Military


Sea Base Connector Transformable-Craft (T-CRAFT)
Sea Base Connector Test Craft (T-CRAFT)
Beachable High Speed Sea Base Connector

There is a need for high speed marine vehicles that are beachable to allow discharge of troops and cargo. One of the primary military purposes of beachable marine vehicles is to transport cargo such as vehicles and troops from ships at sea to beachheads. These beachable marine vehicles also have commercial application where they may transport cargo to unimproved beach areas.

The anticipated goal of a future T-Craft program would be to contract for the design, production and demonstration testing of a large-scale prototype. In August 2005 the Office of Naval Research solicited proposals through Broad Agency Announcement (BAA) 05-020 for a prototype demonstrator of a Transformable-Craft (T-CRAFT) which can deploy in an unloaded condition (range of 2,500 nm) from the intermediate support base to the Seabase and then be used as a Sea Base connector, transporting wheeled and tracked vehicles through the surf zone and onto the beach.

ONR desires to have the craft run at high speeds in as shallow water as realistically possible. ONR understands that depending upon hullform and propulsion system chosen, this minimum water depth will vary concept to concept. ONR envisions this minimum water depth to be somewhere between 6 and 14 feet.

The sand bars and mud flats could be submerged under a small amount of water or could be completely exposed during peak low tide. The intent is for the craft to be able to traverse these obstacles such that it could land "feet dry" on the beach. Our vision of "feet dry" is that the craft is on firm ground, sufficiently above the high water line so that the equipment can be off-loaded without the likelihood of getting stuck in soft sand/mud/etc. If the use of a detachable portion of the craft or an intermediate craft met all of the intended capability criteria, that would be acceptable.

The amphibious capability is to get the craft "feet dry" on firm ground. We envision this as sufficiently above the high water line so that the equipment can be off-loaded without the likelihood of getting stuck in soft sand/mud/etc. The sand bars and mud flats could be submerged under a small amount of water or could be completely exposed during peak low tide. The intent is for the craft to be able to traverse these obstacles such that it could land "feet dry" on the beach. It is not envisioned that the craft would require inland amphibious operational capability beyond the "feet dry" requirement.

No threshold or objective targets have been established for either the speed of advancement or the distance over the sand bars and mud flats. The ability to traverse these quickly is desirable from the perspective of both throughput and safety as the craft would be more vulnerable at slower speeds. However, we do not desire to give specific targets as we are looking for innovative solutions to what we believe to be the most challenging aspect of this concept. The vision of Seabasing is to be able to operate from the sea virtually anywhere in the world. Many of the coastal areas have swamps, sand bars, mud flats, etc. that an assault craft and/or logistics craft would have to be able to traverse to get to shore. The distance required to travel over these to be able to get "feet dry" on firm ground could also vary greatly.

ONR defined "feet dry" as sufficiently above the high water line so that the equipment can be off-loaded without the likelihood of getting stuck in soft sand/mud/etc. The sand bars and mud flats could be submerged under a small amount of water or could be completely exposed during peak low tide. Therefore the soil characteristics would vary greatly as well.

As this is an Innovative Prototype to prove a game changing concept vice an acquisition program, no absolute requirements were given for deck loading beyond the payload requirements provided in the BAA. However, it would be expected that the vehicle pressure load limits would be similar to the current LCAC which is no greater than 80 psi. The M1A2 can be assumed to be the heaviest vehicle to be transported for the purposes of demonstrating this prototype.

Vehicles capable of both land and water operation, also called "amphibious" vehicles, are known. Previous attempts to construct amphibious vehicles have encountered many problems. The prior art vehicles are mainly hull based-created by adding a hull to a land-based automotive type vehicle, or adding automotive features to a hull-based boat. The disadvantages of this type of vehicle are many. For example, many of the previous vehicles were overweight, using heavy steel for the hull sections. Many were unstable, due to a high center of gravity created by the hull. Many of the previous vehicles required extensive complicated machinery, such as separate motors for the land and water based travel, and were not capable of achieving high speeds in water due to a large amount of drag created by the design of the hull and wheels. In addition, hulled vehicles require the addition of costly and complex ventilation equipment to remove dangerous contained engine fumes.

The US Navy has workhorse vessels for this purpose such as the LCU (Landing Craft Utility) and related marine vehicles. The LCU is an almost flat bottomed monohull which is necessary so that it can drive on and off of beachheads; however, this design makes the LCU and its brethren very uncomfortable in rough seas. A further and most significant shortcoming of the LCU is that it has limited speed capabilities. In the cast of the LCU, the loaded top speed is only 9-12 knots.

A more recent development than the LCU is the LCAC (Landing Craft Air Cushion). The LCAC is a SES (Surface Effect Ship), also known as a hovercraft, with a pressurized air cushion that supports the full vehicle weight. The LCAC has a flat cargo deck with a blower pressurized air cushion underneath that is surrounded by 360 degrees of flexible skirts or seals. As such, the LCAC can run up onto beaches with limited slopes and is therefore fully amphibious. The LCAC has speed capabilities in the 45 knot area but has very limited rough sea capabilities. Further, the gas turbine powered LCAC is very expensive to start with, has a high fuel burn rate, and its flexible full perimeter skirts are high maintenance and expensive to replace.

There is also the recently developed Marine AAAV (Armored Amphibious Assault Vehicle). This is basically a small tank that is designed to also operate in a water environment. It requires a tremendous amount of propulsive power when waterborne since its tank tracks are in water contact at all speeds hence giving the AAAV a very high water drag component. Top speed waterborne is only about 25 knots. Also, due to its rather boxy tank-like shape and heavy weight, it is not capable of operating in heavy seas.

The limitations of current landing craft designs, such as the design concepts incorporated into the LCU or the LCAC, make them inappropriate for the Army TSV (Theater Support Vessel), the Navy and Marine Corps Sea Basing program HSC (High Speed Connector), the Navy Fleet Readiness and Logistics Office, and Naval Sea Systems Command (NAVSEA) RSLS (Rapid Strategic Lift Ship), or the Navy LCS (Littoral Combat Ship). The TSV must transit oceans on occasion so a rather large high speed and seaworthy vessel is required. The Army has tested existing commercial passenger/vehicle catamaran ferries for the TSV program and they do show some promise but are not beachable due to deep draft requirements.

The Navy/Marine Sea Basing program has pointed out the need for beachable high speed marine transports that are referred to as HSCs (High Speed Connectors). The concept behind Sea Basing is to have large supply ships positioned about 200 miles offshore with troops, supplies, vehicles, etc. transported to beachheads by the HSCs. In the case of the Sea Basing program large parent ships are stationed 100 to 200 miles offshore so a HSC design that offers high speed and beachability to run between these parent ships and beachheads is demanded. There are a number of HSC sizes required with the smallest being about 170.times.50 feet and capable of transporting over 200 tons of cargo at 40 knots or more.

No organic accommodations will be required on the prototype or the production vessels. For longer transits bidders should consider alternative approaches to meeting habitability requirements. The crew size of 2 Objective and 3 Threshold is the entire complement for the Sea Base to Shore mission, when the craft is being used to deliver vehicles/equipment to the beach from the Sea Base. For this operation assume the Sea Base is between 25 and 100nm from the shore. The government expects that when the craft transits longer distances that surge crew members will be embarked to stand the additional watches.

The expected Technology Readiness Level (TRL) of the overall prototype is a 7. If the submitter wishes to propose a high risk technology for the craft, then the proposal should include the plan and cost for a risk demonstration which fits within the overall schedule and cost for the program.

The Office of Naval Research has identified the following list of capabilities, the desired thresholds/objectives, and a list of other relevant information for the T-CRAFT prototype.

Capability List

1. Un-refueled range, in a no cargo condition, of 2,500 nautical miles in a Fuel Efficient/ Good Sea Keeping Mode (20 knots, through Sea State 5)

2. Open ocean operations through Sea State 6 (through Sea State 4 in High Speed/Shallow Water Mode) and survivable in Sea State 8.

3. Maximum Speed, full load condition in High Speed, Shallow Water Mode = ~40 knots through top end of Sea State 4.

4. Amphibious capability, in Amphibious Mode, to traverse sand bars and mud flats thereby providing a "feet dry on the beach" capability.

5. Ability to convert between modes at-sea without any external assistance.

6. Maximum un-refueled range in High Speed/Shallow Water Mode = ~500-600 nautical miles (40 knots, through Sea State 4).

7. Ability to mitigate wave-induced motions in Sea State 4/5 to enable rapid vehicle transfer (loading/un-loading) between the T-CRAFT and a Maritime Prepositioning Force (Future)/Sealift ship.

8. To be used as an assault connector and a logistics connector.

Other relevant information

1. No habitability/living spaces required.

2. Prototype will not be classed (ABS, DNV, etc.), however potential follow-on craft may be required to be classed.

3. No requirement to fit into Navy Amphibious Ship Well Decks (L-Class ships).

4. On board fire-fighting capability should be automated to the maximum extent possible to meet the desired crew size.

5. No stealth or signatures requirement.

6. No organic capabilities required to handle pallets, quad-cons, or 20ft containers.

Notional RequirementsThresholdObjectives
Cargo Payload Weight300 lt750 lt
Cargo Payload Area2,200 sqft5,500 sqft
Crew Size32
Beach Slope Climbing0.5%2%
Vehicle Ramp Angle15.0 degrees12.5 degrees
Vehicle Deck Loading350 psf550 psf

The Office of Naval Research (ONR 33) envisions a three phase program. It is anticipated that the first phase of the program would consist of multiple awards for craft preliminary designs which show the technologies to be included in the prototype to meet the 2 desired capabilities. Phase I is anticipated to last for 9 months and each Phase I award is estimated to be valued at $1M to $2M. The government anticipates to then down select the two most promising concepts and award a second phase to develop detailed designs to be model tested, head-to-head in the appropriate facility. Phase II is anticipated to last for 1 year and each Phase II award is estimated to be valued at $4M to $6M.

It is ONR's vision to test the models side by side at the same facility. If for some unforeseen reason, they can not be tested at the same time in the same facility, then they will be tested under the same or as similar conditions as possible so that a fair and genuine comparison can be made. The prototypes are to be designed to operate in the same environment at full scale, but if one model's design had some specific requirements which required testing facilities that were incompatible with the other model, then ONR would allow separate facilities to be used while keeping as much in common during the testing as possible.

The government required detailed cost proposals for all three phases under this solicitation. However, the cost proposals for Phase III will be required as one of the deliverables of Phase II. Using the Phase III proposal and the results from the model tests and previous phases, the government may then down select for a single Phase III award to design, build, and test the prototype demonstrator. Phase III is anticipated to have a period of performance of 4 years and a cost of less than $150M. As part of the Phase I and Phase II design processes, the government will require the awardees to demonstrate/calculate how the prototype could be scaled up from the government's threshold requirements to the objective requirements.

The due date for receipt of Full Proposals was initially set as 2:00 p.m. (EDT) on 30 September 2005. It was initially anticipated that final selections would be made by 31 December 2005. As soon as the final proposal evaluation process is completed, the Offeror will be notified via email or letter of its selection or non-selection for an award. Proposals exceeding the page limit may not be evaluated.

Under Amendment 03 (Posted on Dec 15, 2005), full proposals were due on 03 January 2006. Notification of Selection for Award will be approximately 3 Apr 06. It was anticipated that the contract would be awarded by 03 July 2006. Due to the extension of the proposal due date to 3 January 2006, the likely date of any resulting Phase I award would not be until May/June of 2006. Phase I is anticipated to last for approximately 9 months, Phase II would begin shortly after the completion of Phase I and is anticipated to last approximately 1 year. Phase III would begin at the completion of Phase II and is anticipated to last approximately 4 years.

The T-Craft BAA requests submitting parties to address prototype disposal as a separate cost item, independent of Phase I, II, and III efforts. The intent of this statement was to ensure that all costs will be captured. As this is a Science and Technology Demonstrator and not an Acquisition Program, there is no follow on funding to support operations and maintenance of the prototype after testing and evaluation are complete. The Offeror's proposal should include a recommended disposition of the prototype after testing along with any of the associated costs. This may or may not include actual disposal of the craft.



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