15 



The first TROV (Tethered Remotely Operated Vehicle) was constructed in 1976 

 for the Canadian National Water Resources Institute (then Canadian Center for 

 Inland Waters) and was battery operated. The later models, beginning in 1976 

 with TROV 01, are powered from the surface. By March 1979 eight TROVs will 

 have been constructed. The first prototype TREC (Tethered Remote Camera) 

 was built in 1976; two years later seven production-line vehicles were 

 produced. Six were sold by the end of 1978. 



The TREC vehicle (Plate 2. 2) provides many of the capabilities offered by the 

 RCV-225. The vehicle is more typical of the field at large, in that it is 

 rectangular- shaped and composed of an open-aluminum framework which encloses 

 and supports all components. Atop the framework is a block of syntactic 

 foam which provides positive buoyancy. The vehicle occupies 0.9m-^ (34.6 ft-^) 

 relative to the RCV-225' s 0.2m3 (6 ft^) and is 77kg (170 lbs) heavier. The 

 complete system consists of a control/display console, umbilical cable and 

 the vehicle itself. TREC's maximum depth is limited to 366m (1,200 ft). 

 Unlike Hydro Product's vehicle, the TREC system does not employ a launcher. 



TREC's control/display console includes propulsion, light intensity, camera 

 focus, tilt, manipulator control, TV and video recorder controls, TV display, 

 depth and altitude. A manipulator may be fitted which provides three motions: 

 up /down, in/out, open/shut (claw) . An off-the-shelf Panasonic low light 

 level TV camera provides remote viewing, and four, 1 hp thrusters produce yaw, 

 thrust and heave vehicle motions. Navigation can be provided by a magnetic 

 compass or gyrocompass or through one of the commercially- available acoustic 

 tracking systems. 



There is no objective in this report to assess or compare one ROV to another. 

 It is still too early to determine which of the numerous vehicles is "best". 

 The ISE vehicles offer certain advantages over the Hydro Products vehicles 

 and vice versa. Indeed, a general purpose ROV that can perform every task with 

 100 percent efficiency is as unlikely as is a general purpose manned submersible. 

 As operational experience accumulates, and is fed back to the manufacturers, 

 each subsequent vehicle becomes more reliable and efficient in its operation. 

 Initially there was some question as to the need for a launcher or clump 

 within/and from which, the vehicle was deployed. Now it has become clearer - 

 although not fully accepted - that a launcher is desirable during platform 

 inspections because it performs the task of keeping the greater part of the 

 tether cable taut and outside of the platform to avoid entanglement, while 

 the vehicle itself operates on a relatively short umbilical and generally 

 in the horizontal plane while within the structure. The non- launcher vehicles 

 have gained greater - although not universal - acceptance in tasks where the 

 vehicle operates underway in such work as pipeline inspection where the 

 support vessel maintains station above the vehicle as it progresses (a function 

 termed "live boating") . 



The statistics used in the following discussion do not include an ROV 

 designated PAP 104. The Societie Eca, Meudon, France has produced and sold 

 over 128 PAP 104s to various NATO Navies. Since this number is almost more than 

 has been produced by the entire' field, including PAP- 104 in the discussion would 

 not produce a representative assessment. The vehicles are designed specifically 



