2.704

Projects in Naval Ship Conversion Design

IAP 2012

LSD 41 to CVU Conversion

LT Carl BodinLT Katie Gerhard

LTJG Kostas Nestoras

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Unmanned Vehicles: A new type of Soldier, Sailor, and Marine

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On Land

At Sea

In the Air

The vision…

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Sponsors

• We would like to thank the following people who sponsored this project and assisted the team:– Mr. Jeffrey Smith, Director of Future Ship and

Force Architecture Concepts, Division NAVSEA 05D

– Mr. Steven Wynn, NAVSEA 05D

Problem Statement: “Convert an LSD to angled flight deck UAV and USV carrier”

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UAV Options

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High: Example: Global HawkWingspan: 116 feetPayload: 4400 lbs.

Medium: Example: MQ-9 ReaperWingspan: 66 feetPayload: 3800 lbs

Low: Example: Scan EagleWingspan: 10 feetPayload: 11 lbs

USV Options

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High: Example: ShadowLength: 39 feetPayload: 5000 lbs.

Medium: Example: Spartan ScoutLength: 36 feetPayload: 3000 lbs.

Low: Example: StingrayLength: 12 feetPayload: 300 lbs.

Launching System

• Three variants: – EMALS– Steam Catapult– None/mobile units

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Configuration of the Flight Deck

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• Straight runway• Angled runway• Two runways• Ski jump option

Other Design Parameters

• Ship’s (Max) Speed– Low: 20 kts– Medium: 25 kts– High: 30 kts

• Ship’s Motion– Fin Stabilizers– No assistance

• Number of UAV/USV– High, Medium, Low

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Design Philosophy

Convert the LSD 41 into a CVU (Unmanned Aerial and Surface Vehicle Carrier)

• Emphasizing UAV capabilities over USV• Maximizing performance for the lowest cost• Accepting higher risk to gain new capability

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Decision Framework

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#12 #2

#16

Design Parameters

Initial Number of options

Final Number of options

UAV Capability 3 2Number of UAVs 3 2Configuration of

Flight Deck 6 2

Catapult System 3 1Ship's Motion

Control 2 1

Ship's Speed 3 2USV Capability 3 2

Number of USVs 3 2

• Weighted Sum and AHP decreased variant combinations from 8748 to 64 and then to the final variant • Team member experience and sponsor (weighted) inputs

Variant USV Capability USV Number

# 2 Medium Medium

# 12 Medium Low

# 16 Low Low

• Final Variant: UAV Capability Medium USV Number Low

UAV Number Medium Ship Speed Medium

Flight Deck Angled Catapult System EMALS

USV Capability Medium Ship's Motions Control Fin Stabilizers

Topside View

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RAM

Ku-band SATCOM

CIWS

CIWS

Ku-band SATCOMUAV Elevator

UAV ramp

Stack

Stack

Runway

Arresting Wires

UAV

EMALS

RAM

Internal Arrangement

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USV Bay/ Well Deck

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New SSDG Location

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Stability

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Ship KG GMt Draft

CVU 31.97 12.52 17.99

LSD 37.2 8.1 19.5

- CVU has lower KG and higher GM, making it more stable- Within the roll period of DDG 51 and CVN

LSD 41 Hull

CVU Seakeeping

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Overall Stability Profiles (Full Load)

NO

ski

jum

p

Sea State 4 Sea State 5

WIT

H s

ki ju

mp

Sea State Wave Characteristic Height [m (ft)]

4 2.26 (7.41)5 3.53 (11.58)6 6.16 (20.21)

Conditions selected were the worst identified in each sea state

• Assessment based on STANAG 4154• Analysis made with MAXSURF suite• Ski Jump enhanced the operability of

CVU and increased her flight operations envelope

• Full flight operation can be conducted up to SS5

• At SS6 only launch operations can be conducted

• Effects of fin stabilizers not considered

Strength

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- Stress meets all requirements in the DDS-100-1 (<8.5 LT/in2 for a combatant) - Hangar bay deck considered in strength calculations

Cost Estimation

• Modified 2N Cost Model – Weight Based Cost estimation– Sponsors provided CERs

• Base conversion cost calculated, GFE added in separately

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• Cost Estimations– Base conversion: $95M (FY11$)– GFE cost: $159M (FY11$) for 19

consoles– Total: $254 (FY11$)

Summary

• Team & Sponsor Goals met– Enhanced UAV capability– Angled flight deck– Room for future growth– Met 2N Convergence criteria

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CVU Characteristics Value UnitsLength Overall 610 ftBeam 84 ftDraft (Full Load) 17.6 ftInstalled Power 6500 kWLight Ship Displacement 11,041 LTFull Load Displacement 14,255 LTSustained Speed 23 ktsMaximum Speed 25 ktsEndurance 18 ktsNumber of UAV 20Type of UAV MQ‐9 ReaperNumber of USV 9Type of USV Spartan ScoutCP 0.604CB 0.571CX 0.946