JOHNSON SEA LINK 



LENGTH: 23 ft 



BEAM: 7.9 ft 



HEIGHT: 10.8 ft 



DRAFT: 7.1 ft 



WEIGHT(DRY): 9.5 tons 



OPERATING DEPTH: 1,000 ft 



COLLAPSE DEPTH: DIVER 6,000 ft 



PILOT 6,000 ft 

 LAUNCH DATE: 1971 



HATCH DIAMETER: 24 in. 



LIFE SUPPORT (MAX): 72 man-hr 



TOTAL POWER: 32 kWh 



SPEED (KNOTS): CRUISE 0.75 



MAX 1.75 



CREW: PILOTS 1 



OBSERVERS 3 



PAYLOAD: 1,100 lb 



PRESSURE HULL: Two hulls: Forward spherical hull is for pilot and observer and is composed of acrylic plastic (Plexiglas grade G) 66-in. OD, 4 



in. thicic and weighing 2,300 lb. The after hull is a cylinder of aluminum (alloy 5456) 50.5-in. OD, 3.36 in. thick and Sl^/s in. long with aluminum 



(alloy 5456-0) plate hemispherical endcaps 2.33 in. thick at the apex and 2.80 in. thick at the equator. The entire cylinder is 8 ft long and weighs 



4,800 lb. One metal hatch is topside of the sphere and the second hatch is on the bottom of the cylinder for diver lock-out. 



BALLAST/BUOYANCY: Surface flotation is from two port/starboard tanks which provide positive buoyancy of 1 ,940 lb; these tanks are flooded to 



dive and blown with compressed air on the surface. Fine buoyancy trim control submerged is obtained from two tanks located (1 ea.) within the 



surface flotation tanks; they are blown by compressed air and contribute ±170 lb of buoyancy. To compensate for weight of divers and their 



equipment when they leave the cylinder are two aluminum tubes (±180 lb ea.) (which are a part of the top two frame members) and bilge ballast 



tanks (±1 10 lb ea.) located in the bottom of the divers' compartment. 



PROPULSION/CONTROL; Propulsion is attained through eight reversible 28 VDC electric motors driving 14-in., three-bladed propellers. 



Forward/reverse propulsion is from three stern-mounted (trainable 90° left and right) and two port/starboard motors mounted amidships. Vertical 



propulsion is from one each, fore and aft thrusters. and lateral propulsion is from a forward-mounted thruster. 



TRIM: No systems available. 



POWER SOURCE: All power is obtained from fourteen 2-VDC, lead-acid batteries located in a pressure-resistant battery pod (jettisonable) attached 



to the bottom of the submersible. The batteries are aligned in two banks; each supplying 14 VDC. 



LIFE SUPPORT: O2 is from two cylinders (2,640 psi at 330 SCF ea.) mounted externally. The starboard tank supplies the sphere and the port tank 



the cylinder. He for the diver's cylinder is supplied from a sphere (1,750 SCF) and four reserve buoyancy tanks (502 SCF). To remove CO2 both 



sphere and cylinder carry 8 lb of Baralyme through which fans force compartment air. 



VIEWING: Panoramic viewing through plastic forward sphere. Three viewports in the aft aluminum cylinder, one is central on the forward endcap 



and one each (port/starboard) on the cylinder. All viewports are double acting, the outside port is 7-in. ID, 9.5-in. OD and 1 in. thick. The inside 



viewport is 10.25-in. OD; 7-in. I D and 2 in. thick. Two additional viewports are located in the double-acting diver's egress hatch. 



OPERATING/SCIENTIFIC EQUIPMENT: UQC, Doppler sonar navigation system, CTFM sonar, transponder, pinger, echo sounder, compass. 



Diver-to-submersible, sphere-to-cylinder communication system. 



MANIPULATORS: None. 



SAFETY FEATURES: Scott-type breathing masks in both sphere and cylinder are connected to high pressure air system. Battery pod (1.5 tons) 



jettisonable. Surfacing can be controlled from diver's compartment. Divers and pilot/observer may lock-out in an emergency. Both surface flotation 



and ballast/trim tanks can be blown at operational depth ( 1,000 ft). 



SURFACE SUPPORT: R/V JOHNSON with articulated crane. 



OWNER: Owned by the Smithsonian Institution, Wash., DC. Operated by the Marine Sciences Center, Ft. Pierce, Fla. 



BUILDER: Designed by Mr. Edwin Link, built by Aluminum Co. of America (ALCOA). 



REMARKS: Operational. A second vehicle is due for completion in 1974. 



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