The Arleigh Burke (DDG-51)-class destroyers soon will become the largest ship class in active service. Little has been written about their distinctive shiphandling characteristics, however, since then-Commander James Stavridis's definitive "Handling the Arleigh Burkes" in the October 1994 Proceedings (pp. 66-68). The article remains a terrific primer and a must read for DDG-51 drivers. This sequel is a supplement.
Environmental conditions in many U.S. homeports-most notably strong tidal cur rents- prevent officers from freely experimenting with their ships' handling characteristics. The result sometimes is a reliance on tugs to the exclusion of the ship's fine points of maneuvering. Conditions in many places in the Caribbean, Mediterranean, and Persian Gulf, on the other hand, favor more independent ship control. In fact, many ports lack adequate tug power and control
Putting a traditional even twist on the ship from a standstill will result in sternway. To twist effectively, the ship must either have some headway on at the start, or be overpowered on the outboard engine with an uneven twist. To twist to starboard from a standstill, for example, requires a two-thirds ahead bell on the port shaft and a one-third backing bell on the starboard shaft with full rudder. Throttling the outboard engine (port in this case)—between 2/3 and 1/3 controls headway.
The backing effect of a twist is advantageous when backing onto a pier. Throttling the outboard engine while twisting controls sternway in this case, while simultaneously lifting the stern (in light currents). With a stiff current, the DDG-51 will not lift astern and an aft tug should be considered.
Fine adjustments to bow movements may be made when forced to approach a pier landing without a reliable forward tug, or with a tug that is only configured to pull. Using one shaft at slow speeds (20% to 30% pitch) allows the outboard turning screw to walk and moves the bow in the opposite direction very slowly. Full rudder in either direction allows for more precise control of the bow's rate of movement. To move the bow to port, for example, slowly, apply 30% pitch to the starboard shaft with left full rudder. Swing then can be checked by any combination of: stopping the starboard shaft; shifting the rudder; stopping the starboard shaft and applying 30% pitch to the port shaft; or, backing either shaft. Once the bow is in position, lines can be used to hold the bow while small bell and large rudder orders bring the stern in slowly.
Use of hard-vice full-rudder makes a positive difference in close quarters, slow speed maneuvering situations. The outboard-turning screws and inset position of the rudders make the difference less pronounced than with a Spruance (DD-963) or Ticonderoga (CG-47); it is substantial enough, however, to be used routinely for maximum response.
Many ships choose to ignore the Mark 2 lightweight (4,000 pounds) Danforth port anchor in favor of the heavier (9,000 pound) centerline Navy stockless anchor- in the mistaken belief that bigger is better. Both are rated evenly to hold in 70 knots of wind and 4 knots of current at 40 fathoms. The port anchor has a rated holding strength of 75,076 pounds in sand: this is greater than the centerline anchor's 63,900 pounds. The lightweight Danforth is ideally suited for many sand anchorages, and the reconfiguration of the single wildcat to the port anchor rates consideration. The port anchor does have a significant disadvantage: its reluctance to freefall, even from a dipped starting position. Consequently, the centerline anchor is the only choice as a ready anchor in an emergency anchorage scenario.
Anchoring in more than one knot of current requires a more aggressive approach to the anchor drop point. The traditional method of slowing to five knots at 500 yards before stepping speed down to zero over the anchorage is not effective in Arleigh Burkes. Current impacts the ship's considerable underwater hull form and foils the deceleration to final positioning. To prevent this, maintain five knots through the water until 150 to 200 yards from the anchorage, then order all back 1/3. The ship will confidently coast over the anchorage just as sternway begins to take effect, thereby allowing more precise release of the anchor. Sternway then may be adjusted with one or both shafts as the chain is veered to desired scope. Global Positioning System accuracy enhances the crew's awareness of the true position of the anchorage and should be incorporated into any anchoring scenario, regardless of visual references available.
Deceleration from a 20-knot underway replenishment (UnRep) approach to a 13- knot ROMEO speed holds steady at roughly 60 feet per knot. By matching the oiler's speed against own-ship's revolutions-per-minute (RPM) order while waiting astern, one can determine the true (and final) ROMEO speed RPM before commencing the approach. Applying the 60 feet per knot calculation allows the exact alongside RPM to be ordered from the 20-knot approach, resulting in the pre-determined final line-up position alongside. The ship will ride effortlessly between the fore and aft pressure zones, requiring only small course adjustments to control separation and thus facilitating a "no-bell" UnRep.
The pitch-control breakover point-where either RPM, or the combination of pitch and RPM, determines speed-is different from the 13-knot breakpoint inherent in a Spruance and Ticonderoga. In fact, the breakover occurs at different speeds based on ordered plant line-up. At full plant, the break over occurs between 9 and I 0 knots; at split plant between 7 and 8 knots; and at trail shaft between 6 and 7 knots.
Creating a lee for small boats can be done easily in many sea states. In addition to putting the port side to the wind/sea, the rudder can be positioned right full with 30% pitch on one or both shafts. The result of this combination is a slow and lazy turn that provides a generous lee.
The Arleigh Burke offers distinct shiphandling challenges. Experimenting and reinforcing an appreciation of the ship's characteristics will go a long way in increasing the DDG-51 sailors' shiphandling confidence in new maneuvering situations. Stavridis's bottom line remains unchanged, "They are solid, well built destroyers-and a pleasure to drive."