Having served in five cruisers, I like to imagine that, while not an artist by any means, I have developed a facility for handling these ships. Being a commanding officer (CO) certainly has compelled me to get much better at it than I was before. In an age when most first-- tour division officers are sent to different ship classes soon after they qualify as officers of the deck, and second-tour officers come from widely varied hulls, if a cruiser's skipper is not the expert, he is the closest thing to it. Given the force of necessity and the experience of watching some of my old-Navy COs do the job, I want to open for discussion some of the things I have learned about driving an Aegis cruiser.
Pump the Rudder
The Ticonderoga (CG-47)-class cruisers have the same hulls as Spruance (DD-963)-class destroyers. They are graced with extraordinary power and cursed with short rudders that extend only to the center of each screw's hub. I had never heard of "pumping a rudder" until shortly before I assumed command. On my first two Aegis cruisers, the technique simply was not known. This is unfortunate because it is a powerful and unique tool that allows for a dramatic increase in the rate of turn, while creating little, if any, increase in forward speed.
Flow of water across the rudders makes a ship turn. The more flow, the faster the rate of turn. So, what is to be done at low speeds, when speed is to be avoided—for example, close to the pier—and the cruiser turns with a sluggishness that is little more than wallowing? The answer is a sudden, powerful burst of water flow over the rudders that is metered in such a way as to prevent an increase in speed over the ground. It can be accomplished by going from a stately ahead one-third bell (engine speed) to an ahead-standard bell. The increase in bell, however, is held only until you hear the engines whine from the bridge wing, which will tell you the burst is accomplished and you should return immediately to the lower speed. The net result is an enormous pulse of water on the rudders but a negligible increase in speed.
Pumping the rudder might be the only way a turn can be made without tugs. For example, a cruiser entering Naval Station, Pascagoula, Mississippi, needs two tugs. A turn near the end of the navigation detail is almost 90 and desperately narrow. Moreover, as it lies in an area where several rivers play in the unpredictable generation of current, the cruiser's slow rate of turn at the five-knot "speed limit" can render the ship a helpless victim of wind and water. Under normal circumstances, it is virtually impossible to make the turn without the hard push of tugs.
Because I wanted to test the effectiveness of pumping the rudder, I instructed the pilot to position the tugs but not to push unless so directed. Then we pumped the rudder repeatedly from one-third to standard bells as the ship turned. (Between each pump, it is essential that the ship's speed be allowed to diminish to less than five knots. You must avoid a steady building of speed, which, among other things, renders tugs useless in the event they are needed.) By pumping, we demonstrated that, in anything other than the most severe conditions of wind and current, the turn was possible without tugs.
Drag the Shaft
The Aegis cruiser backs in a twist. Ahead one-third, back one-third; ahead two-thirds back two-thirds—it does not matter. The ship will start an accelerating backward twist, a problem aggravated by the fact that cruisers twist poorly and slowly. Technically, dramatic twists exceed torque limitations and still are not sufficiently effective. Unless you have an absolute requirement to twist in place, a much more effective turn—with less advance than a pumped rudder—can be attained by dragging a shaft. By combining a twist with a small forward or aft speed, the ship can achieve a greater rate of turn than can be had in a regular twist. This also produces a turn with less advance over ground than that attained by pumping the rudder. The ship moves slowly ahead (or astern) and turns very tightly.
For example, imagine that starboard side to, bow out, you wish to make a 90 deg turn to starboard once you are away from the pier. Twisting 90 will take too much time and require periodic stopping of the astern bell to prevent unintended motion astern. A 90 turn, even if pumping the rudder, will involve significant advance. But using right full rudder, port engine ahead standard, starboard engine back two-thirds will turn you tightly and quickly. Further, if you want to pump the rudder, you can increase the rate of turn by intermittently increasing your port shaft to ahead full. An additional benefit to this approach is that the ship is less subject to cross-wind effects than if you attempted a hard twist next to the end of the pier.
Stomp On It
The Spruance hull is renowned for its ability to accelerate and stop rapidly, which makes it easy to escape a tight spot or charge up to an object in the water and stop on a dime. Yet, when operating in a harbor, it is critical that dangerously high speeds be avoided. I never exceed five knots in a harbor. Around a pier, 20% pitch is my limit. The job is far too delicate to be done at greater speed. On the other hand, if done with discretion and brevity, a sharp ahead or backing bell to begin moving the ship is useful, especially because it limits the time the ship is dead in the water and is most subject to wind and current. Held long enough only to detect its effects, the bell is immediately reduced to a more gentle speed. By "stomping" on a bell like this, you minimize the ship's vulnerability to wind and current without building to a dangerous speed.
An example of this technique can be illustrated in getting the ship under way, without tugs, in a light, on-setting breeze. Once a twist is accomplished—only a few degrees of turn are necessary—and the bow is falling off in the desired direction, accelerate the ship to all engines ahead standard for a few seconds and then reduce to a lesser bell. This will reduce to a bare minimum the time the ship is frozen in a wind-vulnerable position while you wait to pick up speed ahead. Instead of crawling to an ahead momentum, you jump to it.
Cruisers have large amounts of sail area and are vulnerable to bullying by even a moderate breeze, especially at low speeds. A handy rule of thumb is to equate 15 knots of wind to I knot of current in the cruiser. (In a destroyer, it might take 30 knots of wind to equal I knot of current effect.) A cruiser has to be going at least 10 knots to overcome wind effects on the ship. Any lesser speed and you may find your ship crabbing dramatically to stay on track in a moderate crosswind. More important, when nearing a pier at low speeds, the ship is vulnerable to crosswinds-thus, the utility of stomping. Remember that most of the sail area is forward; consequently, a 90 breeze will push the bow faster than the stern.
It is always useful to remind conning officers of something that seems obvious when stated but somehow gets lost in practice: If you are moving ahead and go to a backing bell, the rudders will continue to behave as if you are still at an ahead bell until the moment you begin to move astern. The same is true for going astern and then shifting to an ahead bell. I point this out because, in shifting from ahead to astern or vice versa, many conning officers also shift their rudders immediately, which is likely to make the bow fall off in the wrong direction until the ship moves in the new direction.
The Man-Overboard Problem
It is a challenge for the cruiser is to get around in one wide circle to recover the man in the water. Drop a smoke and order full rudder, all engines ahead flank, and you will be able to turn within your own circle—if the ship is at full power with all four engines on line. But this is impossible at the more typical and fuel-efficient "split plant" (two engines on line) because the rudders are too small to generate enough wash and most ships do not operate routinely at full power. If you are at split plant, adjustments must be made. Either stop or back your inboard engine (more shaft dragging) as your turn progresses; or slow early and then pump your rudder. Whatever you do, try to hit the man. You will not hit him, but try anyway. Distances are deceiving, and if you try for a nice lateral separation, you probably will be too wide.
If you ignore my advice to try to hit the man and end up with excessive lateral clearance, back up. Many people are sorely tempted to twist the ship to the man—but again, the ship twists poorly, especially in a seaway. I have experimented extensively with this and know it is much faster to back smartly and make another approach from, say, one or two ship lengths out.
Getting To and From the Pier
The ship is too valuable (and so are my nerves) to risk high-angle approaches to a pier. Thus, "parallel parking" is the order of the day. For any conning officer, it is infinitely easier to concentrate on the fore and aft positioning of the ship before working on the lateral motion into the pier. I tell the conn we want to come in as flat as possible, no closer than 50 feet from the pier (depending on wind and current). The only job is to move the ship fore and aft so as to position her correctly for the second part of the problem: the final move to the pier using either lines or tugs.
If two tugs are available, they can push the ship in neatly. If one tug is on hand, it can push the bow as the conning officer twists the stern into the pier. Remember that the ship will start to back in a one-third twist, so you may have to stop the astern shaft now and then. If there are no tugs, I consider it far less chancy to come in flat and quite close to the pier—risking scraping paint until positioned—than to come in at an angle that endangers the sonar dome. Flat and close is my rule. Then I always can take lines one and six to power and pull the ship pierside.
For the courageous, a dragging turn, timed just right, will land the ship nicely. I have done that wonderfully—in a simulator. In real life, it is hard to walk away unscathed from a crash landing. And I do so love my sonar dome.
Getting under way is easier. Depending on whether you need to leave the pier in astern propulsion or ahead, the ship's bow or stem can be twisted off the pier quite nicely. All you need is a few degrees—you will back in your twist, which may be a good thing, depending—so do not hold the twist for too long. You just need to be moving in the direction you wish to point before coming to rudder amidships and stomping on it.
Above all, there is more than one way to skin a cat. The particular way I handle a ship may be dramatically different from the techniques used by other skippers. Any number of ways would be fine—as long as they are safe, controlled evolutions. I hope my observations and suggestions will stimulate useful and creative discussions in wardrooms throughout the Navy.
Commander Eyer is commanding officer of the USS Thomas S. Gates (CG-51), which is deployed to Southern Command.