Page 220 - The ROV Manual - A User Guide for Remotely Operated Vehicles 2nd edition

8.8 Underwater cable design 209
FIGURE 8.52
Open-End Spelter socket.
The thermoset jackets are readily bonded to in secondary operations to add underwater connec- tor terminations.
Another cable seeing increasing use in moderate depths is the AWM20233. Billed as a “Low Capacitance Communications/Instrumentation Cable,” the outer jacket is polyurethane extruded over a copper braid shield. Inside are individual twisted pairs wrapped in aluminum/polyester foil with a stranded, tinned copper drain wire. Nylon rip cord filler provides cross-sectional bulk. End- users report success for yearlong durations at 2.5 miles (4 km).
Additional cable options may be known by your connector manufacturer. Ask their opinion, but use your own best judgment.
8.8.13 EM terminations and breakouts
Mechanical strength terminations are used to transition force from the winch to the umbilical and the umbilical to the TMS or to the tether of an ROV.
The termination type can influence the break strength of the cable. It is important to use similar terminations on each end of the cable. Do not rely on locking sleeves for transferring the load off a cable.
Two common field installable mechanical end-fitting/terminations are as follows:
• Spelter socket
• Kellems grip
8.8.13.1 Socket or spelter socket
A socket or spelter socket uses molten zinc or epoxy poured in a socket to bond the splayed cable to the fitting (Figures 8.528.54). The spelter socket is suitable for steel strength members with
(Courtesy Crosby Group.)