The USS Arleigh Burke (DDG-51), lead ship of her class, has completed her maiden deployment, and the USS Barry (DDG-52), second of the class, is now in the Mediterranean. The John Paul Jones (DDG-53) and the Curtis Wilbur (DDG-54), both recently commissioned, are close behind. Nearly 60 of this class are planned, and they will make up a sizable percentage of the Navy's surface combatant force well into the next century.
It seems an appropriate time to review what has been learned so far about handling the new destroyers. Let's look at a few statistics:
- 504.5 feet long and 66 feet wide—a very wide beam that contributes to excellent sea-keeping and stability in an open seaway
- Large underwater hull and reduced sail area topside—current affects her far more than wind
- Two shafts and four LM2500 gas-turbine engines generating 100,000 shaft horsepower for a top end in excess of 30 knots—fast and responsive with direct pilot-house engine controls
- Controllable, reversible-pitch, five-bladed, 17-foot propellers—with 12 knots the break over between pitch-controlled speed changes (0-12 knots) and RPM-controlled changes (13-30+ knots)
- Draft of 31 feet at 75% fuel and 75% weapons load (around 8,800 tons); at 50% fuel and 100% weapons load (about 9,000 tons), draft of 32 feet
- Highest point, 142 feet above the water—the bridge is a relatively low 50 feet, which provides an 8.2 nautical-mile horizon
The first ship-handling consideration with the class is the size and shape of the hull form, which is quite different from that of the Spruance (DD-963) and Ticonderoga (CG-47)-class hulls. The Arleigh Burkes are shorter (504 versus 567 feet) and much beamier (66 versus 55 feet), with a more pronounced underwater hull and far less topside sail area.
As a result, the Arleigh Burkes are far more affected by current than by wind. The traditional rule of thumb—that a knot of current is equal to 30 knots of wind—is well worth bearing in mind with the new destroyers, which are buffeted by current far more than earlier destroyer variants. It is helpful to think of the ships as having an underwater sail area, and knowledge of current—especially around the piers—is vital. The good news is that the DDG-5Is are far less affected by wind than the Spruances or, particularly, the Ticonderogas.
Another difference worth noting: the new destroyers have outboard-turning propellers—a result of reversing the layout of the Spruance-Ticonderoga propulsion plants—which gives the Arleigh Burkes different characteristics when moving around the pier. The rule still applies that the stern will walk in the direction of propeller movement if the propeller were on the ground—but the ship handler used to inboard-turning shafts must take the difference into account.
Finally, the pivot point is farther aft than in more traditionally constructed destroyers. Rather than just aft of the pilot house, it appears to be located between the stacks. This is a critical point, because it affects every maneuver. It is particularly important at slow speeds, as when mentally calculating turns around the pier. In addition, it makes the ship very difficult to twist when backing down. The Arleigh Burkes will twist reasonably well—although not so smartly as a Spruance or a Ticonderoga when going ahead—but any stem way will virtually kill a twist as the pivot point moves aft and the engines lose leverage over the hull.
The ships are wonderful at sea, where their low, beamy form gives them superb sea-keeping ability. Very stable in rough seas, they are generally affected only by quartering seas that work their way under the pivot point and give the ship a pitching motion. The best illustration of their sea-keeping abilities is that at full speed, with full rudder, the ships heel only 8°-10°.
During underway replenishment, the large, full-bodied characteristics of the hull intensify suction effects when coming alongside another wide-body oiler. It is prudent to come in a bit wider than was done with older destroyers or cruisers, perhaps 140 feet, and then work in to 120 feet while putting over rigs. The good news is that the heavy hull makes for a fairly smooth ride alongside, with less effect from the oiler.
Underway replenishment gear includes a retractable forward kingpost with a sliding pad eye, as well as two sliding pad eyes located port and starboard between the stacks amidships. There are four fueling-at-sea stations, two port and two starboard. The forward stations are located on a small platform just below the bridge wings and are clearly visible for the conning officer—a real benefit. The after stations, where JP-5 aviation fuel comes aboard, are also easily visible.
Visibility for the ship handler is excellent, with a clear view of the stern, including an athwartship view almost to the opposite corner of the fantail. It also is easy to see the entire strake of the ship for approaches on the pier or the oiler. The only visibility drawback is the large Phalanx close-in weapon system mount directly in front of the center of the bridge; although there is ample visibility around the mount, it can be somewhat distracting.
The ships draw slightly less than the Spruance or the Ticonderoga class—32 feet is the maximum and charts are generally laid out with anything less than 36 feet as potential shoal water. Layout of the bridge is excellent, with the navigation and chart table on the same side of the bridge as the captain's chair, reducing the cross-bridge noise and confusion. A WRN-6 Global Positioning System and dual WSN-5 inertial navigation systems, with all normal backup systems, provide accurate plot information to the officer of the deck and the conning officer.
The ships have a main, centerline stockless anchor weighing 9,000 pounds with 12 shots of chain (180 fathoms or 1,080 feet); arid a lighter, port side anchor weighing 4,000 pounds with 9 shots of chain (120 fathoms or 720 feet). Anchoring is fairly straightforward, although the ships lack a second wildcat-windlass on the forecastle, and employ a system that cross connects the second, lighter port anchor to the windlass. This makes Mediterranean mooring a particular challenge.
The ship rides comfortably on the main, centerline anchor, which—in 40 fathoms—is rated to hold in up to 70 knots of wind and four knots of current. Maneuvering for an anchorage is easy. Reduce speed to five knots about 500 yards from the drop point, and come to all stop with 275 yards to go. Hit a back one-third bell as the ship comes to a stop and drop the anchor as soon as stern way is apparent. Veer three-fourths of the chain with 25% astern pitch, and then set the anchor with a good one-third backing bell. Conclude by veering the remaining chain.
From an engineering perspective, the destroyers are quick and responsive, much like the DD-963 and CG-47. With 100,000 shaft horsepower, the Arleigh Burkes need their extra power (20,000 more than the DD-963 or CG-47) to overcome increased underwater hull drag, and end up with roughly the same maximum speed—more than 30 knots. The ships' three gas turbine generators produce 2,500 kilowatts each.
The destroyers have dual rudders and excellent acceleration and deceleration. They will accelerate from all stop to ahead flank in less than 90 seconds. Using a back-full bell, they can stop from ahead full to dead in the water, in about a minute while covering less than 600 yards.
The steering system has several levels of control, with information generally running from the helm to the steering units on a data bus. The modes include computer-assisted auto pilot; computer-assisted manual, which is the normal mode of operation; and a backup manual path that bypasses the data bus for complete safety.
When performing divisional tactics, the ships do very well in column and line abreast formations with larger U.S. Navy cruiser- and destroyer-size ships because they have roughly the same acceleration and deceleration as other gas turbine ships. They are less nimble than small allied frigates, and greater care must be taken when maneuvering with them in closely spaced (500 yards) formations.
The ships use six standard mooring lines, and the new Kevlar lines seem to have sufficient holding power. Around the pier, the ships are somewhat heavy and harder to maneuver than the Spruances and the Ticonderogas; it is preferable to have two tugs for mooring—one is a bare minimum—given the large and sensitive SQS-53C sonar dome located forward under the center of the forecastle. Tugs should be made up opposite the gun mount on the bow and along the after missile deck (rather than the fantail) astern.
When making an approach to a pier, it is best to move the ship toward the pier at a steady five knots, unless a heavy current is running, in which case higher speed may be necessary to maintain heading. In close, slow by reducing pitch to about 25%t until the bow is close enough to get lines over. Use the forward tug to control the bow, and twist the stern in using opposed engines and a full rudder.
Getting underway from the pier is done essentially in reverse: pull the bow off with a tug while twisting the stern. This will walk the ship sideways nicely until there is sufficient room to back out using about 25% pitch, increasing to a back one-third bell. Naturally, be careful when using a one-third bell while tugs are attached, especially given the heavy hull.
In general, the ships turn well except when backing. To change direction going astern, it is far more effective to cast the ship than to twist her.
Following are a few good points to bear in mind concerning turn diameters:
Fuel economy is fairly standard for the four-engine LM2500 plant. Trail shaft operations—one engine on one shaft—are by far the most economical way to run the plant. The most economical combination, i.e., gallons per mile, is trail shaft at around 14 knots; the most economical split-plant configuration—one engine on each of two shafts—is at 15 knots. At full plant—two engines on each of two shafts—17 knots is the most economical speed.
For man-overboard situations, the best approach is a simple Anderson turn, using full or hard rudder first and then tightening the turn by stopping the inboard shaft about two-thirds of the way around the circle. Alternately, a Williamson turn can be used at night, shifting the rudder at about 60° beyond the steered course. Naturally when the tail is out, a racetrack turn should be used for tail safety.
Overall, the Arleigh Burkes are superb sea-keepers, very stable and safe with an excellent engineering plant and highly accurate navigation suite. They are well powered in the open sea and for underway replenishments and division tactics. While challenging to handle around the pier and in constrained waters, the class is maneuverable enough to keep the sensitive sonar dome off the pier and overcome the dramatic effect of current on the hull. They are solid, well built destroyers—and a pleasure to drive.
