One can make the case that the new riverine forces are waterborne counterparts to 19th-century cavalry. They are being organized and trained for lightning attack, recon, patrol, and convoy—core missions for horse soldiers in the Old West. Like their mounted predecessors, the capability of their steeds is central to success. Much attention has been devoted of late to the form those mounts will take.
A close liaison between the small-craft industry and its military customers is yielding a new understanding of the realities of the brown-water environment. The Navy is struggling to determine and quantify its needs as it develops tactical doctrine following decades of neglecting riverine warfare. Experience in Iraq, South America, and with numerous allies in Africa and Asia, has served as a proving ground for what works and for where change is warranted.
The ongoing conversation has shown that in the vagaries of riverine combat one size or type vessel does not fit all requirements. How the demand for specialization will be incorporated with the institutional drive toward standardization remains to be seen. Based on military requirements and civilian ideas, three basic types of riverine craft are emerging: light, fast, and versatile recon and attack craft designed to find and fix targets; heavier, well-armored mini-gunboats and assault troop carriers designed to close with and destroy an enemy; and river transports capable of carrying heavy loads of troops or cargo in a dynamic, shallow-draft environment.
A Dichotomy in Design, Function, and Construction
While the domestic trend is toward higher technology and innovation, this philosophy is self-defeating in many of the areas where the river craft will deploy. The new boats are being marketed to foreign navies as well as our own, and therein lies a conflict. Rear Admiral Donald Bullard, former Commander, Navy Expeditionary Combat Command, recently noted that advanced technology cannot be supported in some regions. Technicians in many locales can rebuild a standard carburetor but are helpless when confronted by the need to use a laptop to tune a modern fuel-efficient outboard. Yet, the Navy is quick to call for commonality of engines, weapons, electronics, and drive trains in an ongoing effort to reduce the logistics tail. The solution may lie in identical hulls being offered with two or more suites of systems and weapons.
Admiral Bullard stated the Navy's needs succinctly. First, speed is critical to survival. The boats must be both fast and maneuverable. Force protection, i.e., armor, is another vital element in survivability of crew and craft. Riverine warfare takes place in constricted battle zones, the closest any modern Sailor is likely to come to the muzzle-to-muzzle ranges of the age of fighting sail. Armor must be strong enough to protect the crew and the vessel while remaining light enough to not reduce speed. The crew must be able to return fire accurately and in volume, a challenging requirement from a small boat bouncing along at 40+ knots. This supports the tendency toward stabilized weaponry. Intelligence, surveillance, and reconnaissance capabilities, sensors, and the ability to employ unmanned aerial vehicles round out Bullard's guidelines.
Joshua Iverson, riverine veteran and currently Riverine Functional Team Leader for the Navy's Center for Security Forces, is quick to supply specifics. Iverson's experience in Iraq and the tropical estuaries of Colombia have led him to conclude that different geographical and environmental conditions demand variations in craft and equipment. The conflict with the drive to standardization is obvious, but Iverson makes a good case for differentiation. While some conditions call for a variation in power plants and armament, sometimes a simple change in camouflage scheme can adapt a boat to a new locale or season.
He notes that boats in Iraq are generally stored on trailers in secure compounds and towed to launching sites. The convoy, launch, and recovery operations expose operators to ambush at a time when they have either restricted road speed or are stationary. A limited number of launching sites makes for easier targeting by enemy forces and sites may need to be graded to carry the load. Such launching operations are also extremely difficult at night. Ease of transport on land remains a desirable element, with rugged trailers that can launch from primitive sites, provide hull protection against improvised explosive devices while in transit, and help to recover a damaged vessel.
Iverson states unequivocally that hulls must be strong and durable enough to withstand frequent groundings on rocky bottoms, possess armor proof against small arms, and have a bow door for personnel, self-cleaning intake strainers, and back-flushing capability. He insists that speed is critical to survival and that the highly maneuverable jet drives fill this role well as long as their impellers and turbine blades can withstand the rigors of the combat environment.
Low-lying cables and bridges limit access, and the former are extremely dangerous, especially for bow gunners. Water levels are subject to constant, sometimes hourly change, often controlled by the locals through dams and spillways. These aspects reinforce the need for low-profile craft. The highest points on the boats are the ones most likely to be hit by small arms fire, as verified by a study of casualty figures from Vietnam and the World War II PT boat experience in the Pacific. This is one reason why law enforcement vessels are at risk in combat—they tend to be tall and top-heavy. A glance at the successful PT boats and those of the post-war era, including the Nasty-class fast patrol torpedo boats of the 1960s, shows that designers and selection boards consistently appreciate the importance of low superstructures and weaponry.
What is Industry Offering?
Captain Evin H. Thompson, Commodore, Naval Special Warfare Group Four, has called the riverine force a direct descendent of the torpedo boats of World War II. While the lineage claim has validity, the form their offspring has taken would amaze PT veterans. Small combatant craft have evolved remarkably since even the invasion of Iraq. A few years ago rigid inflatable boats dominated this market. These boats, open craft of limited capabilities, were previously a staple of riverine warfare due to the absence of other alternatives. Thanks to recent developments they have largely been relegated to security, police, and low-intensity patrol functions. Innovative newcomers are steadily usurping their combat role.
One of the most novel concepts comes from a partnership between Lockheed Martin and Gibbs Technologies. Claiming that high-speed amphibious vehicles are the next generation of combat craft, they are offering three types and sizes of road-worthy, wheeled amphibs designed as both transports and assault craft and carrying up to 20 people. Such craft are not new, having been pioneered by the German Wehrmacht in 1939. But until recently they had water speeds of less than seven knots. Lockheed claims their combat craft can deliver 50-80 mph on land and 35-50 knots on flat water.
If the prototypes prove successful they could be a tremendous breakthrough in assault and transport craft, allowing immediate transit from water to land and vice versa. The ability to dispense with trailers, launching sites, and towing vehicles would reduce troop and crew exposure and reduce or eliminate the need for waterside support facilities. This is asking a lot from any system, and the realization of these goals and the ability of the amphibians to stand up to the rigors of combat cause the future of the type to remain in question.
The merger of proven ideas with modern materials and technology is apparent in the prototype Joint Multi-Mission Expeditionary Craft (JMEC). With hull design and construction by Aluminum Chambered Boats of Bellingham, Washington, twin jet drives, turbocharged diesels, and systems by Northrop-Grumman, JMEC is a clear example of private joint ventures capitalizing on various corporate strengths. The same aluminum hull is offered in five configurations that fulfill each of the three basic riverine tasks. In the hands of a skilled coxswain the slab-sided, bluff-bowed boat is remarkably fast and maneuverable. With modular adaptability to changing missions, the JMEC offers a preview of the type of craft that can address the Navy's institutional mandates.
Coastal and riverine capabilities have long been a focal point in allied navies more concerned with homeland security than projection of power abroad. Thus, it is not surprising that some U.S. firms are looking overseas for suitable shoal-draft combatant craft. SAFE Boats International recently obtained license to produce the Swedish CB90 at its Washington state facility. This multi-mission craft can be used as a mini-gunboat, but it is especially suited as an attack troop transport. It can be armed with mortars, missiles, and a variety of automatic weapons, all of them stabilized and remotely operated. The CB90 is a proven design already in service in several NATO nations as well as Mexico, Malaysia, and Russia. Why go abroad for an assault boat? SAFE Boats President Scott Peterson said "SBI knew the Navy needed something in a short amount of time . . . there was not the time to develop a boat from scratch. Then we started doing our homework on the most evolved riverine craft around the world and the CB90 continued to come up."
Out of the Past
Some of the new shallow-water warriors may look familiar. Virginia Electronic Systems (VES) has teamed with Associated Naval Architects to breathe new life into the Mini armored troop carrier (ATC), a late-1970s vintage boat. This barge-like 36-foot-long vessel was designed around lessons learned from Vietnam and is powered by twin commercial turbocharged diesels coupled to water jets. Its bow ramp design was heavily influenced by SEAL operations. The aluminum hull carries high-tech armor and is reported to draw only a foot of water when planing at high speed. Draft at rest is 2.5 feet, and the craft features a low-profile hull extending a mere 6 feet off the water. Capable of carrying 15 troops at speeds of 28 knots, the ATC has found a new role through an ongoing U.S. initiative to use riverine forces to aid Colombia's counter narcotics efforts. Unlike some of the craft described previously, the ATC is a completed weapon-in-being, its design and development having been paid for decades ago, and thus far less expensive to revamp and put into active service.
Other current and vintage vessels offer less potential. The Patrol Boat, River (PBR) and the Patrol Craft, Fast (PCF), also known as Swift boats, of Vietnam were compromise craft acquired as a matter of expediency and are no longer in service. The PBR was largely a Hatteras design but built by a firm in Washington state. That company went out of business decades ago, and the molds are long since gone. No great loss though, since both types had problems. Neither was exceptionally seaworthy. The PBR had some engine and drive problems, and the Swift boat was far too tall and slow for modern operations.
It has been suggested that the Coast Guard's recently completed Response Boat, Medium (RBM) might be modified for riverine combat but savings are problematic. Law enforcement and small combatant craft face radically different missions and to convert the RBM for the latter task would mandate a complete change of superstructure, deck, equipment, and weaponry. The addition of this gear plus armor would probably throw the boat far off her design lines and ruin performance. At any rate, the cost savings of using an available hull would be small since the hull accounts for 20 percent or less of the cost of a combat-ready boat.
The Need for Speed
Speed and rapid acceleration are vital to survivability in the close quarters of riverine combat. Vietnam river transports and monitors typically had speeds of no more than 15 knots, and 10 knots or less was not uncommon. Today any vessel that cannot continuously exceed 30 knots will not make it off the drawing board. A loaded speed of 40-50 knots is the new norm. Jet drives have become the drive train of choice in most riverine craft, and they are almost exclusive in combatants. Their ability to operate at high speeds in very shallow water has resulted in a new generation of boats whose draft is measured in inches instead of feet. They accelerate quickly, have the potential to maneuver faster and tighter than conventional drive trains, and can often run at high speed in less than a foot of water.
There are drawbacks, however. Inducted rocks and other forms of solid debris routinely damage impellers, blades, and fans, reducing speed and destroying drive trains. Jet drives lack the hydrodynamic "bite" on the water of propeller systems, and this impacts their maneuverability. To compensate they need to be paired with hulls possessing bluff bows with slight deadrise forward and deeper V sections aft—exactly the opposite of the characteristics sought in a good sea boat.
Outboards continue to be much in evidence and are often found paired with rigid inflatable boats. The powerhead and much of the drive train is exposed to gunfire so this engine type is most frequently seen in the law enforcement and security role. The majority are four-stroke models, already successful in commercial and recreational applications for their quiet, fuel-efficient operation. Despite their exposure to hostile fire, outboards afford quick and easy exchange of worn or damaged engines so they may retain a combat presence in remote or primitive areas where tech support is limited. The Department of Defense is seeking to reduce the multiplicity of fuels in use, and outboards will need to adapt to this while remaining lightweight and user-friendly if they are to remain with combatant forces. Inboard/outboards are rare, and conventional inboard drive trains involving shaft, struts, and propellers have been discarded in brown-water prototypes.
The Human Factor
Any craft is only as good as its crew, and the boats and men of the riverine force operate in a harsh and challenging environment. High-speed craft are subject to repetitive impact loads, and even the fittest Sailors will experience decreased efficiency and effectiveness as a result. Continued exposure to impact, high-speed maneuvers, lifting, and leaping often has long-term negative repercussions and can result in permanent disability. In recognition of this, boat designers are making shock-absorbing design and construction an integral part of the production process.
Spring-, hydraulic-, or pneumatic-loaded seats are increasingly common, and the same technology is being employed to alleviate adverse impacts to sensitive onboard equipment. On some craft it is primarily the crew that benefits, but in others advanced ergonomics are being harnessed to reduce fatigue on troops being transported to battle. This is the case with the CB90. Deck cushioning consisting of interlocking plates reminiscent of top-flight athletic shoes is common in most new designs.
Aluminum is increasingly the material of choice in these boats. Noise while under way is a common drawback of aluminum hulls, and manufacturers seek to lessen this with a variety of coverings and insulation materials. Current capabilities are being advanced by sound deadening coatings that can be applied to almost any metallic or composite surface. The resultant noise reduction is not only an aid to covert operations but makes for a friendlier work environment for crewmen. Taxpayers and Sailors will appreciate the consequent reduction in hearing loss and disability claims.
Even air conditioning has become a common component in the new prototypes, and why not? When operating in temperatures of 120 degrees it is an important feature for efficiency of crew and equipment.
Systems Development
A small combatant is much more than hull and power plant. It is a complex amalgam of mechanical, electrical, and weapon systems designed to keep its occupants alive while maximizing effectiveness and lethality. Modern combatants feature multiple computerized systems including steering, navigation, communications, target acquisition, and engagement.
Compared to the boats they operated in the 1960s, Vietnam-era vets would be amazed at the proliferation of laptops and computer-guided weaponry and systems management that is considered both d'rigueur and essential on board the next generation of small naval combatants. Night vision devices integrated with optically controlled heavy caliber direct fire weapons are widespread. Automatic fire tends to draw an opponent's attention and return fire. Therefore, increased use of remote-controlled weaponry helps remove the gunner from the field of fire and allows him to concentrate on killing the enemy instead of dodging incoming rounds. Not every weapon is a gun, however. Installation of non-lethal acoustic weaponry for security and law enforcement craft is gaining wide acceptance.
State-of-the-art navigation gear occupies much of the cockpit panel in many new offerings to include GPS, depth finders, and cameras integrated with screens to pinpoint an opponent's position. Thermal imagers are becoming standard equipment, interfaced with optical cameras to show both the forest and the hostile elements it can conceal. Compact equipment for internal and external communications has long been a feature of land and riverine vehicles and continues to be in evidence but in a refined, miniaturized incarnation.
Steering wheels are rapidly losing out to joysticks, and spring-loaded, electrically activated toggle controls are much in evidence. They eliminate the wear and corrosion found in shift and throttle cables with welcome weight reductions and easier maintenance. The new controls also occupy less space in cockpits already packed with electronics and are ergonomically friendly to the operators.
Capability Gap
High-speed boats, sophisticated electronics, jet drives, and high rev engines generally have a single thread in common: expense. When these items are placed in combat the harsh usage and environment decrease useful life dramatically. The result is a budgetary strain that can reduce or eliminate even the best systems. Iraq and the war on terrorism have led to an infusion of money into a hitherto cash-impoverished realm of U.S. naval endeavor. But "infusion" can be relative. As Admiral Bullard candidly noted, "Fiscal realities are there and are going to come crashing down, in my opinion." Therefore, reliability and ease of maintenance in the field remains critical for reasons of combat dependability, readiness, and to meet budgetary realities.
Regardless of cost, administration officials will eventually have to make tough choices between maintaining the status quo or spending a lot more on new boats. Since the military is the only segment of government and society making sacrifices for the misnamed Global War on Terror, precedent does not paint an optimistic picture.
Another disturbing factor is apparent. A review of these specialized craft and the current blue-water inventory reveals a dangerous shortcoming in the Fleet mix. The U.S. Navy has enjoyed a dominant presence on the high seas for a century. Limited power is slowly being produced for the riverine component. Yet, there exists a clear gap between these two capabilities. Where are the gunboats, missile patrol boats, and assault craft of greater seaworthiness than their brown-water cousins and of less draft and expense than the blue-water ships? Where are the platforms needed for waters at once open and confined such as the Philippine and Indonesia archipelagoes, the shoal near coastal waters of southeast Asia where pirates proliferate, and similar shallow seas? The Littoral Combat Ship is too large and far too costly to fill this role. The Navy still lacks a compact, seaworthy, potent, and efficient vessel for control of the green-water battlespace. Bridging the green-water gap may be industry's and the Navy's next challenge.