided the science community with some additional access to the deep sea and permitted observations to depths approaching 6000 meters, a depth range otherwise only available by using ROV Jason or the other tethered vehicles of the National Deep Submergence Facility. This increase of 1500 meters over Alvin's limits provides access to 37% more of the sea floor, which represents an area that is greater than 90% of the surface area presently exposed on the continents.
Following the Navy's decision to decommission Sea Cliff, NAVSEA requested Woods Hole Oceanographic Institution (WHOI) to provide a technical assessment and costing of how to best integrate Sea Cliff into the National Deep Submergence Facility. Perhaps the most serious and biggest impediment to integrating Sea Cliff into the US deep submergence program was the lack of an adequate and stable funding base.
Turtle was retired and loaned to the Mystic Aquarium, Institute for Exploration, where it was placed on permanent display. Sea Cliff was turned over to the Office of Naval Research and as of 1999 was being stored at the Woods Hole Oceanographic Institute while its future was debated
Mystic Aquarium Mystic Ct.
Turtle's Rear Propulsion
DSV-3 Turtle / DSV-4 Sea Cliff
The other two 6-foot diameter HY-100 steel spheres originally fabricated for the Alvin were later used for the Navy's Turtle (DSV-3) and her sister ship Sea Cliff (DSV-4), built to a design similar to the Alvin. Turtle had video and still cameras, two six-function hydraulic manipulators, and four large view ports. Sea Cliff had two 7-function hydraulically operated manipulator arms, three 11-cm view ports, and video and still camera systems.
The US Navy’s Deep Submergence Vehicle Turtle (DSV-3) and and its sister submersible Sea Cliff (DSV-4) participated in deep-sea search and recovery, oceanographic research, and underwater archaeology. Turtle and Sea Cliff were classified as manned, non-combatant, untethered submersibles. Each vehicle consists of a 6-foot diameter spherical pressure hull mounted on a metal frame. Inside the hull are the control electronics for navigation, lighting and video, and a life support system capable of supporting a crew of three for 72 hours. Located externally on the frame are the battery and hydraulic, ballast, trim, and propulsion systems. There are also two manipulators that allow the vehicles’ crews to handle and retrieve items on the seafloor.
The vehicles were launched on 11 December 1968 and accepted by the Navy in 1970. In keeping with the Navy’s submersible tradition, they are named for towns in the United States whose names are reminiscent of the ocean or sea life. Turtle was named after Turtletown, Tennessee, while Sea Cliff’s namesake is Sea Cliff, New York.
These DSVs are constructed of a fiberglass hull over the metal crew sphere, batteries and electric motors. The craft have television and still cameras, external lights, short-range sonars, and hydraulic remote-control manipulators. Turtle weighs 21 tons, Sea Cliff weighs 29 tons. These DSVs have an endurance of 8 hours at 1 knot, or 1 hour at 2.5 knots. Due to their limited range and endurance, their mother ship should be certain to remain in the vicinity.
Many submersibles control in-water trim by shifting mercury between chambers at either end of the vehicle. Mercury is also corrosive to aluminum, extremely toxic, requires extraordinary measures to prevent spills, and is difficult to clean up when a spill occurs. The Battelle "tungsten ball trim system" is the replacement trim system for Sea Cliff and Turtle. In this system sintered tungsten balls are the weight medium, stored in two stainless steel tubing coils at either end of the vehicle which are connected by a transfer line. Hydraulic fluid moves the balls through the tubing by means of slip flow past each ball, and plastic balls on either end of the daisy chain of tungsten balls provide a filler in the transfer tube when all the weight is shifted one way or the other.
Both submersibles were initially rated for a depth of 6,500 feet but received upgrades in the early 1980s. While the Turtle was rated at 10,000 foot operating depth, Sea Cliff had her original HY-100 steel crew sphere replaced in 1983 with a titanium sphere capable of 20,000 foot operations. Sea Cliff reached this depth for the first time in March 1985, during a dive in the Middle America Trench off the Pacific coast of Central America. This increase of 1500 meters over Alvin's limits provided access to 37% more of the sea floor. Turtle reached a depth of 10,000 feet on 3 October 1980, and Sea Cliff made it to 20,000 feet on 10 March 1985. At that depth, Sea Cliff was capable of reaching 98 percent of the world’s ocean floor, an area roughly six times that of the surface of the moon. As a result, Sea Cliff enjoyed the distinction of being named flagship for the “Year of the Ocean” in 1985.
Sea Cliff and Turtle were often called upon to locate and recover Navy equipment that was lost at sea. During its 20,000 foot sea trials, Sea Cliff was ordered to the site of a downed Marine Corps Sea Stallion helicopter. Operating at 1,500 feet, Sea Cliff used its manipulators both to retrieve pieces of the aircraft directly and to attach lift lines to other parts. Sections as heavy as 10,000 pounds were recovered. Overall, 61 dives were made, and 80 percent of the aircraft was retrieved. Most importantly, Sea Cliff found and recovered the remains of the aircraft’s four crew members for family burial. Similarly, in 1995, when a Navy swimmer delivery vehicle (SDV) was lost in 814 feet of water off Hawaii, Turtle found and retrieved it in an operation many thought was impossible.
Turtle and Sea Cliff had been based from Navy Landing Ship Dock (LSD), or, more commonly, from Navy oceanographic vessels. Any of them could be transported by C-5 aircraft, although such deployments were uncommon.
Since the end of the Cold War the submersibles Sea Cliff and Turtle were available for limited academic research through a cooperative arrangement between NOAA and the US Navy's Submarine Development Squadron Five in San Diego CA. These vehicles have expanded opportunities for peer-reviewed deep submergence research off the US west coast. Sea Cliff provided the science community with some additional access to the deep sea and permitted observations to depths approaching 6000 meters, a depth range otherwise only available by using ROV Jason or the other tethered vehicles of the National Deep Submergence Facility. This increase of 1500 meters over Alvin's limits provides access to 37% more of the sea floor, which represents an area that is greater than 90% of the surface area presently exposed on the continents.
Following the Navy's decision to decommission Sea Cliff, NAVSEA requested Woods Hole Oceanographic Institution (WHOI) to provide a technical assessment and costing of how to best integrate Sea Cliff into the National Deep Submergence Facility. Perhaps the most serious and biggest impediment to integrating Sea Cliff into the US deep submergence program was the lack of an adequate and stable funding base.
Turtle was retired and loaned to the Mystic Aquarium, Institute for Exploration, where it was placed on permanent display. Sea Cliff was turned over to the Office of Naval Research and as of 1999 was being stored at the Woods Hole Oceanographic Institute while its future was debated
Mystic Aquarium Mystic Ct.