Parameter 



Characteri sties 



Speed 



Maximum: 1.8 knots without fairing 





5 knots with fairing 





Minimum: knot 



Duration 



1.3 hr using present lead-acid batteries 





4.4 hr using lithium battery now under 





construction 



Turn radius 



ID ft (approximate) 



Load capacity 



25 lb/ft of extension 



Launching platform 



Existing platforms 



Maximum depth 



2200 ft 



Autonomous functions 



Preprogrammed trajectory execution 





Pipeline-following capabil ity 





Automatic response to emergency sensors 



Table 4. Summary of NOSC/USGS Free-Swimming 



Vehicle's Performance Characteristics. 



SUBSYSTEM BREAKDOWN 



A brief functional breakdown describing some details of existing and 

 planned capabilities will now be given. All subsystems are part of the tech- 

 nologies being investigated for potential use with unmanned, untethered sub- 

 mersibles (figure 2). Other aspects of these technologies, such as acoustic 

 communication and bottom transponder navigation, are being investigated by the 

 University of New Hampshire and will be tested or demonstrated on their EAVE 

 EAST submersible (see reference 7). 



Communication Subsystem 



For entirely autonomous operation before launch, the communication link 

 to the EAVE WEST vehicle is simply an umbilical cable which is disconnected 

 after preprogramming the submersible and transferring the resulting data base 

 to the vehicle. The umbilical cable is disconnected while the vehicle is 

 executing a preprogrammed time delay. 



The use of fiber optics as a communication link to this submersible is 

 being investigated. This link is an attempt to fulfill the real-time console 

 communication requirements through an extremely small, lightweight, low-drag, 

 single fiber-optic strand. This fishing-line-size cable will be able to 

 handle all data and control requirements of the entire vehicle at the full 

 bandwidth of existing visual data sensors. If this is achieved, it will be 



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