The Navy of the 21st century will have to operate close to hostile shores—where large, expensive Aegis combatants may not be the best choice. Enter the small, stealthy, semisubmersible Guerrilla Warfare Ship.
When President John F. Kennedy said, "Complementing the achievements of greater ships in greater waters," he was referring to the PT boats of World War II, but his implication that there is a need for specialized combatants to complement the capital fleet still rings true. The Navy has maintained a blue-water capability almost continuously since its inception, but it also has had visionaries who created vessels and tactics to address unique prevailing warfare requirements. The gundalows of the Revolutionary War, the monitors of the Civil War, the PT boats of World War II, and the riverine assault boats of Vietnam each answered the need to project power into a focused maritime environment. Today, the Navy is awaiting the introduction of the evolutionary DD-21, but we need to analyze whether this combatant will fill all our needs to counter the post-Cold War threat.
By 2015, surface combatant forces will consist only of DD-21s, Arleigh Burke (DDG-51)-class destroyers, and Ticonderoga (CG-47)-class cruisers—each of which has a unit cost in the $800,000,000 range. The loss of a single Aegis platform would be a significant hit to the surface inventory and would have serious strategic and international ramifications. Despite their multimission capabilities, these monolithic capital ships cannot and should not be used in maritime environments in which their size, capability, and logistic umbilical outstrip their functionality.
The Navy needs the power projection and open-ocean capabilities of the aircraft carrier and her escorts, but we must acknowledge the requirement for a true littoral offensive and defensive naval vessel if we are ever to achieve the full-spectrum dominance advocated in "Joint Vision 2010." The focus of future warfare will be on operations close to hostile shores to support the Navy's expeditionary warfare.
There is an enormous void between the proposed 12,500-ton DD-21 and the boats of the Special Boat Units and Inshore Boat Units. Aegis platforms are the ultimate maritime domination vessels, but it is imperative that we remove the requirement for them to perform static littoral defense close to the beach. They must be complemented by a vessel designed for littoral domination. If naval forces are to be capable of 21st-century operations, a small, stealthy, highly automated, semisubmersible craft with long on-station loitering, high-speed strike/egress capability, and strong unmanned remote sensing capabilities for surface and subsurface environments, that is rapidly reconfigurable from a forward deployed support vessel or base, must be programmed into the U.S. Navy's shipbuilding agenda.
This leads us to the development of a Guerrilla Warfare Ship that would address the following mission areas:
- Littoral battlespace domination
- Maritime embargo
- Precision engagement
- Surface and subsurface surveillance and choke-point traffic monitoring
- Interdiction of littoral traffic
- Commerce raiding
- Special Forces delivery and extraction
- Protection of the amphibious assault lines of communications, which will extend over the horizon
Vessel Characteristics
Two Guerrilla Warfare Ships are sitting semisubmerged at the entrance of a strategic choke point, their skins awash as winds whip wave caps over their exposed "whaleback" superstructures. They have submerged themselves until only their sensor arrays, communication arrays, guns, exhaust-intake louvers, and cockpit view ports are above the waterline. Low-speed propulsion pods hold them in an autopilot station-keeping loiter. The vessels are electromagnetically silent, with the exception of highly focused links to unmanned aerial vehicles (UAVs) and infrequent satellite uplinks. They loiter like alligators: good eyes, low silhouette, great potential speed, dark-skinned, nocturnal, and extremely lethal.
The Guerrilla Warfare Ship would be very mission flexible, with modular mission suites (sensors, weapons, and operator stations) built to be lowered into the vessel's body and connected into its electronic spinal cord, electrical-distribution, damage-control, and auxiliary systems. Each interchangeable surface, subsurface, air, and special warfare module would be serviced, installed, and repaired by mobile maintenance crews. Module exchange—which would allow us to put the right force, at the right place, at the right time—could be accomplished in a single day with a plug-and-play networking capability.
To complement its stealth design, a variable depth-control capability would allow the vessel to "squat" in a semisubmerged (or even fully submerged) posture—an especially useful feature when on station in a littoral surveillance and deterrence role. The vessel would show no discernible thermal signature or radar cross section in its semisubmerged state. Configured to discharge its ballast water rapidly and step up on the foil-assisted, wave-piercing twin hulls to reach speeds in excess of 60 knots, the vessel also could rise to the standing position while in port or during hull maintenance.
The crew would monitor live sensor data from the UAVs launched autonomously from stowage cells beneath the vessel's skin. As the target comes into view of the airborne sensors, targeting information is passed to the vessel's medium-range antisurface missile battery. The main engines are started, the UAV is commanded to maintain contact for battle-damage assessment, and the missiles are launched. As the vessel picks up speed it rises from the water into the sprint mode. Approaching 60+ knots, it heads toward its next littoral hide. The UAV rendezvouses with the ship following battle-damage assessment.
As in any guerrilla warfare operation, stealth—to keep the element of surprise—is paramount. In the maritime environment, electromagnetic, thermal, visual, and acoustic signatures are key stealth characteristics.
The vessel would take advantage of all current work on passive minimization of radar cross section. Radar-absorbent material would be used on exposed surfaces. There would be no mast, lifelines, flight deck nets, ladders, or exposed hatch mechanisms. Exterior hatches would have smooth exteriors using watertight/airtight aircraft door technology. The ability to squat into a semisubmerged posture also would greatly increase the vessel's stealth. As an active stealth measure, the vessel's communication systems would leverage the apparent emission control of highly focused satellite uplinks.
Thermal stealth in the littorals is equally critical. The proliferation of thermal, infrared, and enhanced-light imagers makes it simple for enemy coast watchers and intelligence collectors to locate and target maritime assets that are posted in the littorals. The majority of the time, the Guerrilla Warfare Ship would be sitting on the coastline at idle in the squat position conducting surveillance. During this time, its generator and ventilation systems would be exhausted below the water's surface to reduce the thermal signature. The radar-absorbent material on the exposed hull would serve the secondary functions of anechoic insulation and hull thermal signature suppression.
A heavy emphasis on nocturnal capabilities would be incorporated in the vessel's design. The crew would be supported by thermal, infrared, and enhanced-light optics to give them virtual daylight conditions. In addition, navigation aids would be used that allow the crew to feel comfortable holding position a few hundred yards offshore at night to leverage the shoreline clutter of the littorals.
Sensors and Communications
This vessel would have modularized sensor and weapon packages that would be tailored to fit mission demands. These packages would be configured and installed at a forward base or a mothership, and could be upgraded and repaired independent of the hull. As needed, the modules could be lifted from the vessel and replaced by preconfigured modules for specialized command-level antiair, command and control, or special operations delivery. Modules would be compatible with Air Force lift capabilities and might include:
- Littoral battlespace denial (combinations of antisurface, antisubmarine, or antiair sensors and weapons)
- Special Operations Forces delivery, extraction, and support
- Mine detection and countermeasures
- Command and control
- Replenishment capabilities to serve other Guerrilla Warfare Ships
Self-contained weapon modules; Special Warfare planning, berthing, and equipment storage cells; command-and-control cells; and fuel, food, and ammunition replenishment cells could be configured and prepared for deployment independent of the vessel.
For survival in the age of electronic surveillance measures and remote targeting, maximum use of focused satellite communications systems and remote autonomous vehicles would provide a high level of apparent emission control. UAVs would provide continuous live remote sensoring back to a "silent" Guerrilla Warfare Ship, to reduce the probability of detection while the vessel sits in a littoral hide. Sikorsky's Cypher is an excellent example of an air vehicle to support long-range remote sensing, communications relay, and countermeasures from a small minimum-manned sea-based platform. The Cypher is a vertical takeoff and landing (VTOL), "hands-off" smart air vehicle capable of autonomous operations, with position hover-hold, waypoint navigation, and auto return home features. In addition, its shroud-enclosed rotor reduces the inherent risk of operating rotary wing aircraft on a small ship. Any UAV incorporated into this vessel must mirror the passive stealth characteristics of the Guerrilla Warfare Ship.
Another option for modular configuration is to load an antiair warfare radar suite and complementary weapon package. Specialized to provide radar coverage overland, these radar systems would limit the exposure of the Aegis ships in the littorals.
A strong antisubmarine warfare capability using underwater unmanned vehicle capabilities could be built into a launch-and-recovery module. These robotic unmanned craft with passive and active search capabilities also could be used for antisurface warfare and mine hunting.
Weapons
There would be two classifications of weapons—organic weapons that are required for every sortie, and modular weapons that would be loaded to meet specific mission requirements.
Systems such as infrared decoys, chaff systems, a stabilized main gun, and a secondary stabilized smaller caliber gun would be installed permanently, to maintain minimal offensive and defensive capability. The gun combination could be a stabilized 105-mm low-profile gun and an automated 25-30-mm gun, which would give the crew a short- and medium-range capability. To conform to the minimum manning inherent in future ships, the gun systems must be optically slaved and locked, incorporating a smart gun fire-control system that could identify and lock on to rudder areas, engine rooms, and pilot houses. Advances in gun reloading systems developed for aircraft weapon systems and Army armor reloading would be incorporated, so the vessels could feed ammunition directly into magazines accessible through the skin of the ship. This would reduce the manpower needed to load weapons during engagements and replenishments.
The modular weapon systems would include a medium-range antisurface missile such as Harpoon to cover surface engagements out to 50-60 nautical miles and rocket-thrown depth charges to counter the littoral threat of swimmer delivery vehicles, minisubmarines, and swimmers.
On-station Capability
The fundamental premise of the Guerrilla Warfare Ship is to provide a vessel with open-ocean cruising capability that could operate for a minimum of 21 days without replenishment. There would be no traditional replenishment-at-sea capabilities, but the ability to replenish vertically would be incorporated. Tactically, it would be prudent to use food and fuel replenishment capabilities evaluated for Special Operations Forces. Fuel bladders and food modules dropped by aircraft could provide continued endurance for vessels maintaining a littoral hide.
Repair parts and damage-control inventories would be contained in modules that would be loaded as complete kits at the start of each mission. The advanced base or mothership would maintain these modules.
Engineering, Hull Form, and Maintenance
Sprint speed for the Guerrilla Warfare Ship would capitalize on the technical advances made in the maritime fast ferry market. This industry is achieving 60-plus knots with vessels up to 800 tons with swath and wave-piercing catamaran hulls. Coupled with computerized stabilization systems to reduce pitch and vertical acceleration, these hulls could provide the U.S. Navy with a formidable high-speed platform.
An evaluation of both diesel and gas turbine main propulsion is appropriate, because both have provided dramatic surface speeds. To reduce fuel consumption, diesels would be used for electrical power for ship service and electric propulsor motors. These propulsors primarily would be used for docking and on-station loitering.
Design considerations would include the ability to dock a fully loaded vessel into the well deck of an LPD-17 Whidbey Island (LSD-41)-, Harpers Ferry (LSD-49)-, Anchorage (LSD-36)-, Tarawa (LHA-1)-, or Wasp (LHD-1)-class amphibious ship. To ensure this fit, the craft's displacement would be less than 600 tons, length less than 200 feet, beam less than 47 feet, and draft in the hull-up position would be approximately 5 feet.
The sound-dampening lessons learned would be incorporated throughout the engineering systems to reduce the probability of acoustic detection while the vessel is sitting in the hull-down surveillance posture.
As a design goal, no maintenance would be conducted during the 21-day underway periods. All maintenance requirements would be geared for accomplishment by the mothership or land-based repair teams. Redundancy of critical equipment would allow the crew to maintain operations following component failure. The concepts of reliability-centered maintenance, practiced by the commercial aviation industry, would serve as the benchmark.
Chemical and biological weapon detection and filtration systems would be needed to protect the crew from the increasing probability of "cheap nukes." Highly automated damage-control systems would be built into the hull to support the minimum-manning concept.
Manning and Motherships
To avoid excessive space demands for internal habitability, the Guerrilla Warfare Ship would be manned by approximately 20 crewmen (3 officers and 17 enlisted personnel). Manning would be driven by the zero-base concept in which a crew billet would be incorporated only if there were no technological equivalent. The focus of the crew would be on operations, and the use of shore-based or mothership maintenance teams would alleviate the need for sea-based technical repair.
To further reduce the onboard manpower requirement, the vessel would be built with embedded training capabilities. Insertion of synthetic data into the navigation suite, combat system, and engineering control system is critical to gaining valuable training opportunities through simulation technology.
Another concept to maximize the operational availability of the vessel would be the two-crew concept used in the ballistic-missile submarine fleet.
To sustain expeditionary warfare, these vessels would remain forward deployed, supported by a mobile repair and replenishment mothership. Mothership capabilities would include vessel repair, engine swap, engineering system overhaul, electronics repair, debilitated vessel transport capability, unmanned aerial and underwater vehicle overhaul, crew rest, food module replenishment, repair parts storage, and weapon/sensor module replenishment. Umbilicals from the mothership would provide satellite network-centric connectivity, electricity, water, and fuel. The best candidate for the mothership role would be a slightly reconfigured LSD or LPD.
Fight and Win in the Littorals
The U.S. Navy is certain to operate in support of expeditionary warfare in the littoral arena for the first part of the 21st century. To contemplate full-spectrum littoral dominance seriously, it is imperative that the Navy focus a portion of its shipbuilding program on this unique requirement. If we expect to fight and win in the littorals, we must capitalize on today's speed, stealth, and information superiority technology and build a vessel to complement the current blue-water multimission ships.
Commander Weeks is commanding officer of Inshore Boat Unit 17, and previously was operations officer of a mobile inshore undersea warfare unit. While on active duty he served on the precommissioning crew of the Arleigh Burke (DDG-51), as chief engineer of the Mobile Bay (CG-53), and as a staff operations officer at the Naval Special Warfare Command. In his civilian career as a program manager for SAIC in San Diego, he focuses on the integration of emerging technologies for the U.S. Navy.