28 



indicates that 68 percent operate in less than l,000in (3,280 ft) depth. 

 The peak at 2,023m (6,600 ft) reflects the 26 RCV-225s constructed. Significantly, 

 while the RCV-225 vehicles themselves can reach 2,000m depth, as of September 

 1978 no operating vehicle had a cable longer than 400m (1,312 ft). 



2.1.6 Speed 



Vehicle speed at maximum operating depth ranges from 0.5 to 4 knots, the 

 average is 1.6 knots. These same values represent the bottom currents in 

 which the vehicles can operate at their maximum operational depth. Speed 

 in itself is not an important factor, since all work is conducted at very low 

 speed, instead, it is the ability to stay on the job and maneuver in the presence 

 of fast currents that is significant. 



2.1.7 Instrumentation 



A matrix of vehicles and their data-gathering instrumentation is presented 



in Table 2.3. In view of the dynamics of this field it is likely that the 



data in Table 2. 3 will be out of date almost by the time it is published, and the 



reader is therefore cautioned to use this data as a guide, rather than a 



conclusive tabulation. Several operators have instrument development programs 



now underway which will add to this list by the spring of 1979. To the 



extent possible, these future developments are discussed in a later chapter 



of this report. 



2. 1.7. a Television 



The heart of an ROV system is its closed circuit television. All vehicles 

 have CCTV, the following manufacturer's TV systems are employed: 



Hydro Products (TC-125 and TC-125-SIT) 



Panasonic (low light level) 



Marine Unit Technology Ltd. (SIT and vidicon) 



Rebikoff Underwater Products (DR630) 



Sub Sea Systems (CMS) 



CSF Thompson (low light level silicium) 



Rees (181 low light level) 



RCA (TC 100) 



EMI (England) 



Winn Technology Ltd. (low light level) 



Hydro Products and Panasonic are the two most frequently used television 

 systems. 



Only MURS-100 and 300, and SEA INSPECTOR use color TV, all other vehicles 

 employ black and white. Line resolution is nominally 525 to 550, but reportedly 

 can reach 700 at the center of the screen. Viev/ing distance varies according 

 to water clarity, 7 to 10m (23 to 33 ft) is generally accepted. Low light 

 level television cameras are used almost as frequently as the standard vidicon 

 tubes. 



The majority of ROVs have one television camera which is either fixed in its 

 viewing position (and relies upon the vehicle's manueverability for re-positioning) 



