UNDERWAY REPLENISHMENT NWP 4-01.4 - Historic Naval Ships ...

NWP 4-01.4position and remains extended while the highline ispassed. The highline winch operator pays out wirethrough the ram until the highline reaches the receivingstation (see Figure 6-4). Ensure that the highline ASDis in the ON position, so that slack wire is pulled to preventfouling on the highline winch drum.UPPER SHEAVESHIGHLINERAM(PISTON)CYLINDERHYDFLUIDLOWER SHEAVESHIGH PRESSURE(H.P.) AIR SUPPLYACCUMULATORH.P. AIRFLOATINGPISTONHYD FLUID6.6.1.2 Tensioning the Highline. When the highlineis connected at the receiving station, the highlinewinch operator takes in wire and compresses the ram toabout midstroke. The highline ASD should be turnedOFF. Tension is set in the highline as soon as the ramstarts compressing. The predetermined ram pressureprovides the amount of tension in the highline.6.6.1.3 Operating the Highline. Once the ram isdepressed to midstroke, the highline will haul in withany upward movement of the ram and pay out with anydownward movement of the ram. This action compensatesfor normal ship motion. The ram compresses topay out wire when the ships move apart and extends tohaul in wire when the ships move closer together. Thehighline winch operator hauls in or pays out wire onlyto keep the ram within the safety zone.The amount of tension in the highline can be variedto suit (1) the static-tested load of the padeye at the receivingstation and (2) the weight of the load to betransferred. Increasing or decreasing the weight of theload on the trolley will increase or decrease thehighline’s catenary, but will not change the tension inthe highline.NoteBe sure that the air pressure and volume arein accordance with operating instructions.Ensure ram operating air valves are fullyopen. Partially closed valves will causerelief valve to lift.The amount of tension in the highline depends on thepressure of the air in the ram tensioner’s accumulator.For every 100 psi (689 kPa) of air, there is about 1,000lb (454 kg) of tension in the highline. For example,1,950 psi (13,443 kPa) of air will put about 19,500 lb(8,845 kg) of tension in the highline.6.6.2 Inhaul and Outhaul Winches. The inhauland outhaul winches at the delivery station move thetrolley and suspended load along the tensioned highlineFigure 6-3. Ram Tensioner (Cross-Section)6-9 ORIGINAL