JJMA ocean briefing 2april04

OCEAN Class AGOR Concept Definition Task: 

OCEAN Class AGOR Concept Definition Task Interim Review 2 April 2004

Slide2: 

Concept Design Capabilities Bold Text Indicates SMR

Slide3: 

Concept Design Capabilities Bold Text Indicates SMR

Slide4: 

Concept Design Capabilities Bold Text Indicates SMR

Concept Design Process: 

Concept Design Process Develop 3 Desired (objective) ship concepts that meets the desired SMRs Monohull SWATH X-Craft Variant Determine changes to designs to meet minimum SMRs Determine feasibility of $50M cost cap

Slide6: 

Lay out required spaces to determine length and beam requirements Optimize hull form coefficients for seakeeping and powering (SKOPT) Develop hull lines in FASTSHIP Develop concept level arrgts in AutoCAD Calculate EHP, DHP & propulsive coefficients (Holtrop & Mennen Regression) Select Machinery and lay out machy arrgts based on high level EPLA Endurance Fuel Calc. Size structural scantlings using ABS rules Weight estimate ratioed from existing ships and modified by inserted weights Seakeeping analysis with SMP (ship motions tool developed by Navy) Concept Design Process Repeat as necessary

Desired Monohull Concept: 

Concept Design Variants Desired Monohull Concept

MAIN DECK & 1ST PLATFORM: 

Concept Design Variants MAIN DECK & 1ST PLATFORM

01 & 02 DECK: 

Concept Design Variants 01 & 02 DECK

Powering Estimates: 

Propulsion - Monohull Powering Estimates

Slide11: 

Propulsion - Monohull Main Propulsion System Integrated Diesel Electric System 3 x 1195 bkW, Caterpillar 3516 Propulsion Gensets 3 Caterpillar 3412C Ship Service Gensets 2 x 350 ekW, 50 Hz @ 1500 rpm for 700 ekW + standby Propulsion Motor and Propeller Unit 2 x 1500 kw, 1000 rpm DC motors 2 x steerable fixed pitch Z-drive. 2 x 2850 max kW @ 1000 rpm. Propeller diameter = 11.5 feet. Dynamic Positioning System Bow Thruster 1 x Elliott White Gill T3S-40, 686 kW

Mission Fuel Load Estimates: 

Propulsion - Monohull Mission Fuel Load Estimates Transit, 20 Days @ 12 Knots & 20 Days on Station 375 LT of Fuel Survey, 30 Days @ 12 Knots 410 LT of Fuel Transit, 10800 nm @ 11 Knots 395 LT of Fuel

Slide13: 

Seakeeping - Table of Operabilities

Transit, MID SS4, Tm=9s: 

Transit, MID SS4, Tm=9s Long-Crested Seas Short-Crested Seas Seakeeping - Effect of Anti Roll Tank on Monohull Motions Shaded Areas Exceed Motion Criteria With Anti Roll Tank Without Anti Roll Tank

Transit, MID SS5, Tm=9s: 

Transit, MID SS5, Tm=9s Long-Crested Seas Short-Crested Seas Seakeeping - Effect of Anti Roll Tank on Monohull Motions Shaded Areas Exceed Motion Criteria With Anti Roll Tank Without Anti Roll Tank

Transit, MID SS6, Tm=13s: 

Transit, MID SS6, Tm=13s Long-Crested Seas Short-Crested Seas Seakeeping - Effect of Anti Roll Tank on Monohull Motions Shaded Areas Exceed Motion Criteria With Anti Roll Tank Without Anti Roll Tank

Slide17: 

Concept Design Variants X-Craft

X-CRAFT: 

X-CRAFT Main Characteristics ONR X-Craft X-Craft AGOR Length Waterline, ft 240 240 Beam, Overall, ft 72 72 Beam, Waterline, ft 16.6 20.5 Draft, ft 11.8 14.6 Displacement, Lton 1400 2150 Speed, knots >50 12 Propulsion Gas Turbines & Diesels Diesel Electric, Integrated 2 x 25 MW, 2 x 4 MW 6 x Caterpillar 3412C Range 4,000 nm @20 knots 10,800 nm @12 knots Payload, Lton 150 200 Crew 25 18 + 25 Scientists SHP 72,000hp@50 knots 2,800hp@12 knots Working Deck Area 2,050 sq. ft Lab Area 2,108 sq. ft

X-CRAFT: 

X-CRAFT AGOR Variant Displacement Based on the Ocean AGOR SMR, the UNOLS X-Craft is estimated to have a displacement of 2,150 Lton, compared to the 1,400 Lton ONR X-Craft. To gain the required additional displacement, one option is to linearly scale two side hull cross sections under wetdeck and keep the ship length and hull above wetdeck unchanged. General Arrangement The mission bay deck of the ONR X-Craft will be the main deck of the UNOLS X-Craft. Remove the heavy flight deck of the ONR X-Craft. Add an 01 deck over the main deck. More than enough space available based on the existing main dimensions. Therefore, the length and beam of the ONR X-Craft were kept unchanged. Hull Form No change of the ship length. Geosim in the body section under the main wet deck with a linear ratio of 1.239.

X-CRAFT: 

X-CRAFT AGOR Variant Since the operation speeds are significantly lower, it is believed that at least the stern shape needs to be changed to optimize the low speed resistance of the Ocean AGOR. Structures Aluminum structure. The hull shall be designed to ABS 90 meter Rules or SWATH Guide. Design speed difference will change scantlings. The deck structures will be designed according to the SMR loading requirements. Current Flight Deck shall be replaced by a much lighter deck structure. Propulsion System The gas turbines shall be removed The gear diesel prime movers will be replaced by integrated diesel-electric systems. There is no need for 4 waterjets for the much lower speed requirement. Two water jets may be installed instead. Low speed water jets should be investigated to provide higher propulsion efficiency at 12 knots, such as the Traktor Jet. The current KaMeWa high speed water jet performs poorly at low speeds. Traditional propeller could be an optional propulsor with a higher efficiency.

X-CRAFT: 

X-CRAFT Main & 01 Deck

X-CRAFT: 

X-CRAFT AGOR Variant Profile X-Craft Profile

Slide23: 

Propulsion – X-Craft Resistance and Fuel Consumption

X-CRAFT: 

X-CRAFT Discussions of the AGOR X-Craft Variant Hull Form Current hull form is for high speed and high propulsion power design. Modification to the hull form may yield better performance at lower speed. Stern shape change to accommodate the propulsion method change. Propulsion System Availability of low speed waterjet. Most of the waterjets today are designed to operate at high speeds (>30 knots) and have low propulsive efficiencies (<0.45) at low speeds (<20 knots). Traktor Jet has large impeller diameter low speed water jets with higher efficiency (~ 0.5). But the model that can produce the required thrust is still in the prototype stage. Shafted propeller with rake is an option. Propeller and required clearance need to be verified. Propeller efficiency typically 0.6 or better. Z-drive. The unit is usually much heavier than a water jet or a shaft propeller. SWATH type stern with propellers at the end of the tail cones.

Slide25: 

Work Remaining Incorporate Comments Refine X-Craft Concept Designs & Analysis Develop SWATH AGOR Concepts Size Minimum SMR Concepts Investigate Technologies Portable Lab Vans Overside Handling Bubble Sweepdown