oct 2 2 2014 unclassified frc::>m: commanding …icefloe.net/files/wagb20_healy.pdf · document...

DEPARTMENT OF THE NAVY NAVAL SU R~FACE WARFARE C ENTE R

C A RDEROCK DIVIS ION

9 5 00 MAICA R T H U R B OU L E VAR D

W E ST BETH ESDA, MD 208 17-5700

9094

I N REP L Y REFER T O :

Ser 7100/228/2014

OCT 2 2 2014 UNCLASSIFIED

Frc::>m: Commanding Officer, Nava.l Surface Warfare center, Carderock Division·

To : Distribution

Subj: FORWARDING OF TECHNICAL REPORT

Enc:l: NSWCCD-71-TR- -2014/592 October 2014 "Acoustic Trial Results for United State!S Coast Guard cutter HEALY (WAGB -2 0)" (ACTRL 09/14)

1 . On 3 September 2014 , the underwater radi ated noise leV«:!ls for Un:ited States Coast Guard cutter Healy (WAGB-20) were measured at the U.s. Navy • s Southeast A.laska Acoust i c Measurement Fac:il i ty near Ketchikan,Alaska . The overall objective of t:his test was to quantify the underwater noise levels of Healy and compar e the level s to ships that operate in the same arctic re9ion .

2. Enclosure (1) is forwarded as electronic distribution.

R. D. KOLLARS By direction

9094 Ser 7100/228/2014

UNCLASSIFIED Subj: FORWARDING OF TECHNICAL REPORT Electronic Copy to: USCGC HEALY CO e-mail address: [email protected] USCG (David Forcucci) e-mail address: [email protected] COMNAVSEASYSCOM WASHINGTON DC (SEA 05P1 M. Martin) e-mail address: [email protected] NAVSURFWARCEN SHIPSYSENGSTA PHILADELPHIA PA (A. Boughner) e-mail address: [email protected]

NA.VAL SURFACE WARFARE CE:NTER Carderock Division West Bethesda, MD 20817-5700

NSWCCD-71-TR--2014/592 October 2014

Signatures Department Technical Report

Acoustic Trial Results for United States Coast Guard Cutter HEALY (WAGB-20) (ACTRL 09/14)

by Chelsea H. Valadez

Distribution Statement D: Distribution authorized to U.S. Government agencies and their contractors only for administrative and operational use. Other requests for this document will be referred to NSWC, Carderock Division, Bethesda, MD.

DESTRUCTION NOTICE: For unclassified, limited distribution documents, destroy by any method that would prevent disclosure of contents or reconstruction of the document

THIS PAGE INTENTIONALLY LEFT BLANK

NSWC 5602124 (REV 3-13)

NAVAL SURFACE WAR~FARE CENTER Carderock Division

West Bethesda, MD 20817-5700

NSWCCD-71 -TR--20141'592 October 2014

Signatures Department Technical Report

Acoustic Trial Results for United States c:oast Guard Cutter HEALY (WAGB-20) (AICTRL 09/14)

by Chelsea H Valadez

DistribUition Statement D: Distribution authorized to U.S. Government agencies and their contractors only for administrative and opmational use. Other requests for this doc:ument will be referred to NSWC, Carderock Division, Bethesdla, MD.

DESTRUCTION NOTICE: For classified, limitecl distribution documemts, destroy by any method that would prevent disclosure of contents or reconstruction of the document.

THIS PAGE INTENTIONALLY LEFT BLANK

NSWC 5602/24 (REV 3-13)

Acoustic Trial Results for United States Coast Guard Cutter HEALY (WAGB·-20) (ACTRL 09114)

TABLE OF CONTENTS

ADMINISTRATIVE INFORMATION. ........................ ..... ... ............... ...... 1v

E:XECUTIVE SUMMARY....... ........ . ...... ... ....... ........ ... .. .. .. ... ... ... ... .. ...... 1 lNTRODUCTION... ... ....... ............. ..... ... .. ........... ... .... ....... ...... ............. 1 SHIP CHARACTERISTICS......... ... ..... .. ... ................................................ 2 l'EST METHODS.... ... ..... ... ... ..... . ........... ...... . .. .. ... ...... .......... .. .. .. ......... 3

DISCUSSION OF NOISE SPECTRUM. ... ... . .......... . ............... . .... ... ......... 4 llESULTS...... .... ...... ...... . .......... ... ... .. . ......................... ... . .................... 4

BASELfNES.. . . . . ... ........ .. .. ..... ... ... .... . .. . . ... .... ... . ..... ... ........................... 4 DIAGNOSTIC TESTS .... . ... . ................... . .. . ... . ... .. ......... . ................... .. 5

Rudder Evaluations ........ .. ..................... . ........ . ... . ..................... _... 5 Full Backing Bell . . . . . . . . . . . .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .... .. .. .. ..... 6 Full Twist . . ..... . .............. .. ............. . .... . ...... . ... . .... . .. . .............. .... .... . "Steam" Hammer ........... .. .... . ......... ... ..... . ....... . . . ..... . ................... ..

DIESEL-ELECTRIC SHIP COMPARISON .. . ...... . . . . . ....... . ... . ... . ...... . .. . . .. .

6 6 6

SUMMARY AND CONCLUSIONS....... . .. . ..... .. ...... ... .... . ............ .. . . .... . ..... 7 FIGURES .... .. .... .. ............. . ..... ... .. .... . ........................ . ... .. .... ................. 8 F~FERENCES. . ..... .. . . . . . . . .. . . . . . . ... . . . .. . . . . . . . . .. . . . . . . . . . . ... . .. . .. . . . .. . ... . . . . . . . . . . . .... 15

TAJ~LES

Table 1 -USCG Healy (W AGB-20) Ship''s Characteristics............................ . ... 2 Table 2 - USCG Healy (W AGB-20) Evaluated Tests............... . ....... .. .. . ...... . ... . 3

FIGURES

Figure 1- Southeast Alaska Acoustic Measurement Facility....... . . . . . ... . ......... . .... . 8 Figure 2- Beam Aspect for Noise Measurement....................... .. .............. .. .... 9 Figure 3 -Healy Overall Sound Levels by Speed ................ .. ...... . ............. .. _.... 10 Figure 4 - Healy Overall Sound Level Compared to Similar Diesel-Electric Ships....... 11 Figure 5 - Healy Overall Sound Level Compared to Similar Diesel-Electric Ships,

12 Alternate Speed .... . ... . .. . ... . .... . ..... . ................... . .... . ............... . . . .. . Figure 6 - Healy vs Relevant Diesel-Electric Ship Overall Sound Levels by Speed

13 and Range ..... . ... . ... .. .. . ... . ...... . .. ... .. .. .. . ... . ........ . ...... . ....... . ... . . . ... . . Figure 7 - Healy Compared to Diesel-Electric Ship' s Max and Min Overall Sound

Levels at Range and Speed .... . ..... . ... . ... . .......... . ..... . . . .. .............. .... .. ... .. .. 14

iii

Acoustic Trial Results for United States Coast Guard Cutter HEALY (WAGB-20) (ACTRL 09/ 14)

ADMJNISTIU~TIVE INFORMATION

Naval Surface Warfare Center Carderock Division, Signatures Department was tasked by

the United States Coast Guard (USCG) to evaluate the underwater radiated noise signature of USCG Cutter Healy at the Southeast Alaska Acoustic Measurement Facility (SEAF A C) in Ketchikan, Alaska on 3 September 2014. The objective of the test was to provide better insight

to how an ice breaker compares to other ships that operate in the same Arctic region. The data

acquired from this test will also aid the Coast Guard's development of Healy 's Environmental

Impact Statement (EfS) for ongoing operations conducted in the Arctic. The Coast Guard point

of contact for the test was Dave Forcucci. The funding document for the test was provided via MIPR CG3514XJCE016.

iv


EXECUTIVE SUMMARY

On 3 September 2014, the underwater radiated noise levels for United States

Coast Guard Cutter Healy (WAGB-20) were measured at the US. Navy 's

Southeast Alaska Acoustic Measurement Facility near Ketchikan, Alaska. Ti"ze

overall objective of this test was to quantify the underwater noise levels of Healy

and compare the levels to ships that operate in the same arctic region. Due to the

classification of Healy 's underwater radiated signature this report will only

represent that signature as an overall sound level.

Healy was evaluated at the following ~peeds: 4.6, 8, II and I6 knots. Comparisons throughout this document were made by using the overall sound

level. The overall sound level speeds rangedfrom I 59 to I82 dB reI p.Pa at 1

yard. The overall sound level increased with speed from 4. 6 to I6 knots.

Five and I 0° rudder swing tests were conducted at 4. 6 and 8 knots,

respectively. Rudder swing overall sound levels were similar to the baseline levels at same speeds. While transient noise was present following each rudder

swing the long term average of the data presented smeared out the transient level

as if it wasn't there. Conducting transient analysis would showcase the rudder

swing transient characteristic and lE?vel.

A full backing bell diagnostic/rom 8 knots was conducted to determine the

maximum noise level as a result of the evolution. The maximum overall sound level from a backing bell maneuver was 19 5 dB.

A .full twist evaluation was conducted with the port shaft operating aft at 60

rpm and the starboard shaft operating forward at 58 rpm. The maximum overall

sound for this evolution was 183 dB.

A diagnostic test secured the steam to the oil tanh at 4. 6 knots. There was no

measurable difference between the overall sound level of this test and the baseline level.

Ship comparisons were made using the overall sound levelsfromfour other 1 diesel-electric ships. Healy 's level was 5 dB Lower than the quietest diesel

electric ship at II knots. At 16 knots Healy had the highest level of the ships

compared.

INTRODUCTION

On 3 September 2014, United States Coast Guard Cutter Healy (W AGB-20) had its

underwater radiated noise levels measured. Healy is one of the largest non-nuclear ice breakers

1 All dB= dB re 1 ~Pa @ 1 yard unless stated otherwise

1


in the world and one of 50 ships able to conduct missions in the Arctic region. Icebreakers are designed to operate in ice-covered waters with a strengthened hull, an ice-clearing shape, and the propulsion power to push through consolidated ice. Cutters are also used for surveying,

oceanographic research, vessel escort in ice, salvage, pollution response, environmental protection, enforcement of laws and treaties, and search and rescue.

The noise measurements were conducted at the Southeast Alaska Acoustic Measurement

Facility (SEAF A C). The objective of this test was to quantify the underwater noise levels

ass:ociated with the ice breaker as compared to other ships that operate in the same Arctic region.

SEAFAC was established by the U.S . Navy near Ketchikan, Alaska to measure underwater noise

signatures of ships and submarines. A picture of the operating space is presented in Figure I.

SIDP CHARACTERISTICS

Healy is the Coast Guard's 420-foot icebreaker constructed by Avondale Shipyard in New Orleans, Louisiana, and launched Nov·ember 1997. Healy's primary mission is to function

as a high latitude research platform. All ships systems are designed to function for extended

winter operations in these areas including intentional wintering over. Healy has fully automated

systems for control of the ship and the machinery plant.

Healy is powered by a diesel-electric propulsion system. Four diesel engine driven generators provide all electrical service to the ship, including power to the electric main

propulsion motors. The ship is equipped with a cycloconverter to convert constant frequency

AC electrical power from the generators to variable frequency AC power to drive the:: electric propulsion motors. Other relevant Healy specifications are listed in Table I.

Table 1 - USCGC Healy (WAGB-20) Ship's Characteristics

Lemgth, Overall 420'0" (128 meters) Beam, Maximum 82'0" (25 meters)

Draft, Full Load 29'3" (8.9 meters.)

Displacement, Full Load 16,000 LT

Propulsion Diesel-Electric, AC/AC Cycloconvertor

G1enerating Plant 4 Sultzer 12Z AU140S

Shaft Horsepower 30,000 Max HP

Propellers 2 Fixed Pitch, 4 Bladed

Auxiliary Generator EMD 16-645F7B, 2400kW

Fuel Capacity 1,220,915 GAL (4,621 ,000 liters)

Cruising Speed 12 knots@ 105 RPM

Max Speed 17 knots@ 147 RPM

lcebreaking Capability 4.5 ft@ 3 knots (continuous)

Science Labs Main, Bio-Chemical, Electronics, Meteorological, Photography

Accommodations 19 Officer, 12 CPO, 54 Enlisted, 35 Scientists, 15 Surge, 2 Visitors

2


Healy was evaluated at four speeds: 4.6, 8, 11 and 16 knots. Ship speed over ground was established by SEAFAC's Automated Information System (AIS) tracking system. Table 2 lists the: speeds tested, propulsion rpm, and comments associated with each run. Noise signatures were established for constant rpm operating in a straight-line condition. In addition to the baseline signatures, the following diagnosti•:: tests were conducted: steam secured to oily tanks, 5 and 10° rudder turns, a full backing bell from 8 knots, and a full twist operation. Bow thrusters

were not operational and not evaluated.

Table 2- USCGC HEALY (WAGB-20) Radiated Noise Run Plan

Test ID Ship Ship Shaft rpm CPA Comments

1SA 4.6 s 40 512 Data No Good, Small boat interference

2PA 4.6 N 40 409

1SB 4.6 s 40 409 No data, Acquisition Error

7PA 4.6 N 40 589 Steam Secured and s ±5° Hudder Turns

1SC 4.6 s 40 647

3PA 8.0 N 58 520

4SA 8.0 s 58 553

5PA 11.4 N 87 476

8SA 6.6 s 58 521 s ±1 0° Rudder Turns

6PA 16.0 N 140 529 4 Diesels Operatiing

9SA 6.6 s 58 511 Full Backing Bell at CPA

10PA 4.6 N 60 aft/58 fwd 531 Full Twist at CPA

2PB 4.6 N 40 448

TEST METHODS

Healy's noise levels were measured while the ship passed 500 yards to the East of SEAFAC's east acoustic measurement array on a course line parallel to the SEAFAC range centerline. The data comparisons are from the beam aspect. To obtain beam aspect noise signatures, noise levels were averaged over a period starting at 20 degrees (180 yards) prior to

500-yard Closest Point of Approach (CPA) to 20 degrees (180 yards) after CPA, as shown in Figure 2. The location of the ATS was used as the center point for each noise measurement.

The noise measurement hydrophones on the East array were located at depths of 200, 300, 400, and 600 feet. The noise levels for each test were established by averaging the levels

measured at each hydrophone. The noise signatures for each ship and speed were de:rived by averaging the results from all of the tests conducted at that speed. The water depth at SEAF AC near the measurement array was approxima1tely 1200 feet.

Radiated noise measurements acquired during the trial were standardized by using a specified acquisition geometry. No corrections for surface imaging interference have been applied to estimate the free field conditions.

3

Acoustic Trial Results for United States Coast Guard Cutter I-lEAL Y (WAGB-20) (ACTRL 09/14)

Since little is known regarding the directivity of an ice breaker' s radiated noise, and since

off-beam aspect noise levels were not measured, no attempt was made to infer noise levels at

aspects other than those measured on the beam. As a result the comparisons made in this report

wiH not discuss bow or stern aspect noise levels.

DISCUSSION OF THE NOISE SPECTRUM

Often when noise levels are reported, it is common to quote them in terms of a single

number. For example, the noise level from operation of heavy construction equipment may be

reported as 110 dB. Usually this number represents the sum of all the noise energy that occurs

within the frequency range of human hearing (20-20000 Hz). The noise levels in this report for

Healy will be represented also with a single number. This single number was power summed

from I 0 to 31500 Hz. If more information regarding the character of the signature is desired, the

one-third octave spectral format is available upon request.

Ship noise signatures are commonly represented in one-third octave bands. This format shows the distribution of acoustic energy that is emitted by a ship over a wide frequency

sp~:ctrum by plotting noise levels for each standard one-third octave band in a level versus frequency format. This representation graplhically demonstrates the amount of noise energy that

is present at low, mid, and high frequencies, and serves as a tool to identify the predominant

noise sources that make up a ship's total acoustic signature.

The noise spectrum representation is also useful as a noise source ranking tool. For example if a noise spectrum shows that high noise energies are present near 3 kHz, this result

would be important to humans because human hearing is especially sensitivity to noises that

occur at frequencies near 3 kHz. On the other hand, a significant noise level at l 00 Hz might be

less important because human hearing sensitivity at this frequency is relatively low. Use of the

noise spectrum instead of single numbers that represent total energy provides more information regarding the noise source itself and its origin.

HESULTS

BASELINES

Healy 's overall sound levels at 1-yard are presented by speed in Figure 3. The sound

levels ranged from 160 to 182 dB. The underwater noise levels are ship specific noise characteristics driven by the propulsion plant, auxiliary equipment, and propellers. As Healy

increased in speed the underwater radiated noise level also increased. The 4.6 knots sound level

was the lowest and the 16 knot sound level was the highest.

Noise characteristics of a diesel-electric ship at slow speeds typically contain energy from

the diesel generators, the electric propulsion motors, and the frequency converters. Previous

4

Acoustic Trial Results for United States Coast Guard Cutter HEALY (WAGB-20) (ACTRL 09/ 14)

ships have been evaluated with a similar propulsion system where the cycloconverters in combination with the electric propulsion motors controlled the signature below 100 Hz at speeds

less than I I knots (ref. 2)

Other typical ship noise sources are from rotating auxiliary machinery and other

shipboard equipment such as air conditioning plants; water, hydraulic, and oil pumps; motor

generators; and ventilation fans. Due to the time constraints and the scope of the trial, rotating

auxiliary machinery and other shipboard equipment were not identified. The radiated levels

from these other systems are typically lowe:r than the propulsion systems. This means that they are less likely to control the radiated noise levels.

Cavitation, when it occurs, produces substantial acoustic noise. Cavitation occurs when local pressures in the flow field associated with a propeller or hull location drop to very low

vallues. When sufficiently low pressures are reached, water flashes into water vapor and a small

water vapor bubble is created. These bubbles expand and contract violently and produce intense

acoustic pressures that typically results in high noise levels. It is often attributable to the

propeller, but flow at specific locations on a ship's hull can also be a source of cavitation. The

amount of cavitation produced by a ship propeller depends on the design, condition, and the

ship's speed. Healy did not exhibit much cavitation below 11 knots. The 16 knots overall sound

level increased by almost 20 dB above the II knots level. This increase was most likely from

cavitation.

For cavitation occurring at locations on a ship's hull, the speed of the ship, turning

maneuvers, and hull form shapes can be important factors. Incidents of cavitation occurring at rudders, struts, and other hull locations are known to occur. Specific rudder evaluations were

conducted during this testing period to incite cavitation at the rudder.

DIAGNOSTIC TESTS

Rudder Evaluations

Rudder swings of 5 and I 0° were evaluated at 40 and 58 rpm, respectively. lrhese tests

were requested by the ship to investigate a loud noise that was detected on a shipboard acoustic

sensor during a self-noise evaluation conduc~ted a few days prior to this test. It was suspected

that the rudders caused this noise when moved.

The ±5° rudder swing test was conducted at 40 rpm. The rudder was manipulated

several times near CPA. While there was an audible noise with each movement, the OV1::rall sound level was similar to that of th1:: 40 rpm baseline level.

5


The± 10° rudder swing test was conducted at 58 rpm. Each rudder movement was marked at rudder left 10°, rudder amid ship, rudder right 10°, and rudder amid ship. This rudder

movement sequence was repeated from COMEX to FrNEX of the run. Like the 5° rudder swing

test, while there was an audible noise with each movement, the overall sound level was similar to

that of the 58 rpm baseline level.

Full Backing Bell

A full backing bell diagnostic from :8 knots was conducted to determine the maximum

noise level as a result of the evolution. The backing bell reverses the propulsion plant to stop

forward movement. The maximum overall sound level was 195 dB. This was a 35 dB increase

in ithe overall sound level when compared to the 8-knot baseline level.

Full Twist

The full twist test was conducted with the port shaft operating aft at 60 rpm and the

starboard shaft operating forward at 58 rpm. The propulsion plant in this lineup allows Healy to

rotate in a circle with minimal to no forward movement. The overall sound level for this

evolution was 183 dB. This was a 23 dB increase in the overall sound level when compared to

the: 8-knot baseline level.

"Steam" Hammer

Since Healy operates in cold waters steam is used to heat the oily system. Steam pipes run through the oil tanks. The ship reported! hearing a "steam" hammering when steam was aligned to the tanks and were concerned that the noise was radiating into the water. One test was

conducted with the steam secured to the oil tanks. Securing the steam to the oily sys:tems had no

measureable effect on the overall sound lev~~!.

DIESEL-ELECTRIC SHIP COMPARISON

Four ships with similar propulsion plants were selected for comparison. Healy's overall

sound level was compared to other diesel-electric ships that operate in the Arctic region. Healy

was compared at 11 and 16 knots to the other diesel-electric ships. Figure 4 presents the 1 0-knot

level of these ships to the ll -knot Healy ov~~rall sound level. Healy 's radiated noise level was 5 dB lower than the quietest diesel-electric ship. Figure 5 presents Healy 's 16 knots allternate speed

to various speeds (5.6 to 18 knots) of the other diesel-electric ships. Healy 's was 5 dB louder

than Ship B.

Figure 6 compares the overall sound levels by speed and range. Healy's 11 -knot level

was the lowest level by 5 dB. Healy's 16 knot level was the highest level by 5 dB. The last

6


figure, Figure 7, compares Healy 's levels to the maximum and minimum levels of the diesel

ele:ctric ships. The same two speeds and ranges were used for this comparison as Figure 5.

SUMMARY AND CONCLUSIONS

The objective of this test was to compare Healy's overall noise levels at various speeds

wi1th established noise levels of similar diesd-electric ships that are common to the arctic region.

Four diesel-electric ships were used for this comparison.

Healy noise levels were measured at a nominal distance of 500 yards. Thes1~ noise levels

we:re corrected for transmission loss and referenced to a range of 1 yard. Healy was measured at

4.6, 8, 11 and 16 knots. The 4.6 knot level was the lowest with the 16 knot being th<:! h ighest.

When comparing Healy 's overall sound levels to that of other diesel-electric ships Healy

had the lowest level at 11 knots and the highest level at 16 knots.

Other characteristics to note are:

1. Five and 10° rudder movements did not significantly influence the overa ll sound level

of Healy. 2. The full backing bell and the twist were very loud operations.

3. The "steam" hammer was not de:tected during the trial.

7

Acoustic Trial Results for United States Coast Guard Cutter HEALY (WAGB-20) (ACTRL 09114)

18'IGURES

2000 Yml Track Lill e ForliSCGCHEAL Y

Island

Figure 1. Southeast Alaska Acoustic Measurement Facility

8


Beam Aspect -1sovd • e+ 1sovd

---- ----------St;rt f- ~-- / ------

SEAFAC Range Centerline

SOO yd ..

-- --- • Ship'sCourse line Stop

', r::;oo · ..• . : EastArray

e West Array

Figure 2 . Beam Aspect for Noise Measurement

9

190

185

180

:;;175 >o ·-•W .. ..

1:1. 170 0 1:1 ·e ·E 165

IZI :~

'i 160 ·-' .... c =

I~ 155

150

145

140


Healy Overall Sound Levels

4.6knots Sknots 11 knots

Figure 3. Healy Overall Sound Levels by Speed

10

16 knots


Overall Sound Levels, Diesel-Electric Ship Comparision 180 -----------------------------------------------------------

175 r-l --------;:====~---

·~ •:;; 165 +---------------, .. II .. :e '" is ~; 160 +-----ID ~~ ~; :> '" ;~ 155 +----[= "' '0

( I)

150

• uscGCHeaty-11 knots

• Shi'pA -10 knots

Shl'p B -10 knots

• shrpc - to knots

• shrpo -10 knots

Figure 4. Healy Overall Sound Level Compared to Similar Diesel-Electric Ships

11


Overall Sound Levels at, 0 iesei-Eiectric Ship Comparison, Alt Speed

1~ --------------------------------------------------------------

:;; ,..

185 _.__ __________ _

180 -;-----

·: 175 . . ... 0 ~ ·e ''! 170 +-----"" :!!. 'li ~ .... ·~ 165 _,__ __ _

• ,J!

160 ~---

155 +---- -

150 ---- -

• U5CGC Healy - 16 knots

• Ship A- 15 Knots

Shl p B - 18 Knots

• Ship C - 14 Knots

• Ship D- 5.6 Knots

Figure 5. Healy Overall Sound Levtel Compared to Similar Diesel-Electric Ships,

Alternate Speed

12

200

160

'i 140 '5 .. r ~ = 120 ..

·~ II

! too ~

.. ~ 80 ·o ~

~ 60


Diesel-Electric Ships Overall Sound Levels by Speed and Range

USCGC He aly Ship A ShipS ShipC ShlpO

• 500 yards at 10 knot

• 500 yords alt speed

1 yard at 10 knot

• tvard alt speed

Figure 6. Healy vs Relevant Diesel-Electric Ship Overall Sound Levels by

Speed and Range

13

"i' ~ ~ 'i ·~ ~ .. .. , .. 0 b e .. ! "" ~ "' i ... "0 c ~

,J!

zoo

180

160

140

120

100

80


Healy Compared to Diesel-Electric Ship Max and Min Overall Sound Levels

• ShlpM_ •_• ,.._ __ _

• Ship Min 169 F

168

Healy 164 182 110

Figure 7. Healy Compared to Diesel-Electric Ship's Max and Min

Overall Sound Levels at Range and Speed

14

114

128


REFERENCES

(l) Urick, R., Principles of Underwater Sound, McGraw-Hill, New York (1983). (2) CDNSWC, NSWCCD-71 -TR-2002/574, Southeast Alaska Cruise Ship Underwater

Acoustic Noise, October 2002.

15

DISTRIBUTION

Electronic Copy to:

USCGC HEALY CO e-mail address: [email protected]

USCG (David Forcucci) e-mail address: [email protected]

COMNA VSEASYSCOM WASHINGTON DC (SEA 05P1 M. Martin) e-mail address: michael.j .martin@navy .mil

NAVSURFWARCEN SHIPSYSENGSTA PHILADELPHIA PA (A. Boughner) e-mail address: [email protected]

Electronic Blind Copy to:

NA VSURWARCEN CARDEROCK DIY BETHESDA MD Code Name 7110 K. Oneill 7110 F. Anderson 7110 J. Otis 7110 J. Shenk

NA VSURFWARCEN DET PUGET SOUND SILVERDALE W A Code Name 7112 C. Valadez

Blind copy to:

NA VSURFWARCEN DET PUGET SOUND SILVERDALE WA Code Name 7102 Library

oct 2 2 2014 unclassified frc::>m: commanding …icefloe.net/files/wagb20_healy.pdf · document...

Documents