Page 28: of Marine Technology Magazine (October 2012)

Ocean Observation: Gliders, buoys & sub surface monitoring networks

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O shore Systems TE Connectivity, represent an opportunity to reduce the size and weight of control, communication, and instrumentation cables?while offering the same or better electrical and me- chanical performance than conventional cables. Consider that the cabling on an offshore platform can run to several tonnes. Lightweight cables can save 25% to 30% in a typical applica- tion. What?s more, their diameter is reduced by 30% to 40%, freeing up valuable space on the platform. The space and weight reductions of the cable mean addition-al savings in the cabling infrastructure. Cable trays and other supports can be smaller and lighter. The same holds true for the glands. Tighter bend radii are also a bene t of a reduced-diameter cable, which can simplify pathways and the installa- tion and routing of cable.With more than 475 km of cabling on a typical large offshore platform, lightweight, thin-wall cable offers potential savings of up to 105 tonnes topside. The total cabling system ? includ- ing smaller cable glands, trays and transits, can lead to overall weight savings of approximately 165 tonnes and cost savings in excess of 15%. Smaller, lighter cables are of limited bene t if they offer re- duced performance. In the demanding environment of an off- shore platform, cables must offer:  Mechanical robustness to resist abrasion  Environmental toughness to resist temperatures, seawater, oil, solvents, and petroleum mud  Safety, which includes low toxicity, low ß ammabil- ity, and circuit continuity in the event of a Þ reThe key to these size and weight reductions is the use of a unique thin-wall insulation used on the conductors. A typi- cal cable used topside meets the requirements of EN60092 and has an insulation wall thickness of 0.8 mm. Thin-wall in- sulation, on the other hand, meets the same performance re-quirements while reducing the thickness to a mere 0.2 to 0.3 mm. The only difference between the traditional cable and the lightweight cable in Figure 2 is the type and thickness of the insulation. The size reduction of thin-wall insulation is dra- matically apparent.Figure 3 illustrates the cascading effects of the size reduc- tion of a single cable by showing multiple cables in a tray. Reductions of 40% are routine?with the bene ts of smaller pathways, lighter-gauge cable trays, and smaller glands and feed-throughs. In retro t or upgrade applications, thin-wall cables allow more cables in the same existing space. As plat- Fig. 1. As offshore platforms be- come more sophisticat-ed, the need for efÞ cient use of space increases.28 MTROctober 2012MTR #8 (18-33).indd 28MTR #8 (18-33).indd 2810/3/2012 9:47:09 AM10/3/2012 9:47:09 AM

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