oct 2 2 2014 unclassified frc::>m: commanding …icefloe.net/files/wagb20_healy.pdf · document...
Post on 19-Apr-2018
214 Views
Preview:
TRANSCRIPT
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: john.d.reeves@uscg.mil USCG (David Forcucci) e-mail address: david.forcucci@uscg.mil COMNAVSEASYSCOM WASHINGTON DC (SEA 05P1 M. Martin) e-mail address: michael.j.martin@navy.mil NAVSURFWARCEN SHIPSYSENGSTA PHILADELPHIA PA (A. Boughner) e-mail address: abe.boughner@navy.mil
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
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.
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
Acoustic Trial Results for United States Coast Guard Cutter HEALY (WAGB-20) (ACTRL 09/14)
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
Acoustic Trial Results for United States Coast Guard Cutter HEALY (WAGB-20) (ACTRL 09/14)
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
Acoustic Trial Results for United States Coast Guard Cutter HEALY (WAGB-20) (ACTRL 09/14)
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
Acoustic Trial Results for United States Coast Guard Cutter HEALY (WAGB-20) (ACTRL 09/14)
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
Acoustic Trial Results for United States Coast Guard Cutter HEALY (WAGB-20) (ACTRL 09/14)
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
Acoustic Trial Results for United States Coast Guard Cutter HEALY (WAGB-20) (ACTRL 09/14)
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
Acoustic Trial Results for United States Coast Guard Cutter HEALY (WAGB-20) (ACTRL 09/14)
Healy Overall Sound Levels
4.6knots Sknots 11 knots
Figure 3. Healy Overall Sound Levels by Speed
10
16 knots
Acoustic Trial Results for United States Coast Guard Cutter HEALY (WAGB-20) (ACTRL 09/14)
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
Acoustic Trial Results for United States Coast Guard Cutter HEALY (WAGB-20) (ACTRL 09/14)
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
Acoustic Trial Results for United States Coast Guard Cutter HEALY (WAGB-20) (ACTRL 09/14)
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
Acoustic Trial Results for United States Coast Guard Cutter HEALY (WAGB-20) (ACTRL 09/14)
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
Acoustic Trial Results for United States Coast Guard Cutter HEALY (WAGB-20) (ACTRL 09/14)
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: john.d.reeves@uscg.rnil
USCG (David Forcucci) e-mail address: david.forcucci@uscg.mil
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: abe.boughner@navy.mil
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
top related