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Propeller Boss Cap Fins (continued) peller open water model tests have shown gains in efficiency of 3 per- cent to 7 percent and resistance/ self-propulsion tests conducted on a 6-meter model indicated gains of 2 percent to 5 percent. A graphical summary of the model tests are shown in Fig. 1. Speed trials conducted in Sep- tember 1987 for the Mercury Ace, a 44,979-grt car carrier of Mitsui OSK Lines Ltd., fitted with PBCF, demonstrated a real ship efficiency improvement of 4 percent. Trials were conducted simultaneously with a like sister ship without PBCF. Fig. 2 shows the graphical results of these trials. On-ship trials have also shown that installation of PBCF has no effect on maneuverability. As PBCF controls the flow behind the propeller—it has little depen- dence on the hull form like other energy-saving devices. As a result, PBCF is effective on ships of any type. PCBF is said to be especially effective for high-speed ships with a high propeller pitch ratio. Smaller and lighter than conven- tional energy-saving devices set around the propeller, PBCF can mi GROUP FINCAMERI IS SHEPREPADRS AND CONVERSIONS YARDS FOR SHIPREPAIRS AND CONVERSIONS: • TRIESTE (A.T.S.M.) - Tel. (0) 40 7391 Tlx 460122 FINCAT I • VENEZLA (C.N.O.M.V.) - Tel. (0) 41 798511 Tlx 410255 FINCVE I • TARANTO - Tel. (0) 99 407134 Tlx 860020 FINCTA I • PALERMO - Tel. (0) 91 545288 Tlx 910041 FINCPA I • NAPOLI (S.E.B.M.) - Tel (0) 81 7858111 Tlx 710040 FINCNA I • GENOVA (O.A.R.N.) - Tel (0) 10 59951 Tlx 270090 FINCOR I • GENOVA WORKS (M.G.N.) - Tel. (0) 59951 Tlx 270370 FINCMG I • LIVORNO - Tel. (0) 586 882121 Tlx 500071 FINCLII Shiprepairing Division Genova/Italy via Cipro 11 tel (0) 10 59951 fax (0) 10 5995379 tlx 270168 FINCGE I 20 graving docks for ships up to 400,000 tdw, 8 floating docks for ships up to 160,000 tdw 13 km of repair berths and the frontage of seven repair yards around the Italian coastline: the resources of Fincantieri's Shiprepairing Division are conveniently situated along the main and busiest Mediterranean shipping routes. The repair yards facilities and back-up resources are organized and equipped to cope with any shiprepair or ship conversion. Large or small merchant vessels and naval ships, offshore units and marine steam and diesel engines are repaired, modified or converted by the newest, most advanced techniques, developed over many years, to restore or improve performance. The Shiprepairing Division is also established in constructing offshore units to highest technological standards. (ZFinCAnTIGRI Cantieri Navali Italiani S.p.A. Circle 128 on Reader Service Card Figure 2 also be manufactured at low cost. The investment can be recovered in as little as one year. An important feature is that in- stallation of PBCF can be per- formed in a very short period of time for a new ship under construc- tion or a ship in operation. Installa- tion simply requires the removal and replacement of the propeller boss cap with PBCF. With a ship in drydock, this can be accomplished in only four to five hours. The added weight also has an insignificant ef- fect on shaft alignment and bearing loads. PBCF has the same number of fins at- tached to the boss cap as that of the ship's propeller. Installation simply re- quires the removal and replacement of the propeller boss cap with PBCF. Since January of this year, PBCF has been fitted on over 23 ships of several types. All are said to have experienced significant increases in propulsion efficiency ranging from 3.2 percent to 6.7 percent. The aver- age increase in efficiency has been 4.2 percent For more information and a copy of the technical paper on the devel- opment of PBCF, Circle 8 on Reader Service Card AWO Reelects Knight Chairman Of The Board The American Waterways Opera- tors, an Arlington, Va.-based trade association, recently announced that Arthur M. Knight, executive director of Reinauer Industries of Newark, N.J., has been reelected chairman of the board of directors. 62 Maritime Reporter/Engineering News
