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

NWP 4-01.4COURSE TO PERMIT FLIGHTOPERATIONSWIND AND SEAPOSSIBLE COURSE INMODERATE OR HEAVY SEASSHIPS'COURSEWIND AND SEASHIPS'COURSEFigure 2-1. Replenishment Course2.2.2.3 Course Selection — Wind Conditions.Wind conditions are not as significant as sea state, butmust be considered when selecting the replenishmentcourse.1. Relative wind velocity should be as low as thetactical situation permits. High relative winds,especially in cold and rainy weather, willquickly fatigue exposed personnel and increasereplenishment time. Therefore, a downwindheading may be preferable.2. Under other conditions, heading into the windmay be more desirable. It may permit carriers toconduct flight operations at replenishmentcourse and speed (Figure 2-1). Also, steamingwith the wind one or two points on the port bowprovides a lee for small units replenishing tostarboard of larger units.3. For VERTREP, the relative wind should be between330° and 030° on the bow (see Chapter 9).Relative wind direction does not inhibit anH-46 helicopter. Receiving ships can maneuverduring VERTREP with an H-46, provided it isdone with the helicopter pilot’s concurrence.4. Small units with large deckhouses aft tend toyaw badly with winds above 30 knots from abaftthe beam.2.2.2.4 Speed Selection. Speeds between 12 and16 knots are usually advisable. However, weather conditionsinfluence the selection of a replenishmentspeed, just as they do the selection of a replenishmentcourse. Under all conditions, a ship must make sufficientspeed to maintain steering control. A speed lessthan 8 knots is not advisable, because of reduced ruddereffect. A speed above 16 knots may be used, if weatherpermits; but greater lateral separation must be maintained,because of the increased venturi effect.NoteCG 47, DDG 993, DD 963, FFG 7, and LSD41/49 Class ships are equipped with controllablepitch systems, which control speed in themodulate transmission mode (MTM) (speedvaried by pitch changes) before achieving 100-percent pitch and in the modulate enginemode (MEM) (speed varied by RPM changes)after achieving 100-percent pitch. CG 47s,DDG 993s, and DD 963s reach 100-percentpitch in the 11.0 to 11.6 knot range; LSD41s/49s in the 8.5 to 9.5 knot range; and FFG7s at 10 knots. While this does not present anyship-handling restrictions while alongside, itshould be noted that speed response is faster inMEM than in MTM; generally, a replenishmentspeed above the 100-percent pitch pointis preferred.2-4 ORIGINAL