CONNECTION TO THE FUTURE

U.S. Navy is Eyeing Game-Changing T-Craft Concept for Next-Generation Expeditionary Watercraft Force.

by Marty Kauchak, MLF Correspondent

Sea basing, as initally described in the U.S. Navy’s Seapower 21 strategy, will allow the U.S. DoD to move forces tailored for specific missions globally at high speed. One key element of the evolving sea basing concept is that forward deployed forces will no longer establish beachheads, iron mountains or large headquarters operations similar to those supporting Operation Iraqi Freedom. These facilities and functions will be moved from land to a sea base over the horizon—well beyond the operating range of contemporary amphibious forces and their expeditionary watercraft.

The maritime services’ evolving plan for a sea base calls for geographically-dispersed units of an expeditionary strike group, a carrier strike group and maritime prepositioning force (future) (MPF(F)) ships—linked by an information network—to operate independently of in-theater ports and other facilities. An Office of Naval Research (ONR) Innovative Naval Protype (INP) effort to field a sea base connector–transformable craft (T-Craft) prototype demonstrator would bolster the embryonic sea base concept by providing rapidly moving heavy payloads from sea base units to shore and serving as an “assault connector.”

GAME-CHANGING, RISKIER EFFORT

The T-Craft program began in 2005 and is funded at about $225 million through the budget outyears. For oversight and accountability purposes T-Craft is in a portion of the ONR Science and Technology (S&T) portfolio that is designed to demonstrate a capability, and is part of a broader INP focus for sea basing. S&T programs are one of the service’s ways to obtain cutting edge technology. “They should in and of themselves be game changing and riskier than an acquisition program could afford to be,” pointed out Kelly Cooper, program manager, T-Craft, ONR.

A completed nine-month, T-Craft Phase I effort was for concept development. “If you did compare this to an acquisition program, that was for concept refinement,” explained Cooper. The on-going Phase II is for technology development.

The ONR’s 2005 broad agency announcement (BAA) that is the underpinning of T-Craft contains a broad vision for the program and eight supporting capabilities. These criteria would allow the craft to revolutionize intra- and inter-theater sea-based logistics.

The T-Craft is envisioned to deploy in an unloaded condition (range of 2,500 nm) from an intermediate support base to the sea base and then be used as a sea base connector, transporting wheeled and tracked vehicles, and cargo through the surf and onto the beach.

The expeditionary craft is expected to have three general modes of operation: a fuel-efficient, good sea-keeping mode during open ocean transits; a high-speed, shallowwater mode (about 40 knots (kts)) and an amphibious mode to traverse sand bars and mud flats, providing a “feet dry,” on-thebeach capability.

Eight of the program’s specific capabilities guiding the Phase II industry teams include:

• Un-refueled range, in a no cargo condition, of 2,500 nm in a fuel efficient and good sea-keeping mode (20 kts through Sea State 5). The World Meteorological Organization defines Sea State 5 by wave heights between 2.5-and-4 meters (8.2-to-13 feet (ft)).
  
• Open-ocean operations through Sea State 6 (through Sea State 4 in high-speed/ shallow-water mode) and survivable in Sea State 8.
  
• Maximum speed, full load condition in high speed, shallow-water mode of about 40 kts through top end of Sea State 4.
  
• Amphibious capability, in amphibious mode, to traverse sand bars and mud flats.
  
• Ability to convert between modes at sea without any external assistance.
  
• Maximum un-refueled range in highspeed/ shallow-water mode of about 500-to-600 nm (40 kts through Sea State 4).
  
• Ability to mitigate wave-induced motions in Sea State 4/5 to enable rapid vehicle transfer (loading and unloading) between the T-Craft and an MPF(F)/sealift ship.
  
• To be an assault connector and a logistics connector.

PHASE II TEAMING AGREEMENTS

On May 5, 2008, DoD announced contract awards to three industry consortia that were downselected in November 2007 for Phase II of the project.

Alion Science & Technology Corp., headquartered in McLean, Va., won an approximate $10.2 million cost-plus, fixed-fee completion task order under its earlier contract. The team’s efforts are expected to be completed by April 2010.

The Alion team for Phase II includes CDI Marine, with expertise in high-performance marine vehicles; Raytheon Integrated Defense Systems, with an extensive portfolio in electronics and controls; Nichols Brothers Boat Builders, the potential builder of the demonstrator; and Marintek (Norway) which will perform all of the model testing.

“At the end of Phase II, we will deliver a complete design package that will serve as the basis for the detail design, contraction and demonstration testing of the demonstrator,” Mark Redmond, assistant vice president and manager, ship design management division, Alion, told Military Logistics Forum. “We will also deliver reports documenting all of the development, testing and design work performed during Phase II. There will be a series of models of both the whole vessel craft and portions of the vessel produced during Phase II to assist in the technology development effort, but the actual craft will not be delivered until Phase III,” he emphasized.

A second team, led by Washington, D.C.-based MUMOE Mandal (USA) Inc., was awarded a cost-plus, fixed-fee completion task order valued at about $9.4 million under its previously awarded contract. Work will be performed in the company’s home offices in Mandal, Norway, and work is expected to be completed May 2010. Umoe Mandal is expected to continue its collaboration on T-Craft with Kiewit Offshore Services; General Atomics’ Electromagnetic Systems (EMS) division; the U.S. subsidiary of U.K.-based Griffon Hovercraft; WAMIT; Marintek; Island Engineering and FiReCo.

These companies also bring their own diverse competencies to this consortium. WAMIT provides consulting services for the use of its namesake WAMIT software tools that analyze wave interactions with offshore platforms and other structures or vessels, according to Dr. Chang-Ho Lee, company co-founder.

Another entity, General Atomics EMS, was awarded a two-year, $1.1 million contract to continue developing hybrid electric drive solutions during Phase II. EMS assisted Umoe during Phase I of the effort to develop alternative propulsion schemes based on hybrid electric drive that could replace the traditional mechanical shaft drive designs. “Ed Bowles, chief engineer, EMS, developed several unique designs that provided significant advantages over the mechanical design and eliminated complex gearboxes and difficult, space-consuming shaft alignments. The hybrid electric drive can allow more cargo carrying space, better ship layouts and easier cargo transfer,” read a company document provided by Nancy Hitchcox, marketing communications manager, General Atomics. “Jim Zgliczynski, director of Motors, Generators and Navy Integrated Power Systems said, ‘ONR specifically mentioned the innovative General Atomics hybrid electric drive design as one of the reasons that Umoe was given a high technical evaluation in the selection as one of three competitors to develop the T-Craft in Phase II,’” added the document. During Phase II, General Atomics EMS will complete the preliminary design of the hybrid electric propulsion drive.

New Orleans-based Textron Marine and Land Systems (TM&LS), was awarded an approximate $8.7 million cost-plus, fixed-fee completion task order under its previously awarded contract. Work is expected to be completed by April 2010.

Joining the TM&LS team is CDI Marine (Band Lavis Division); L-3 Communications; Littoral Research Group; MiNO Marine; and Naval Surface Warfare Center, Panama City.

CDI (Band Lavis Division) “is providing contract design support with particular emphasis on computational fluid dynamics for hull, lift fans and waterjet inlet design, as well as stability and motions studies,” remarked David R. Lavis, senior vice president, CDI Marine (Band Lavis Division). ONR, Arlington, Va., is the contracting activity for all three Phase II awards.

THREE DESIGNS

The Alion T-Craft concept is a surface effect ship (SES) that is able to transform into a fully-cushioned vehicle in order to become amphibious. It is approximately 280 ft. (83.5 meters) long-by-80-ft wide.

“The concept’s full load displacement is about 2,000 metric tons. It will have a top speed in excess of 40 kts and carry a minimum of six M1A1 tanks. The major technologies to support the T-Craft mission include: skirt and lift system development, overland propulsion, and the means of transferring cargo vehicles and rolling stock from the ships of the sea base to the T-Craft,” explained Redmond.

The Umoe Mandal-led team is expected to use its Phase I model that is also a hybrid SES and air-cushion vehicle. The team’s allcomposite SES is based on the Norwegian Navy’s Skjold-class fast patrol boat, built by the company. The Skjold is no stranger to the U.S. Navy. The service put the ship through its paces earlier this decade to gain additional insight on ship-based composites and help jump-start the littoral combat ship program.

The Textron team’s “hullform is based on a Textron concept known as a hybrid catamaran air cushion, that can operate as a catamaran at low speeds and in low sea states, and as an SES at high speeds or in high sea states. For the amphibious mode, the craft transforms into an air cushion vehicle (ACV) by deploying side skirts and using an auxiliary air propulsion system,” Jack Giovo, marketing communications specialist, TM&LS, told Military Logistics Forum.

He added, the technology base being applied to the design of the T-Craft “builds upon the 40-plus years of experience in ACVs and SESs at Textron Marine and Land Systems, including the design and construction of the Navy’s Landing Craft Air Cushion, the high speed SES 100B test craft, and the USN SES 200.”

The Textron team is offering innovative solutions to meet the challenge of the two most critical aspects of the T-Craft mission— the transfer of cargo at the sea base and the conversion to a fully amphibious craft at the shoreline.

“A powerful motion control system will extend the sea state for cargo transfer operations well beyond anything that current systems can offer. Equally importantly, the ACV side skirts can be stowed without any impact on the hydrodynamics or structural integrity of the hull in the SES mode,” revealed Giovo.

ENHANCED SHIP-TOSHORE SUPPORT

An autonomous T-Craft would bolster the Navy’s fielded watercraft force that includes the Landing Craft Air Cushion (LCAC)—the workhorse of the amphibious force that provides logistics support throughout an operation’s ship-to-shore movement phases— and landing craft utility (LCU) craft.

The LCAC is a high-speed (over 40-kts), over-the-beach, fully amphibious landing craft, capable of carrying a 60-to-75 ton payload— compared to the venerable LCU that can transport about 170 tons at eight kts.

The LCAC transports the weapons systems, equipment, cargo and personnel of the assault elements of the Marine Air-Ground Task Force from ship to shore and across the beach. LCAC are generally embarked and transported into theater in Navy amphibious ship well decks. The vehicle’s air cushion technology allows the craft to reach more then 70 percent of the world’s coastline.

A service life extension program to extend the LCAC’s hull life from 20-to-30 years for 73 of the 82 active LCACs is being accomplished through fiscal year 2017. TM&LS is the LCAC’s prime contractor.

Compared to LCAC, the T-Craft has the notional requirement to haul a cargo payload of between 300 long tons (lt) (threshold criteria) and 750 lt (objective criteria). T-Craft’s increased maximum capacity would allow it to transport up to ten M1A2 System Enhancement Program-model Abrams tanks (each weighing 69.5 tons) in optimal loading conditions, and four in a minimal loading configuration. This capability compares to one Abrams that its LCAC cousin could transport.

While the conceptual T-Craft has no requirement for fitting into Navy amphibious ship well decks, it is expected to operate with all MPF (F) ships and amphibious ships. Interoperability options with MPF (F) and amphibious ships are expected to include taking rolling stock from a modified large, medium speed, roll-on, roll-off (LMSR) ship, and interfacing with a mobile landing platform (MLP) and other type vessels from the two ship classes. “We’re also looking to ‘fly on’ to the MLP much as an LCAC will be able to fly on to an MLP,” said Cooper. The T-Craft government-industry team also envisions operations from the watercraft’s multiple mooring configurations, including stern-tostern and stern-to-bow.

SPEED AND LARGE LOAD ARE ATTRACTIVE

The two-year, Phase II contracts are structured to allow ONR’s program manager to start receiving some mandated deliverables from the industry teams at 21 months into the contract. “We will begin our technical evaluation at that point,” stated Cooper.

There is expected to be minimal interruption between Phases II and III. “We look for the build phase [Phase III] to be on the order of 36-to-40 months. Delivery would be at that point for demonstration and testing. Part of the deliverables for Phase II includes a plan for Phase III—not only the construction plan but a plan for the disposition of the craft,” remarked Cooper. “The Navy may choose to take ownership [of the T-Craft] at that point, but it may just as well elect not to.”

The T-Craft concept has also caught the attention of at least one defense analyst. Robert Work, vice president, strategic studies, Center for Strategic and Budgetary Assessments, said, “What is attractive about this vessel is its speed and large load. The vessel is as fast as an LCAC, but carries four-to-10 times the weight. It also carries between 1.5- and-four times as much as the Landing Craft Utility, but at nearly four times the speed.” As Work points out, “This will increase the velocity and throughput of a wide variety of things moving from a sea base to over the shore, including vehicles, equipment, fuel and water, break-bulk cargo and possibly people.”

While there is no current ONR-mandated capability for T-Craft to embark passengers for long voyages, this is an option that is being examined by at least one Phase II industry team.

In order to perform as an assault connector as stated in the ONR BAA, all T-Craft would have to be able to carry the crews of embarked vehicles. As a result, “Another thing this [T-Craft] would be very good for would be distributed insertions of small armored units across a wide front. The T-Craft can insert platoon-sized, mechanized elements over a large part of any coast. If faced with an enemy armed with a lot of guided weapons, or if operating under a nuclear threat, distributed insertions would be absolutely critical for survivability reasons. So, the T-Craft looks attractive as both a logistical craft to increase throughput of equipment, people or breakbulk supplies in ship-to-shore operations, and as a means for distributed sea based maneuver,” concluded Work. ♦