Alternate U.S. Navy

Mark 10 Guided Missile Launching System

The Bainbridges' primary surface-to-air weapon system is a single Mark 10 twin-arm launcher for SAM-N-7 Terrier HT-3 medium-range surface to air missiles (later redesignated as RIM-2). They are the first warships to be specifically built for this variant of the Terrier missile, which is guided by semi-active radar homing rather than radar beam-riding.

The Mark 10 launcher is installed directly in front of the forward deckhouse, with 60 missiles stored horizontally in three 20-round rotary magazines (two on the second deck and one on the third deck). Missiles are transferred forward to a checkout area for manual installation of their guidance fins, then loaded diagonally onto the launcher arms. In the case of a misfire, the launcher automatically traverses and elevates to align with a deck-mounted jettison ram and the dud missile is ejected overboard.

Terrier missile guidance is provided by a Mark 76 Guided Missile Fire Control System, with a Mark 152 fire control computer located in the ship's CIC and two AN⁄SPG-55 guidance radars mounted on top of the bridge roof, one "superfiring" over the other for clear fields of view. This is the same Terrier control equipment fitted on the Long Beach and the Farragut class destroyer-leaders, and represents a substantial upgrade in capability over the older Mark 73 system.

From 1970 onwards, Terrier missiles are replaced on a fleet-wide basis by the newer and more capable RIM-67A Standard Missile ER Block I, which provides performance approaching that of the larger Talos missile in a Terrier-sized package. During their 1995-1998 mid-life refit, the Bainbridges are further upgraded to utilize the more sophisticated RIM-67B Standard Missile 2 ER Block II.

Mark 11 Guided Missile Launching System

The Bainbridges' secondary surface-to-air weapon system is a pair of Mark 11 twin-arm launchers for Mark 15 Tartar short-range surface to air missiles (later designated RIM-24). These are the final missiles of the "3-T" family, intended for close-range defense against relatively numerous air threats using a modified standalone version of the Terrier HT-3's upper stage.

One Mark 11 launcher is installed on the foredeck in front of the larger Mark 10 launcher, and the other one is installed on the quarterdeck. Each launcher has 42 missiles stored vertically in two circular rings; unlike Terriers, Tartars do not require manual fitting of guidance funs and are vertically loaded directly to the launcher arms. As with the Mark 10 launcher, misfires are ejected overboard by seperate jettison rams mounted to the sides of the launcher.

The commonality between Terrier and Tartar systems enables the forward Tartar launcher to share the Terrier system's fire control computer and radars. The aft Tartar launcher is controlled by its own Mark 74 Guided Missile Fire Control System, with a fire control computer in the CIC and two AN⁄SPG-51 guidance radars mounted on the roof of the rear deckhouse. This "1.5" system is considered a significant advantage for the Bainbridge class as it minimizes the number of seperate radar systems which must be carried while still enabling a Tartar system to operate independently while Terrier missiles are being guided.

From 1967 onwards, Tartar missiles are replaced on a fleet-wide basis by the RIM-66A Standard Missile MR Block I, which is both more sophisticated and more reliable.

RUR-5 ASROC

The Bainbridges' primary anti-submarine weapon system is the RUR-5 ASROC anti-submarine missile, which is launched via the Mark 10 GMLS rather than a dedicated launcher. ASROCs are carried in the Mark 10 magazines on a one-for-one basis with Terrier missiles, with a typical combat load being eight to twelve.

Mark 32 Surface Vessel Torpedo Tube

The Bainbridges' secondary anti-submarine weapon system is a pair of Mark 32 triple-tube torpedo launching systems. These are compact, self-contained deck launchers for 12.75" lightweight anti-submarine torpedoes. Mark 44 torpedoes are carried until 1963, and higher performance Mark 46 torpedoes from then on. From 1991 onwards the more advanced Mark 50 torpedo was also available, but these were a limited production model which did not fully replace the Mark 46.

Oto-Melara 76mm⁄62 Compact

The Bainbridges were originally intended to mount two twin 3"⁄70 Mark 37 rapid-fire naval guns for close defense against aircraft and missiles, placed amidships on both sides of the main deck. However, the reliability of this weapon was so poor that the Navy cancelled all further procurment shortly after a small number of examples entered service in 1958. As a result, no guns were fitted to the Bainbridges until their 1966 refits, when two "off the shelf" Oto-Melara 76mm⁄62 Compact single mounts were added.

In U.S. Navy service, the Oto-Melara guns are designated Mark 75 76mm⁄62 and are controlled by a single Mark 68 gun fire-control system and AN⁄SPG-53 gun-laying radar. This is the U.S. Navy's last and most sophisticated analog gun control system, using a hybrid electronic and electromechanical system for its Mark 47 ballistic computer.

Special Munitions

The Bainbridges are authorized for two types of tactical nuclear weapon: the RIM-2D variant of the Terrier missile with a 1-kiloton W45 warhead, and the RUR-5A Mod 5 variant of the ASROC missile with a 10-kiloton W44 warhead configured as a nuclear depth charge. For safety and security reasons, nuclear-tipped missiles were only stored in the lower magazine so that they must be specifically selected and transferred into the upper magazines to be launched.

Post-refit Bainbridges -- like all warships equipped with the Mark 41 vertical launch system -- are also capable of carrying the BGM-109A TLAM-N nuclear cruise missile with a variable yield 5-kiloton to 200-kiloton W80 warhead. However, they are not equipped with the specialized equipment necesary to independently generate the terrain contour and digital image recognition (TERCOM ⁄ DSMAC) maps for Tomahawk missile flights, and are dependent on secure satellite communications to download missile guidance.

Air Search Radar

The Bainbridges are initially fitted with an AN⁄SPS-52 air search radar on the foremast and an AN⁄SPS-40 surveillance radar on the mainmast. These are the standard surface to air radar units at the time of commissioning, as opposed to the experimental SCANFAR system fitted to USS Enterprise and USS Long Beach; the SPS-52 is a one-megawatt S-band system which provides three-dimensional air coverage out to approximately 290 km, while the SPS-40 is a 300-kilowatt VHF-band system which provides two-dimensional air coverage out to approximately 460 km.

As part of their second refuel and overhaul in 1976-1979, the cruisers are upgraded with the newly devleoped AN⁄SPS-48 air search radar and AN⁄SPS-49 surveillance radar. These are, respectively, a multi-beam E- and F-band system which provides three-dimensional air coverage up to 370 km and a 360-kilowatt L-band system which provides two-dimensional air coverage up to 475 km.

Surface Search Radar

The Bainbridges are initially fitted with a Raytheon AN⁄SPS-10 surface search radar at the uppermost position of the forward mast, above the AN⁄SPS-52. This is a relatively small 280-kilowatt C-band system which provides two-dimensional surface coverage up to 60-80 km.

As part of the second refuel and overhaul in 1976, an additional AN⁄SPS-55 surface search and navigation radar is installed at the uppermost position of the mainmast. This is a solid state 130-kilowatt X-band system which provides two-dimensional surface coverage up to 90 km, as well as short-range, high-resolution air search as a backup to the primary air search radars.

As part of the third refuel and overhaul in 1985, the AN⁄SPS-10 is replaced by the newer AN⁄SPS-67 short range surface search and navigation radar. This is again a 280-kilowatt C-band system (and in fact reuses the existing antenna), but utilizes solid-state digital components and also integrates an L-band identification-friend-or-foe (IFF) subsystem.

In an additional electronics refit in 2003, the AN⁄SPS-55 is replaced with a new Hughes AN⁄SPS-73 short range surface search and navigation radar. This an off-the-shelf system based on the commercial Furuno FAR-2117 navigation system, which is a solid-state X-band system with a new digital console which allows for integration with other ship systems. Also installed at this time is an AN⁄URN-31 commercial off-the-shelf Class A transciever for Automatic Identification System (AIS) transmissions as provided for under the International Convention for the Safety of Life at Sea (SOLAS) treaty.

Sonar

The Bainbridges are among the first ships fitted with the AN⁄SQS-26 sonar system, which goes on to become the standard surface ship sonar package fitted to almost all new U.S. Navy surface combatants from the 1960s through the 1990s. It is a 66-kilowatt combined active and passive sonar, with an effective range of eighteen to sixty-four km depending on mode.

As part of their second refit in 1976, the AN⁄SQS-26 is replaced by a newer AN⁄SQS-53B sonar system, which utilizes advanced solid-state electronic components and digital data processing. The SQS-53B is designed to be tied into the larger-scale AN⁄SQQ-89 Undersea Warfare ⁄ Anti-Submarine Warfare Combat System, but this is not fitted to the Bainbridges at this time as they do not have a shipwide integrated combat system.

Reactors

The Bainbridges' nuclear fission reactors are developed by General Electric as the “High Powered Reactor”, a surface ship spinoff of the “Submarine Advanced Reactor” program which had produced the S4G reactors for USS Triton. Because the Bainbridges are originally classified as destroyer-leaders, the Navy designates these reactors as the D2G: “Destroyer, second model, General Electric”. Like all U.S. Navy reactors (except for the experimental S2G), they are pressurized water reactors (PWRs) operating on highly enriched (93%) uranium fuel, with a thermal output rating of 148 megawatts.

In contrast to the earlier Enterprise nuclear propulsion plant which fitted eight reactors as one-to-one substitutes for conventional furnaces and steam boilers, the Bainbridges'nuclear propulsion system is configured with two reactors with three steam generators each. The steam generators are heat exchangers which transfer thermal energy from the superheated liquid water (1250 PSI ⁄ 550 F) circulating in the primary cooling loops to boil distilled seawater into saturated steam (600 PSI ⁄ ~550 F) which then circulates in the secondary cooling loops.

Superheaters

While nuclear fission is an incomparably higher-energy source of power than combustion, the substitution of nuclear reactors and steam generators for conventional furnaces and boilers does introduce a number of technical challenges. The most significant of these is that a sustained fission reactor operates at a much lower temperature than a combustion furnace and therefore cannot efficiently heat "wet" saturated steam from the steam generator into more energetic “dry” superheated steam. As a result, a nuclear plant must typically utilize large half-speed turbines suited for a high mass flow of steam and also requires the placement of a moisture separator reheater unit between the high-pressure and low-pressure turbines.

The Bainbridge propulsion plant adopts the alternative solution of routing the steam from each reactor through a set of seperately fired (electric) superheaters before it reaches the turbines. These external superheaters convert the saturated steam into 600 PSI, 850 F superheated steam; however, unlike normal convection superheaters placed in the gas flue of a combustion furnace, the additional heating is performed at a relative loss rather than efficiently recycling heat energy which would otherwise be lost in the exhaust. Nonetheless, the reactor plant has power to spare and the provision of superheated steam is a substantial net gain for the turbines.

Turbogenerators

Outside of the reactors, the Bainbridges' propulsion plant is a turbo-electric drive very similar to the ones previously used in legacy American battleships and armored cruisers. The resurrection of turbo-electric propulsion in the Bainbridges reflects both the innate advantages of this method of propulsion and the increasingly massive demand for electrical power on board a modern warship.

As in the previous generation of naval turbo-electric plants, the propulsion machinery is vertically divided across deck levels: the reactors and turbines are on the fourth deck, while the main motors and propeller shafts are on the machinery deck below. For maximum system redundancy, the reactors are widely seperated into forward and aft reactor compartments and each has its own fully independent control room, although they are also cross-linked so that either control room can take emergency control of the opposite reactor if necessary.

The forward and aft turbogenerator rooms are located directly adjacent to the forward and aft reactor rooms respectively, each with two turbine sets seperated by a longitudinal firewall. Each turbine set consists of one high-pressure turbine, one intermediate-pressure turbine, and one low-pressure turbine which are all synchronized on a common driveshaft. Because both reactors are always active, steam piping is more streamlined than in other naval plants; steam from each reactor can be fed to either or both turbines in the corresponding turbogenerator room, but cannot be cross-fed to the turbines in the opposite turbogenerator room.

Motors

The Bainbridges have a "destroyer style" two-shaft propeller arrangement with two 15,000 SHP three-phase induction motors per shaft. The use of high frequency alternating current as the power source enables these motors to be much more compact and lightweight than standard frequency AC motors of the same power output, although complex polyphase wound rotors are required for speed control.

Refueling

The original fuel cores in the Bainbridges’ D2G reactors have a life span of five to six years, but progressively improved fuel cores with longer lifespans are installed during every refueling cycle. The first refueling takes place in 1968-1970, the second in 1976-1978, the third in 1985-1987; each "Refuel and Overhaul" (ROH) process also involves substantial modernization and upgrading of rest of the ship while it is in drydock, and takes approximately two years to complete.

During the 1995-1998 mid-life refit, new C1G reactors are installed with fuel cores that last for the remainder of the ships' active duty careers.