Rules for Classification and Construction I Ship...

Rules for Classification and Construction I Ship Technology 1 Seagoing Ships 18 Harmony Class – Rules on Rating Noise and Vibration for Comfort,

Cruise Ships (v > 25 kn)

Edition 2004

The following Rules come into force on June 21th , 2004.

"General Terms and Conditions" of the respective latest edition will be applicable (see Rules for Classification and Construction, I – Ship Technology, Part 0 – Classification and Surveys).

Reproduction by printing or photostatic means is only permissible with the consent of Germanischer Lloyd.

Germanischer Lloyd AG

Head Office Hamburg

Vorsetzen 35, D-20459 Hamburg

Telefon +49 40 3 61 49-0 Telefax +49 40 3 61 49-2 00 [email protected] http://www.gl-group.com

Published by: Germanischer Lloyd AG, Hamburg Printed by: Gebrüder Braasch GmbH, Hamburg

http://www.gl-group.com/

Table of Contents

Section 1 Classification

A. Scope .......................................................................................................................................... 1- 1 B. Harmony Criteria Numbers (hc) ................................................................................................. 1- 1 C. Class Notation ............................................................................................................................. 1- 1

Section 2 Required Noise and Vibration Limits

A. General ........................................................................................................................................ 2- 1 C. Vibration Requirements .............................................................................................................. 2- 1

Section 3 Required Measurements

A. General ........................................................................................................................................ 3- 1 B. Measuring Conditions ................................................................................................................. 3- 1 C. Performance of Measurements .................................................................................................... 3- 2 D. Survey Programmes .................................................................................................................... 3- 7 E. Survey Report ............................................................................................................................. 3- 7

Section 4 Calculation Procedure of hcClass_Notation

A. Determination of single hc .......................................................................................................... 4- 1 B. Averaging of single hc ................................................................................................................ 4- 1 C. Determination of hcClass_Notation ................................................................................................ 4- 2

Annex A Standards

A. General ........................................................................................................................................ A- 1 B. Standards .................................................................................................................................... A- 1

Annex B Definitions

A. Important Definitions .................................................................................................................. B- 1

Annex C Recommendations to Reduce Noise and Vibration

A. General ........................................................................................................................................ C- 1 B. Considerations Regarding Excitation Forces .............................................................................. C- 1 C. Theoretical Investigations ........................................................................................................... C- 1 D. Secondary Measures ................................................................................................................... C- 2 E. Supplementary Measurements during Production Phase ............................................................ C- 2

Annex D Protocol Sheet

A. Measurement Protocol Sheet ...................................................................................................... D- 1

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Table of Contents Chapter 18Page 3

Section 1

Classification

A. Scope

1. In general, these Rules are based on national and international standards listed in Annex A. They will be adapted to the latest editions of these standards when deemed necessary or will be modified to ac-count for the progress of knowledge. The Rules reflect the state of the art in vibration and acoustic technol-ogy.

2. Some important definitions for expressions used in these Rules are given in Annex B.

3. Among various comfort-promoting factors (e.g. decor and furniture of cabins and public spaces, indoor climate, board service, ship motions etc.), two main parameters determining the comfort on board a passenger ship are dealt with in these Rules: noise and vibration.

4. In this context, noise and vibration are de-fined as follows:

– Noise:

Audible air pressure variations, generated for instance by main engines, propellers, auxiliary machinery, systems and persons within the fre-quency range of 16 to 16 000 Hz.

– Vibration:

Structural oscillations in the frequency range of 1 to 80 Hz

5. The influence of ship motions (seasickness) on human well-being is not considered in these Rules.

6. These Rules are intended to support owners and shipyards to specify requirements regarding com-fort for passengers and crew on board seagoing cruise ships.

7. Requirements according to current regula-tions of the responsible flag state regarding maximum noise and vibration levels in crew spaces have to be fulfilled independently of these Rules.

8. If the maximum speed of the passenger ship is equal or less than 25 knots, the requirements de-fined for cruise vessels < 25 knots must be applied.

9. If the maximum speed of the passenger ship exceeds v = 7,16 ⋅ Δ1/6 [knots], the requirements defined for high speed craft have to be applied.

10. If the length between perpendiculars is less than 80 m, limit values given in these Rules do not apply. They shall be agreed upon separately after conferring with Germanischer Lloyd (GL).

B. Harmony Criteria Numbers (hc)

To allow for a graduation of noise and vibration lev-els, 5 harmony criteria numbers (hc) are introduced:

hc = E =̂ ∗∗∗∗∗ excellent comfort

hc = 1 =̂ ∗∗∗∗ very high comfort

hc = 2 =̂ ∗∗∗ high comfort

hc = 3 =̂ ∗∗ moderate comfort

hc = 4 =̂ ∗ acceptable comfort

Two separate numbers, hcpass and hccrew, reflect the level attained for passenger and crew spaces, respec-tively.

1. Respective limit values of noise and vibration are defined in Section 2.

2. Compliance with criteria given in these Rules shall be verified through measurements performed under defined conditions at specified locations; see Section 3.

C. Class Notation

1. Upon request, ships complying with these Rules are granted the following special Notation of Harmony Class

( )pass crewHC hc /hc

For instance, HC (2/3) corresponds to a high comfort for passengers and a moderate comfort for crew, ac-cording to B.

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Section 1 Classification Chapter 18Page 1–1

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2. For a series of ships, the required noise meas-urements have to be conducted individually for each ship of the series. Regarding vibration measurements, a reduced measurement programme can be accepted for sister ships.

3. After modifications (e.g. conversions) that might influence the noise and vibration behaviour, the class notation has to be reconfirmed by Germanischer Lloyd.

Chapter 18 Page 1–2

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Section 2

Required Noise and Vibration Limits

A. General

1. Requirements given in these Rules refer to human well-being only. However, to achieve a cer-tain level of noise and vibration comfort, it must be ensured that main and auxiliary machinery do not vibrate heavily. Therefore, limit values given in cor-responding standards or Classification Rules, for instance Part 1 – Seagoing Ships, Chapter 2 – Machinery Installations, Section 2, Fig. 2.1, shall be observed, too.

2. Requirements regarding acoustic privacy are given in addition to those for noise and vibration.

3. Requirements for noise and vibration are presented for three operating conditions: – sea mode – harbour operation – thruster operation

The noise and vibration limits given for sea mode operation form an upper bound for any operation mode at typical ship speeds.

4. Requirements regarding measurements for the three operating conditions are given in Section 3, B.

5. Limits are given separately for passenger and crew spaces.

6. Requirements are related to different imis-sion zones as defined by frame A, B, C and D. The principal arrangement of these zones is shown in Fig.

2.1 for a typical fast passenger vessel, see also "Imis-sion zones" in Annex B.

B. Noise Requirements

1. Most relevant standards are ISO 2923, ISO 717/1 and ISO 717/2.

2. Required noise limit values depending on the harmony criteria number (hc) are listed in Tables 2.1 to 2.4.

3. The measurement procedure and the calcula-tion of the hc achieved by noise measurements are described in Section 3, C. and Section 4, respectively.

C. Vibration Requirements

1. The most relevant vibration standard is ISO 6954, edition 2000-12-15. The limit values refer, consequently, to the overall frequency-weighted rms value in the range of 1 to 80 Hz. The vibration veloci-ties are given in mm/s.

2. Required vibration limit values depending on the harmony criteria number (hc) are listed in Tables 2.5 and 2.6.

3. The measurement procedure and the calcula-tion of the hc achieved by vibration measurements are described in Section 3, C. and Section 4, respec-tively.

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Fig. 2.1 Imission zones

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Section 2 Required Noise and Vibration Limits Chapter 18Page 2–1

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Table 2.1 Noise limits, passenger spaces

Sea Mode 1, 2 Harbour Operation 1, 2 Thruster

Operation 2 , 3, 4

hc hc hc

Noise level limits [dB(A)]

E 1 2 3 4 E 1 2 3 4 E 1 2 3 4

Indoor spaces aft of frame A

First-class cabins 50 52 54 56 58 44 46 48 50 52 52 54 56 58 60

Standard cabins 54 56 58 60 60 46 48 50 52 54 56 58 60 62 64

Public spaces, type 1 and 2 56 58 60 62 64 52 54 56 58 60 60 62 64 66 68

Corridors, staircases 58 60 62 64 64 54 56 58 60 62 –– –– –– –– ––

Indoor spaces between frame A and C


Standard cabins 50 52 54 56 58 46 48 50 52 54 54 56 58 60 62



Indoor spaces between frame C and D


Standard cabins 48 50 52 54 56 46 48 50 52 54 54 56 58 60 62



Indoor spaces forward of frame D


Standard cabins 46 48 50 52 54 46 48 50 52 54 56 58 60 62 64



Outdoor spaces

Open deck recreation areas 64 66 68 70 75 64 66 68 70 72 64 66 68 70 72

Exhaust/supply air openings in open deck recreation areas 5 68 70 72 75 80 68 70 72 75 80 68 70 72 75 80

1 In each space the noise level generated only by air-conditioning and mechanical ventilation systems must be at least 4 dB(A) below the required noise limit value for harbour operation.

2 In each sanitary cell the noise level generated only by air-conditioning exhaust air systems at full capacity must not be more than 5 dB(A) above the required noise limit value for harbour operation.

3 To be verified by measurements in the vicinity of thrusters only. Passenger indoor spaces aft of Frame A shall be considered during stern thruster operation only. All thrusters running at not less than 70 % of full load. The noise limits shall be maintained also in standby operation of thrusters.

4 Limit values valid, provided that thrusters are in operation for a maximum of 4 hours out of 24 hours. 5 At a distance of 1,5 m.


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Table 2.2 Noise limits for acoustic privacy, passenger spaces

On board acoustic privacy – sound insulation (minimum required weighted apparent sound insulation index [dB]

according to ISO 717/1 and ISO 140/4)

hc Arrangements: E 1 2 3 4

First-class cabins to first-class cabins (incl. bath to bath) 42 40 38 36 34 First-class cabins to standard cabins (incl. bath to bath) 42 40 38 36 34

Standard cabins to standard cabins (incl. bath to bath) 40 38 36 34 32

First-class cabins to corridors 40 38 36 34 32

Standard cabins to corridors 38 36 34 32 30

Pax cabins to crew spaces 50 48 46 44 42

Pax cabins to public spaces type 1 64 62 60 58 56

Pax cabins to public spaces type 2 58 56 54 52 50

Pax cabins to staircases 1 58 56 54 52 50

Pax cabins to engine room casings, elevator casings etc. 2 60 58 56 54 52

Pax cabins to HVAC rooms 3 58 56 54 52 50

Pax cabins to engine rooms 4 64 62 60 58 56

On board acoustic privacy – impact sound insulation (maximum permissible normalized sound pressure level index [dB]


hc Arrangements: E 1 2 3 4

Pax cabins adjacent to pax cabins (soft floor) 46 48 50 52 54

Pax cabins adjacent to corridors (soft floor) 46 48 50 52 54

Pax cabins adjacent to crew spaces 46 48 50 52 54

Pax cabins adjacent to public spaces type 1 (soft, hard floors) 46 48 50 52 54

Pax cabins adjacent to public spaces of type 2 (hard floor) 48 50 52 54 56

Pax cabins adjacent to public spaces of type 2 (soft floor) 46 48 50 52 54

Pax cabins adjacent to open deck recreation areas (hard floor) 50 52 54 56 58

Pax cabins adjacent to jogging paths, dance floors etc. 5 5 5 54 56

Pax cabins adjacent to service spaces (galleys, pantries etc.) 46 48 50 52 54

1 In general, the number of passenger cabins located adjacent to staircases have to be minimized. 2 Number of passenger cabins located adjacent to engine rooms and elevator casings etc. should be minimized. If possible, acoustic

buffer zones (e.g., service stores, lockers etc.) should be arranged between cabins and casings. The average sound pressure level in engine room casings must be limited to max. 100 dB(A).

3 Average sound pressure level in HVAC rooms located adjacent to passenger cabins must be limited to max. 80 dB(A). 4 Arrangement of passenger cabins adjacent to engine rooms should be avoided. Otherwise specific provisions are required to achieve

limit values.

5 Arrangement of passenger and crew cabins below sport courts etc. should be avoided. However, if so arranged the on board impact sound insulation index for sport courts etc. must be agreed upon between owner, yard and Germanischer Lloyd.

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Table 2.3 Noise limits, crew spaces

Sea Mode 1 Harbour Operation 1 Thruster

Operation 2, 3

hc hc hc

Noise level limits [dB(A)]

E 1 2 3 4 E 1 2 3 4 E 1 2 3 4

Work spaces

Machinery spaces (not continuously manned) 5 110 110 110 110 110 110 110 110 110 110 110 110 110 110 110

Engine control rooms 69 71 73 75 75 64 66 68 70 72 67 69 71 73 75Workshops 80 85 85 85 85 80 80 80 80 80 –– –– –– –– ––Open deck working areas 4 75 75 80 85 85 75 75 80 80 85 75 75 80 80 85Stores 5 80 85 90 90 90 75 75 80 85 85 –– –– –– –– ––Indoor spaces not specified 5 90 90 90 90 90 90 90 90 90 90 –– –– –– –– ––

Service spaces

Galleys 6 68 70 72 75 75 66 68 70 75 75 68 70 72 75 75Serveries, pantries 6 66 68 70 75 75 66 68 70 75 75 66 68 70 75 75

Navigation spaces

Navigation bridge and chart rooms 55 55 60 60 65 55 55 60 60 65 58 58 60 60 65Radio rooms 55 55 60 60 60 55 55 60 60 60 55 55 60 60 60Listing posts, including outdoor bridge wings 7 65 65 70 70 70 65 65 65 70 70 65 65 70 70 70

Accommodation spaces

Day and sleeping rooms / officers 50 52 54 56 58 50 52 54 56 58 62 64 66 68 70Day and sleeping rooms / others 54 56 58 60 60 52 54 56 58 60 64 66 68 70 72Mess rooms, offices, recreation rooms 59 61 63 65 65 57 59 61 63 65 66 68 70 72 74Hospitals 54 56 58 60 60 54 56 58 60 60 64 66 68 70 72Gymnasiums, treatment rooms 57 59 61 63 65 57 59 61 63 65 –– –– –– –– ––Corridors adjacent to cabins 58 60 62 64 66 56 58 60 62 64 –– –– –– –– ––Open deck recreation areas 68 70 72 75 75 68 70 72 75 75 –– –– –– –– ––1 In each space the noise level generated only by air-conditioning and mechanical ventilation systems must be limited to at least 4 dB(A)

below the required noise limit value for harbour operation (excluding work spaces and open recreation areas).

2 To be verified by measurements in the vicinity of thrusters only. All thrusters running at not less than 70 % of full load. The noise limits are also to be maintained in standby operation of the thrusters.

3 Limit values valid provided that thrusters are in operation for a maximum of 4 hours out of 24 hours.

4 Spaces requiring verbal communication when berthing the ship (maximum 4 hours out of 24 hours).

5 Reference is made to IMO Resolution A.468 (XII) – ear protectors should be worn when the noise level is above 85 dB(A).

6 With mechanical ventilation in normal operation.

7 Reference is made to IMO Resolution A.468 (XII) – which also requires that the noise level at ¾ speed does not exceed 68 dB in the 1/1 octave band at 250 Hz and does not exceed 63 dB in the 1/1 octave band at 500 Hz.



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Table 2.4 Noise limits for acoustic privacy, crew spaces

On board acoustic privacy – sound insulation (minimum required weighted apparent sound insulation index [dB]


hc Arrangements:

E 1 2 3 4

Cabins to cabins 40 38 36 34 32 Cabins to corridors 38 36 34 32 30 Cabins to stairways 56 54 52 50 48 Cabins to engine room casings, elevator casings etc. 1 58 56 54 52 50 Cabins to mess rooms, hospitals, gymnasiums, service spaces etc. 58 56 54 52 50 Cabins to engine rooms 2 60 58 56 54 52 1 The number of cabins located adjacent to engine rooms and elevator casings etc. should be minimized. If possible, acoustic buffer

zones (e.g., corridors, service stores, lockers etc.) should be arranged between cabins and casings. The average sound pressure level in engine room casings shall be limited to max. 100 dB(A).

2 The arrangement of cabins adjacent to engine rooms should be avoided. Otherwise specific provisions are required to achieve limit values.

On board acoustic privacy – impact sound insulation (maximum permissible normalized sound pressure level [dB]


hc Arrangements:

E 1 2 3 4

Cabins adjacent to cabins 52 54 56 58 60

Cabins adjacent to dance floors, stages etc. 50 52 54 56 58

Cabins adjacent to gymnasiums 52 54 56 58 60

Cabins adjacent to service spaces (e.g. galleys, pantries etc.) 52 54 56 58 60

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Table 2.5 Vibration limits, passenger spaces

Sea Mode Harbour

Operation Thruster

Operation 1

hc hc hc

Vibration limits [mm/s]

(overall frequency weighted rms value 1 to 80 Hz)

E 1 2 3 4 E 1 2 3 4 E 1 2 3 4

Indoor spaces aft of frame B

First-class cabins 1.4 1.8 2.2 2.6 3.0 –– –– –– –– –– 1.6 2.0 2.4 2.8 3.2

Standard cabins 2.0 2.4 2.8 3.2 3.2 –– –– –– –– –– 2.0 2.4 2.8 3.2 3.6

Public spaces, short exposure time 2.8 3.2 3.6 4.0 4.4 –– –– –– –– –– –– –– –– –– ––

Public spaces, long exposure time 2.0 2.4 2.8 3.2 3.6 –– –– –– –– –– –– –– –– –– ––

Corridors, staircases –– –– –– –– –– –– –– –– –– –– –– –– –– –– ––

Indoor spaces forward of frame B

First-class cabins 1.2 1.6 2.0 2.4 2.8 –– –– –– –– –– 1.6 2.0 2.4 2.8 3.2

Standard cabins 1.6 2.0 2.4 2.8 3.2 –– –– –– –– –– 2.0 2.4 2.8 3.2 3.6

Public spaces, short exposure time 2.4 2.8 3.2 3.6 4.0 –– –– –– –– –– –– –– –– –– ––

Public spaces, long exposure time 1.8 2.2 2.6 3.0 3.4 –– –– –– –– –– –– –– –– –– ––

Corridors, staircases –– –– –– –– –– –– –– –– –– –– –– –– –– –– ––

Outdoor spaces aft of frame B

Open deck recreation areas 2.6 3.0 3.4 3.8 4.2 –– –– –– –– –– –– –– –– –– ––

Open deck recreation areas of overhangs 3.0 3.5 4.0 4.5 5.0 –– –– –– –– –– –– –– –– –– ––

Outdoor spaces forward of frame B

Open deck recreation areas 2.4 2.8 3.2 3.6 4.0 –– –– –– –– –– –– –– –– –– ––

Open deck recreation areas of overhangs 2.6 3.0 3.4 3.8 4.2 –– –– –– –– –– –– –– –– –– ––1 Thrusters operating at not less than 70 % of full load.



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Table 2.6 Vibration limits, crew spaces

Sea Mode Harbour

Operation Thruster

Operation 1

hc hc hc

Vibration level limits [mm/s]

(overall frequency weighted rms value 1 to 80 Hz)

E 1 2 3 4 E 1 2 3 4 E 1 2 3 4

Work spaces

Machinery spaces (not continuously manned) 4.8 5.2 5.6 6.0 6.0 –– –– –– –– –– –– –– –– –– ––Engine control rooms 2.8 3.2 3.6 4.0 4.0 –– –– –– –– –– –– –– –– –– ––Workshops 3.6 4.0 4.4 4.8 4.8 –– –– –– –– –– –– –– –– –– ––Stores 4.8 5.2 5.6 6.0 6.0 –– –– –– –– –– –– –– –– –– ––Indoor spaces not specified 4.8 5.2 5.6 6.0 6.0 –– –– –– –– –– –– –– –– –– ––

Service spaces

Galleys 2.5 3.0 3.5 4.0 4.0 –– –– –– –– –– –– –– –– –– ––Serveries and pantries 2.8 3.2 3.6 4.0 4.0 –– –– –– –– –– –– –– –– –– ––

Navigation spaces

Navigation bridges and chart rooms 2.5 3.0 3.5 4.0 4.0 –– –– –– –– –– –– –– –– –– ––Radio rooms 2.5 3.0 3.5 4.0 4.0 –– –– –– –– –– –– –– –– –– ––Listing posts including navigation bridge wings 3.2 3.6 4.0 4.4 4.8 –– –– –– –– –– –– –– –– –– ––

Accommodation spaces

Day and sleeping rooms / officers 1.7 2.2 2.7 3.2 3.2 –– –– –– –– –– 2.0 2.5 3.0 3.5 4.0Day and sleeping rooms / others 2.0 2.4 2.8 3.2 3.6 –– –– –– –– –– –– –– –– –– ––Mess rooms, offices, recreation rooms 2.4 2.8 3.2 3.6 3.6 –– –– –– –– –– –– –– –– –– ––Hospitals 1.7 2.2 2.7 3.2 3.2 –– –– –– –– –– –– –– –– –– ––Gymnasiums, treatment rooms 2.4 2.8 3.2 3.6 3.6 –– –– –– –– –– –– –– –– –– ––Corridors adjacent to cabins –– –– –– –– –– –– –– –– –– –– –– –– –– –– ––Open deck recreation areas 3.0 3.4 3.8 4.2 4.6 –– –– –– –– –– –– –– –– –– ––1 Thrusters operating at not less than 70 % of full load

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Section 3

Required Measurements

A. General

1. Noise and vibration measurements and their evaluation shall be carried out by experienced techni-cians employed by a company authorized by GL. If desired, GL will conduct measurements with own experts.

2. Propulsion machinery power shall be verified during measurements.

3. Measurements shall be witnessed by a GL Surveyor.

B. Measuring Conditions

1. Sea Mode

1.1 Propulsion machinery shall produce the nec-essary power to reach the service speed of the vessel as contractually agreed on. Power shall not be less than 85 % of MCR.

1.2 Controllable pitch propellers, if any, to be in normal seagoing position.

1.3 A condition with operating stabilizers to be considered.

1.4 To exclude shallow water effects the mini-mum water depth required for measurements has to be calculated for each ship individually based on the Depth Froude Number. The loading condition should be the same as specified in the contract. Deviations shall be submitted to GL for approval prior to trials. For ships normally operating in shallow waters, corre-sponding conditions have to be chosen for measure-ments.

1.5 Sea state 3 (significant wave height approx. 1,25 m) and a wind speed of 4 Bft should not be ex-ceeded. For more severe weather conditions, the ac-ceptance of measurements will be decided by GL on a case-by-case basis.

1.6 The course of the vessel shall be as straight as possible. Minimum rudder movement is imperative. Rudder angles shall not exceed ± 2 degrees. 1.7 The ship shall be fully outfitted, and all sys-tems contributing to noise and vibration shall be in

normal seagoing condition, e.g. all auxiliary machin-ery, navigation instruments, radar sets, etc. shall be in normal operation throughout measurements. The communication radio shall be turned on, but not oper-ating.

Mechanical ventilation and air-conditioning equip-ment shall be in normal operation (capacity to be in accordance with design conditions). All air-conditioning systems shall be adjusted prior to meas-urements.

1.8 Noise and vibration caused by any unneces-sary human activity shall be avoided.

1.9 Passenger entertainment and public address systems shall be switched off.

1.10 No passengers shall be on board. Exceptions may be permitted.

1.11 Doors and windows shall, in general, be closed.

2. Harbour Operation

2.1 Measurements are permissible for water depths smaller than for Sea Mode. The water depth present during harbour measurements shall be re-ported.

2.2 The presence of large noise-reflecting areas in the vicinity of the vessel shall be reported.

2.3 The influence of external noise sources, such as traffic, workshops, etc., shall be reduced to a mini-mum.

2.4 All machinery, mechanical ventilation and air-conditioning equipment to be running in normal port condition, as contractually agreed on between owner and shipyard.

2.5 Requirements according to 1.7 to 1.11 apply as well.

3. Thruster Operation

3.1 Measurements shall be conducted in an open sea area. The water depth shall be reported.

3.2 Ship speed shall be close to zero.

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3.3 All machinery shall be running in normal condition as necessary for Thruster Operation with not less than 70 % of full load for each thruster.

3.4 Additional noise measurements shall be taken in selected pax and crew cabins during standby opera-tion of thrusters.

3.5 Requirements according to 1.5 and 1.7 to 1.11 apply as well.

C. Performance of Measurements

1. Noise

1.1 Instrumentation

1.1.1 Integrating-averaging sound level meters shall be applied. These should be able to store the measured data.

1.1.2 The instrumentation system including micro-phone, cable and recording devices shall meet re-quirements for a type 1 instrument as specified in IEC 804.

1.1.3 The microphone shall be calibrated to have an essentially flat frequency response in a diffuse sound field.

1.1.4 A windscreen shall be used for outdoor meas-urements.

1.1.5 If a windscreen is used for indoor measure-ments, the measured A-weighted sound pressure level shall not be influenced by more than 0,5 dB (A).

1.1.6 1/1 or 1/3 octave band filters shall comply with the requirements of IEC 1260.

1.1.7 Class 1 sound calibrators complying with the requirements of IEC 942 shall be used.

1.1.8 Calibration of measuring instrumentation:

– The compliance of the integrating-averaging sound level meter with requirements of IEC 804 shall be verified by the manufacturer or other authorized organization at least every two years.

– The compliance of the sound calibrator with requirements of IEC 942 shall be verified by the manufacturer or other authorized organization at least every two years.

– The date of last verification and confirmation of compliance with relevant IEC standards shall be recorded. Calibration sheets shall be provided.

1.1.9 An instrument suitable of storing time signals in case of subjectively annoying low-frequency sound (booming) or obvious tonal components shall be pro-vided.

1.2 Number of measurement positions

1.2.1 Noise level measurements in passenger spaces

1.2.1.1 Cabins

The total number of measurement positions to be taken in pax cabins depends on the net living space of each room belonging to the individual pax cabin.

– net living space less than or equal to 20 m2:

one measurement position in the middle of the room

– net living space greater than 20 m2:

at least two measurement positions in the room.

On ships for which the total number of passengers is less than or equal to 150, noise measurements shall be conducted in each pax cabin.

On ships for which the total number of passengers is greater than 150, the number of required measurement locations are defined in Table 3.1, expressed in verifi-cation percentages.

1.2.1.2 Public spaces of type 1 and 2

Measurement positions shall be chosen in a way that the noise situation can be evaluated in each individual public space.

In small public spaces with an area less than or equal to 40 m², at least one measurement position shall be taken in the centre of the room.

1.2.1.3 Corridors

Measurement positions shall be chosen where maxi-mum noise levels can be expected (especially close to air inlets and outlets of air-conditioning systems, cas-ings, etc.). Furthermore, the maximum distance be-tween each two measurement positions depends on the operating condition and the emission zone as follows:

– Sea Mode; aft of Frame C: 12 m

– Sea Mode; forward of Frame C: 18 m

– Harbour Operation; aft of Frame C: 18 m

– Harbour Operation; forward of Frame C: 25 m

Thruster Operation; measurements not required


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Table 3.1 Required scope of noise measurements, passenger and crew spaces (Number of Passengers > 150)

Sea Mode Harbour Operation 2 Thruster

Operation 3 Verification percentages 1

All hc All hc All hc

Indoor spaces aft of frame A

Passenger first-class cabins 4 ≥ 50 ≥ 10 ≥ 20

Passenger standard cabins 4 ≥ 25 ≥ 10 ≥ 20

Crew day and sleeping rooms 4 ≥ 30 ≥ 10 ≥ 20

Crew mess and recreation rooms 4 100 ≥ 25 ≥ 50

Work spaces, control rooms, offices, etc. 4 100 ≥ 25 ––

Indoor spaces between frame A and C

Passenger first-class cabins ≥ 25 ≥ 10 ≥ 10

Passenger standard cabins ≥ 25 ≥ 10 ≥ 10

Crew day and sleeping rooms ≥ 30 ≥ 10 ≥ 10

Crew mess and recreation rooms 100 ≥ 25 ≥ 25

Work spaces, control rooms, offices etc. 100 ≥ 25 ––

Indoor spaces between frame C and D




Crew mess and recreation rooms ≥ 25 ≥ 25 ≥ 25

Work spaces, control rooms, offices etc. ≥ 25 ≥ 25 ––

Indoor spaces forward of frame D




Mess and recreation rooms ≥ 25 ≥ 25 ≥ 50

Work spaces, control rooms, offices etc. ≥ 25 ≥ 25 –– 1 For spaces not referred to in this table, C.1.2.1 and 1.2.2 applies. 2 Especially spaces in the vicinity of main noise sources (where maximum noise levels can be expected or where obviously high noise

levels are observed during the noise survey). 3 Especially spaces close to thrusters (where maximum noise levels can be expected or where obviously high noise levels are observed

during the noise survey). 4 Passenger indoor spaces aft of frame A shall be considered during stern thruster operation only.

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1.2.1.4 Main staircases

Measurement positions shall be taken at each staircase platform of each main staircase in Sea Mode and Har-bour Operation.

1.2.1.5 Outdoor spaces

Total numbers of measurement positions mainly de-pend on the size of the passenger ship and on number of air-conditioning and mechanical ventilation air supply/exhaust openings located close to passenger recreation areas.

In general, several measurement positions shall be taken on passengers’ open recreation deck spaces directly exposed to exhaust gas noise of the main propulsion plant and auxiliary machinery. The same applies to recreation areas located close to air sup-ply/exhaust openings of mechanical ventilation sys-tems.

The final noise measurement positions on passengers’ open recreation deck spaces will be determined by GL.

1.2.2 Noise level measurements in crew spaces

1.2.2.1 Accommodation and work spaces

The measurement positions shall be chosen according to IMO Resolution A.486 (XII), Chapter 2.8.

On ships for which the total number of passengers is less than or equal to 150, noise measurements shall be conducted in each crew cabin for Sea Mode condition.

On ships for which the total number of passengers is greater than 150, the number of noise measurements required for Sea Mode condition is given in Table 3.1, expressed in verification percentages.

Number of measurement positions for Harbour Opera-tion and Thruster Operation are given in Table 3.1, expressed in verification percentages, irrespective of the number of passengers.

1.2.3 Acoustic privacy measurements

1.2.3.1 Sound insulation

Measurements shall be conducted according to ISO 717/1 and ISO 140/4 in crew and passenger spaces.

Measurements shall be conducted in at least two cab-ins of each type.

1.2.3.2 Impact sound insulation

Measurements shall be conducted according to ISO 717/2 and ISO 140/7 in crew and passenger spaces.

Measurements shall be conducted at least in two cab-ins located close to relevant spaces for each combina-tion of cabin type and floor construction.

1.3 Measurement procedure

1.3.1 General

1.3.1.1 The most relevant standards to be observed are:

– ISO 2923

– ISO 140

– ISO 717

– E DIN 45681

1.3.1.2 A maximum of three persons are allowed to stay in the same indoor space/cabin when the noise measurements are being conducted.

1.3.1.3 The equivalent continuous A-weighted sound pressure level in dB(A) shall be measured. The corre-sponding band levels of the 1/1 octave band mid fre-quencies of at least 31,5 Hz to 8 000 Hz shall be measured simultaneously. After each measurement, all measured data shall be stored on the hard disk of the sound level meter.

1.3.1.4 The calibration of the measuring instruments shall be checked immediately before and after each period of use. The calibration level shall be measured and stored after each calibration.

1.3.1.5 Overall sound pressure level in dB(A), file number of the data storage (ID number), measurement location, noise limit according to hc target and subjec-tive noise impression shall be recorded and immedi-ately noted in measurement protocol sheets after re-cording, see Annex D.

1.3.1.6 The sound level instrumentation shall be set to "fast" response. The measuring time shall be at least 15 seconds if the fluctuation of the overall sound pres-sure level is equal to or less than ± 3 dB(A). If fluctua-tions exceed ± 3 dB(A) or if the sound is cyclic or irregular, the instrument setting shall be changed to "slow" response and the measuring time shall be ex-tended to at least 30 seconds.

1.3.1.7 During each measurement, the microphone shall slowly be moved horizontally and/or vertically over a distance of approximately ± 0,5 m.

1.3.1.8 In spaces such as radio and radar rooms, care should be taken to ensure that any electrical interfer-ence present does not give rise to a false indication of the noise level.

1.3.1.9 A microphone windscreen shall be used when measuring noise levels on open deck spaces and also below decks where there is any substantial air move-ment. When used for indoor spaces, 1.1.5 has to be observed.

1.3.1.10 Wind noise, e.g. wind trash, singing or simi-lar effects has to be reported for surveyed outdoor spaces.



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1.3.1.11 For measurements in passenger spaces, it is recommended to position the microphone at an aver-age height of approx. 1,4 m to cover both the position of a sitting and a standing person.

1.3.1.12 The microphone position should not be closer than 0,5 m to boundary surfaces, e.g. lining walls, ceilings, windows, floors and bulkheads.

1.3.2 Acoustic privacy

1.3.2.1 Measurements shall be conducted according to ISO 717-1, ISO 717-2, ISO 140/4 and ISO 140/7.

1.3.2.2 For sound transmission measurements be-tween corridor and cabin, the microphone position in the cabin (receiver room) shall be located where pas-sengers normally stay.

1.3.3 Presence of secondary noise sources

In general, secondary noise sources (e.g. rattling, knocking and squeaking noises from doors, panels, furniture, fittings or fixtures, etc.) shall be eliminated in crew and passenger accommodation spaces.

1.3.4 Presence of obvious tonal components

1.3.4.1 In general, obvious tonal components in passenger and crew spaces will not be accepted for any of the conditions: Sea Mode, Harbour Operation and Thruster Operation.

1.3.4.2 Obvious tonal components audible in pax cabins and/or in passenger public spaces and/or in crew accommodation spaces shall be reported, see Annex D.

1.3.4.3 The tone rating procedure, as mentioned in Annex B, shall be applied in passenger spaces where steady noise with audible discrete tones is present. In general, the application of this tone rating procedure does not depend on the hc target, but will be handled in a stricter manner for ships with a hc target E, 1 or 2.

1.3.4.4 This procedure shall also be applied in crew accommodation spaces on board ships with an hc target of E, 1 or 2. For ships with an hc target 3 or 4, IMO Resolution A.468 (XII) shall be applied.

1.3.5 Presence of booming effects

1.3.5.1 In general, the presence of annoying low-frequency sound (booming effects) occurring in pas-senger and crew spaces during Sea Mode, Harbour Operation and Thruster Operation will not be ac-cepted.

1.3.5.2 Annoying low-frequency sound audible in pax cabins and/or in passenger public spaces and/or in crew accommodation spaces shall be reported, see Annex D.

1.3.5.3 When booming effects are present in passen-ger spaces, the booming rating procedure as men-

tioned in Annex B shall be applied, irrespective of the hc target chosen for the ship.

1.3.5.3.1 The procedure as described in IMO Resolu-tion A.468 (XII) shall be applied in crew accommoda-tion spaces and does not depend on the hc target cho-sen for the ship.

1.3.6 Presence of impulse noise

1.3.6.1 In general, impulse noise in passenger and crew spaces will not be accepted for any of the condi-tions: Sea Mode, Harbour Operation and Thruster Operation.

1.3.6.2 The presence of impulse noise shall be de-termined according to the definition as given in Annex B.

2. Vibration

2.1 Instrumentation

2.1.1 The equipment shall be calibrated at periodic intervals of not more than two years. Calibration sheets shall be provided.

2.1.2 On non-magnetic floors, measuring sensors should preferably be mounted on a three-legged plate with a minimum weight of 1500 g.

2.1.3 The instrumentation shall allow for calcula-tion of the weighted rms value in terms of vibration velocity according to ISO 6954.

2.1.4 Provision shall be made for the storage of all spectra and a limited number of time records.

2.1.5 The instrumentation shall comply with re-quirements of ISO 8041.

2.2 Number of measurement positions

2.2.1 The required number of measurement posi-tions depends on the vibration direction to be meas-ured (longitudinal, transverse or vertical).

2.2.2 Measurement positions for assessing longitu-dinal vibrations shall be chosen in a way that meas-urement results adequately reflect the global level. At least one measurement position should be chosen at the inner bottom, the strength (weather) deck and the top deck level.

2.2.3 Measurement positions for assessing trans-verse vibrations shall be chosen in a way that results adequately reflect the global level. Measurement posi-tions should be located at the strength (weather) deck of the vessel and at the highest deck of ship. The lon-gitudinal distance of measurement positions shall not exceed Lpp/4.

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2.2.4 The scope of measurements in vertical direc-tion for passenger and crew accommodation areas, expressed in verification percentages, is listed in Table 3.2.

2.2.5 In rooms/spaces of a more unique character, e.g. public spaces, open deck recreation areas, offices, mess rooms, etc., the vertical vibration level shall be measured individually for each room/space. Normally, measurements will be carried out in the centre of the room.

2.2.6 For rooms/spaces with an area exceeding 40 m2, several measurement positions shall be chosen (at least one position per 40 m2) in a way that subjec-tively high vibrations in vertical direction are covered.

2.3 Measurement procedure

2.3.1 The relevant standards are ISO 4867 and 4868.

2.3.2 The velocity spectrum, achieved by an FFT analysis of the measured time series, shall generally be

made available, i.e. during sea trials. The spectrum shall be stored.

2.3.3 If desired by GL experts, for instance if beat-ing occurs, time records of selected measurement positions shall be recorded and stored.

2.3.4 To ensure comparability of the spectra, the following parameters shall be applied for data acquisi-tion and signal processing:

– measurement time per point: ≥ 1 min.

– sampling rate: ≥ 300 1/s.

– spectral frequency range: 1 Hz to 80 Hz

– minimum spectral resolution: 0,2 Hz

– FFT window function: flat top (if not available: Hanning window)

– FFT averaging mode: linear averaging (stable mean)

2.3.5 The results shall be presented as weighted rms values in terms of vibration velocity.

Table 3.2 Required scope of vibration measurements, passenger and crew spaces, vertical direction

Verification percentages 1 Sea Mode

Harbour Operation

Thruster Operation

Aft of frame B

Passenger first-class cabins ≥ 50 –– ≥ 30 2

Passenger standard cabins ≥ 30 –– ≥ 30 2

Crew day and sleeping rooms ≥ 30 –– ≥ 30 2

Spaces between frame B and D

Passenger cabins, 1st class ≥ 20 –– ––

Passenger cabins, standard ≥ 10 –– ––

Crew day and sleeping rooms ≥ 10 –– ––

Spaces forward of frame D

Passenger cabins, 1st class ≥ 20 –– ≥ 30

Passenger cabins, standard ≥ 10 –– ≥ 30

Crew day and sleeping rooms ≥ 10 –– ≥ 30

1 For spaces not referred to in this table, C.2.2.5 and 2.2.6 applies.

2 For vessels equipped with stern thruster only.



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D. Survey Programmes

1. General

Different types of measurements which are to be con-ducted on board shall be described in six individual Survey Programmes:

Noise Vibration

Part I: Sea Mode Part V: Sea Mode

Part II: Harbour Operation Part VI: Thruster Operation

Part III: Thruster Operation

Part IV: Acoustic Privacy

At least three months prior to measurements the cor-responding Survey Programmes should be submitted to GL for approval.

All Survey Programmes shall be based on the final design stage of the ship and shall be presented in form of an A4-sized document with numbered pages. The use of A3 format is restricted to drawings.

Moreover, programmes are meant to give the persons performing measurements necessary background in-formation for a straightforward execution of meas-urements.

2. Data and drawings

2.1 Following items form the standard informa-tion required for approval of the Survey Programmes; additional documents can be required if deemed nec-essary.

2.2 General arrangement drawings of the ship (preferred scale 1:50, 1:100, 1:250 or 1:500).

2.3 Machinery arrangement drawings, including casing arrangement and machinery legend (preferred scale 1:100, 1:250 or 1:500).

2.4 Drawing for thermal, fire and sound protec-tion, including insulation details (e.g. sketches, mate-rial properties, etc.).

2.5 Floor and deck covering drawings (thermal, fire and sound protection), including insulation details (e.g. sketches, material and acoustical properties, etc.).

2.6 General arrangement drawings of mechanical ventilation systems, including location of HVAC rooms. All relevant structure-borne and airborne noise sources shall be indicated in the drawings (including the air supply / exhaust openings of mechanical venti-lation and HVAC systems).

2.7 Data and drawings required according to ISO 717-1 and ISO 717-2.

2.8 Acoustic privacy plan (see Annex B).

2.9 Detailed description (sketches, material prop-erties, etc.) of noise abatement measures which are provided in cabins adjacent to machinery spaces, cas-ings, trunks, etc.

3. Content of each survey programme

3.1 Target hcpass and hccrew

3.2 Ship particulars

3.3 Main data of propulsion plant, propeller, auxiliary engines.

3.4 Environmental conditions expected during measurements.

3.5 Permissible range of wind speed, sea state and water depth.

3.6 Operating conditions expected during meas-urements.

Loading condition, displacement, draughts, power and speed of main engine, propeller and auxiliary machin-ery.

3.7 Measurement instrumentation

3.8 Prepared measurement protocol sheets and sketches for each emission zone.

Table indicating for each measurement position: num-ber, location (frame, transverse offset from CL, deck level), measurement direction, kind and area [m²] of space/room and limit values corresponding to hc tar-get.

Measurement positions plotted in general arrangement plans indicating number, position and direction to be measured.

E. Survey Report

A Survey Report contains all results of each meas-urement on board, executed on the basis of the Survey Programmes.

Each Survey Report shall contain the following docu-mentation:

1. Ship and machinery data

2. Loading condition

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3. Any deviation from the Survey Programmes, e.g., environmental and operation condition, meas-urement locations, number, instrumentation etc.

4. Wind speed and direction, sea state (esti-mated wave height and direction), ship course and speed

5. Filled-in measurement protocol sheets for noise and vibration.

6. Calculation of overall hc achieved on the basis of measurement results.

7. All measured 1/1 and/or 1/3 octave band noise levels shall be submitted (CD, diskettes or via e-mail).

8. All measured vibration spectra shall be sub-mitted (CD, diskettes or via e-mail). The same applies to selected time series if desired by GL Surveyor.



E

Section 4

Calculation Procedure of hcClass_Notation

A. Determination of Single hc

The measured overall values for each individual meas-uring location during the acceptance tests (see Section 3) are transformed to the corresponding single hc on the basis of the limits given in Section 2.

The measurement values must not be rounded, i.e.:

– A measured noise level of 46,1 dB(A) exceeds a given limit of 46 dB(A).

– A measured vibration level of 3,21 mm/s exceeds a given limit of 3,2 mm/s.

B. Averaging of Single hc

All hc have to be determined separately for passenger and crew spaces.

For hcClass_Notation E, 1 and 2 the single hc must not exceed the desired hcClass_Notation by more than 2 cate-gories.

For hcClass_Notation 3 and 4 the measured noise and vi-bration levels must not exceed the respective limit values by more than 2 dB or 1,0 mm/s.

If the single hc is smaller than the desired hcClass_Notation, the latter must be used for the average hc calculation.

For vibration only: In a room/space with several measurement positions, the target hc shall not be ex-ceeded at more than one position.

1. Noise

1.1 The hcSPL_Cabins is defined as the arithmetic mean value (average hc) of all single hc determined during the required measurements for the sound pres-sure level in passenger and crew cabins, according to the following ranges:

hcSPL_Cabins = E for average hc = 0,00 to 0,25

hcSPL_Cabins = 1 for average hc = 1,00 to 1,25



hcSPL_Cabins = 4 for average hc = 4,00

1.2 The hcSPL_Others is defined as the arithmetic mean value (average hc) of all single hc determined during the required acceptance trials for the sound pressure level in passenger and crew spaces other than cabins, according to the following tolerances:

hcSPL_Others = E for average hc = 0,00 to 0,35

hcSPL_Others = 1 for average hc = 1,00 to 1,35



hcSPL_Others = 4 for average hc = 4,00

1.3 The hcAcoustic_Privacy is defined as the arithme-tic mean value (average hc) of all single hc determined during the required measurements for the sound and impact sound insulation, according to the following tolerances:

hcAcoustic_Privacy = E for average hc = 0,00 to 0,35

hcAcoustic_Privacy = 1 for average hc = 1,00 to 1,35



hcAcoustic_Privacy = 4 for average hc = 4,00

2. Vibration

2.1 The hcLongVib is the highest value of all sin-gle hc determined by measurements of the longitudinal vibrations during the required acceptance trials.

2.2 The hcTransvVib is the highest value of all sin-gle hcn determined by measurements of the transverse vibrations during the required acceptance trials.

2.3 The hcVertVib is defined as the arithmetic mean value (average hc) of all single hc determined by measurements of the vertical vibrations during the required acceptance trials, according to the following tolerances:

hcVert_Vib = E for average hc = 0,00 to 0,35

hcVert_Vib = 1 for average hc = 1,00 to 1,10



hcVert_Vib = 4 for average hc = 4,00

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C. Determination of hcClass_Notation

The hcClass_Notation is determined separately for passen-ger and crew spaces.

The hcClass_Notation is the highest value out of the fol-lowing six criteria, taking the three types of conditions into account (Sea Mode, Harbour Operation and Thruster Operation):

Noise: hcSPL_Cabins

hcSPL_others hcAcoustic_Privacy Vibration: hcLong_Vib

hcTransv_Vib

hcVert_Vib


Section 4 Calculation Procedure of hcClass_Notation I - Part 1GL 2004

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Annex A

Standards

A. General

1. If these Rules contain procedures deviating from the relevant standards, these Rules shall have priority.

B. Standards

1. Noise standards

– IMO Resolution A.468 (XII): 1982, "Code on noise levels on board ships"

– IMO Resolution A.343 (IX): 1975-11, "Rec-ommendation on Methods of Measuring Noise Levels at Listening Posts"

– ISO 2923, 1996-12, "Acoustics – Measurement of noise on board vessels"

– ISO 31-7: 1992-09, "Quantities and units of acoustics"

– IEC 651: 2001-10, Ed. 1.2, "Sound level metres"

– IEC 1260: 1995-08 and IEC 1260-am1: 2001-09, Electroacoustics - Octave-band and frac-tional-octave-band filters"

– IEC Publication 804, and amendment no. 1, 1989, "Integrating/averaging sound level me-ters"

– IEC 942: 1997-11, Ed. 2.0 and IEC 942-am1: 200-10, Ed. 2.0 "Sound calibrators"

– ISO 717/1: 1996-12, "Acoustics – Rating of sound insulation in buildings and of building elements – Part 1: Airborne sound insulation in buildings and interior elements"

– ISO 717/2: 1996-12, "Acoustics – Rating of sound insulation in buildings and of building elements – Part 2: Impact sound insulation"

– ISO 140/4: 1998-12, "Acoustics – Measurement of sound insulation in buildings and of building elements – Part 4: Field measurements of air-borne sound insulation between rooms"

– ISO 140/7: 1998-12, "Acoustics – Measurement of sound insulation in buildings and of building elements – Part 7: Field measurements of impact sound insulation of floors"

– ISO 1999: 1990-01, "Acoustics – Determination of occupational noise exposure and estimation of noise-induced hearing impairment"

– E DIN 45681: 1992-01, "Bestimmung der Ton-haltigkeit von Geräuschen und Ermittlung eines Tonzuschlages für die Beurteilung von Ge-räuschimmissionen" ("Detection of tonal com-ponents of noise and determination of a tone ad-justment for the assessment of noise imission")

2. Vibration standards

– ISO 6954: 2000E, "Mechanical vibration – Guidelines for the measurement, reporting and evaluation of vibration with regard to habitabil-ity on passenger and merchant ships"

– ISO 2631-1: 1997 (E), "Mechanical vibration and shock – Evaluation of human exposure to whole-body vibration – Part 1: General require-ments"

– ISO 2631-2: 1989 (E), "Mechanical vibration and shock – Evaluation of human exposure to whole – body vibration – Part 2: Continuous and shock induced vibration in buildings (1 - 80 Hz)"

– ISO 4867: 1984 (E), "Code for the measurement and reporting of shipboard vibration data"

– ISO 4868: 1984 (E), "Code for the measurement and reporting of local vibration data of ship structures and equipment"

– ISO 8041: 1990 (E), "Human response to vibra-tion – Measuring instrumentation"

– Germanischer Lloyd, Ed. 2004, "Rules for Clas-sification and Construction, I – Ship Technol-ogy, Part 1 –Seagoing Ships, Chapter 2 – Ma-chinery Installations"

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Annex A Standards Chapter 18Page A–1

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Annex B

Definitions

A. Important Definitions

– Angular frequency, circular frequency:

ω [rad/s] is the product of the frequency of a sinusoidal quantity and the factor 2 π:

ω = 2π ⋅ f

– Acoustic privacy:

"Privacy" from an acoustical point of view, i.e. the state of being alone and relatively undis-turbed with regard to noise emissions from neighbouring cabins, sanitary cells, corridors, public spaces, open deck recreation spaces, ser-vice spaces, etc. (sound and impact sound insu-lation).

– Acoustic privacy plan:

Drawings showing the arrangement of all cabin types including noise limit values to be kept. See also "cabin type".

– Auxiliary machinery:

Machinery, other than main propulsion machin-ery, operating when the ship is in normal ser-vice, e.g. auxiliary diesel engines, turbo-generators, hydraulic motors and pumps, com-pressors, boilers, ventilation fans, gears, pumps.

– Abatement measures:

Noise and/or vibration control measures, e.g. with the aim of reducing the airborne and/or structure-borne noise emission as well as of vi-bration levels of structures, equipment, etc.

– A-weighted sound pressure level LAeq or LAeq,T:

The A-weighted equivalent continuous sound pressure level using the frequency weighting "A" as specified in the IEC publication 60651 within a measurement time interval T.

– Beat, beating:

Periodic amplitude variations of an oscillation resulting from the superposition of two excita-tion sources of slightly different frequencies. Beating which occurs in the audible frequency range is experienced as being annoying.

– Boom, booming: Deep, hollow resonant low-frequency sound in

the range between 16 and 125 Hz. Booming is mainly due to one or more discrete tonal com-ponents of significantly greater amplitudes than

those of the adjacent spectrum level. Booming is experienced as being annoying and can only be detected subjectively. See also "steady noise with audible discrete tones".

– Booming rating procedure:

Procedure for measuring and assessing the oc-currence of audible discrete tones below 125 Hz (booming effect). The procedure developed by GL is based on experimental investigations on board ships.

As result of this procedure a booming adjust-ment (CB in dB(A)) is established. The noise rating level has to be used for further evaluation.

– Bathroom:

A room in which there is, e.g. a shower and/or a bathtub, a washbasin, a toilet, etc. In these Rules, the area of a bathroom is greater than 6 m2.

– Cabin type:

Cabins with different types of interior systems (lining walls, ceilings, doors, etc.), floor con-structions, floor coverings, etc. See also "Acous-tic privacy plan".

– Crew spaces:

Cabins, offices (for carrying out the ship's busi-ness), hospitals, mess rooms, recreation rooms (such as lounges, smoke rooms, cinemas, librar-ies, hobby and game rooms) and open recreation areas used by officers, hotel staff and crew.

– Corridors:

Passageways/alleyways arranged in crew and passenger spaces.

– Depth Froude Number:

The Depth Froude Number is v g h⋅ ; v = ship speed [m/s], g = gravitation accelera-tion [m/s2], h = water depth [m].

– Displacement Δ:

Displacement of the vessel [t].

– Dressing-room:

A room for putting on clothes and a place where clothes are stored, usually in a built-in ward-robe. In these Rules, the area of a dressing room

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Annex B Definitions Chapter 18Page B–1

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is greater than 8 m2. Otherwise the dressing room is not to be defined as a "room".

– Driving–point impedance:

In a mathematical sense, the complex ratio of force to velocity taken at the same point in a mechanical system during simple harmonic mo-tion.

– Engine or shaft speed:

Number of revolutions per minute [rpm]

– Equivalent continuous sound pressure level Leq or Leq,T :

Unweighted sound pressure level of a continu-ous steady sound. Within a measurement time interval T this sound has the same mean square sound pressure as a sound under consideration that varies with time. It is expressed in decibels by the following equation:

( )

( ) 2t2eq eq,T 10

2 1 t o1

p t1L = L = 10 log dtt - t p

⎡ ⎤⎛ ⎞⎢ ⎥⋅ ⋅ ⋅∫ ⎜ ⎟⎢ ⎥⎝ ⎠⎣ ⎦

(t2 – t1) = period T over which the average is taken, starting at t1 and ending at t2

p (t) = unweighted instantaneous rms sound pressure between 16 and 16 000 Hz

p0 = 2 ⋅ 10–5 Pa (reference level)

– Exposure time (vibration):

A distinction is made as to whether public spaces are characterized by "short" or "long" exposure times. Typical public spaces with short exposure times are receptions, shops, alleyways, staircases, lobbies, sanitary rooms, etc. Typical public spaces with long exposure times are res-taurants, cafeterias, bars, theatres, cinemas, lounges, conference rooms, hospitals, discos, etc.

– Fluctuating noise:

The measured sound pressure level (e.g. pointer of the display) varies more than ± 3 decibels with the "slow" meter characteristic switched on. Impulse noise must be excluded.

– Frame A, B, C, D:

See "imission zones"

– Hard floor:

Floor characterized by a relatively "hard" final covering, e.g. uncovered steel deck, wood, tiles, marble, PVC, etc. fitted on top of floating floors, viscoelastic floors, normal deck components, steel decks, etc.

– Hotel staff spaces:

See "crew spaces"

– HVAC:

Heating, venting and air-conditioning system

– Imission zones:

Typical noise and vibration imission zones are defined as follows:

– Frame A:

A virtual frame section at a maximum dis-tance of 3 times the propeller diameter in front of the propeller plane.

– Frame B:

A virtual frame section or the aft main vertical fire zone bulkhead at a distance of at least 0,15 Lpp in front of the propeller plane.

– Frame C:

Forward bulkhead of forward engine room (main or auxiliary diesel engine room).

– Frame D:

20 m aft of rear bulkhead of bow thruster room.

– Impedance:

See "driving-point impedance"

– Impulse noise:

Noise of less than one second duration that oc-curs as an isolated event or as one of a series of events with a repetition rate of less than 15 times per second. The presence of impulse noise shall be determined by obtaining the dif-ference between the equivalent continuous sound pressure level measured with time weighting "impulse" and "fast". If the difference is more than 2 dB, the presence of impulse noise may be assumed.

– Impulse rating procedure:

Procedure for measuring and assessing the oc-currence of impulse noise events. As result of this GL procedure an impulse adjustment CI [dB(A)] is established. The noise rating level has to be used for further evaluation.

– Integrating sound level meter:

A sound level meter designed or adapted to measure the level of the mean squared time av-eraged A-weighted sound pressure level (IEC 804).

– ISO noise rating (NR) number:

The number found by plotting the 1/1 octave band spectrum of the NR curves given in ISO

Chapter 18 Page B–2

Annex B Definitions I - Part 1GL 2004

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Standard R 1996-1967 and selecting the highest noise rating curve tangent to the spectrum.

– Machinery spaces:

All spaces containing propulsion machinery, boilers, steam and internal combustion engines, generators and major electrical machinery, oil filling stations, refrigerating, stabilizing, hydrau-lic units, air-conditioning cooling compressors, etc.

– Maximum continuous rating (MCR):

Designed maximum continuous power rating of main engines.

– Measured SPL:

The sound pressure level measured with a sound level meter or sound measurement instrumenta-tion. The measured SPL shall be expressed to one decimal place.

– Net living space:

Total living area of an individual pax cabin without sanitary cell and balcony in square me-tres.

– Noise level:

See "A-weighted sound pressure level".

– NRC:

Noise rating curve, see "ISO noise rating (NR) number".

– Noise rating level:

The noise rating level LA, r is defined as follows:

LA,r = Aeq T I BL C C C+ + + [dB(A)]

= noise rating level [dB(A)]

LAeq = measured overall A-weighted sound pressure level

CT, CI, CB = adjustments as result of the tone, impulse and booming rating pro-cedure

– Noise FEM:

The Noise Finite Element Method (Noise FEM) developed by Germanischer Lloyd makes it pos-sible to predict the propagation of structure-borne noise energy in complex ship structures. For this purpose the Noise FEM uses the geome-try and material data of existing global finite element models created mainly for strength and vibration computations. Noise FEM is based on principles also used in SEA. For detailed infor-mation see:

C. Cabos and H. G. Matthies: "A method for the prediction of structure-

borne noise propagation in ships", Proceed-ings of the 6th international congress on

sound and vibration 1999, Technical Univer-sity of Denmark

– Normal service speed: Shaft speed and propulsion power correspond-

ing to service speed contractually agreed on, at least at 85 % MCR.

– Officers' spaces: See "crew spaces".

– Overall frequency-weighted rms value:

The overall frequency-weighted rms value has to be determined according to ISO 6954, second edition 2000-12-15.

– Overhang:

An overhang in this context is the part of a deck area protruding the vertical support (walls, pil-lars).

– Passenger:

Any person on board other than members of the crew or persons employed or engaged in any ca-pacity for the business of that ship.

– Pax cabins:

All types of cabins (e.g. suite, first-class, stan-dard cabin, etc.) intended to be used by passen-gers.

– Passenger indoor spaces:

All areas used by passengers in enclosed spaces of the vessel.

– Passenger outdoor spaces:

All outdoor recreation areas to where passenger access is foreseen.

– Public spaces, type 1: Enclosed spaces for passenger recreation where

the noise level normally is or may be high when in use, e.g. entertainment spaces such as discos, theatres, cinemas, gymnasiums, dance floors, stages, etc.

The sound pressure levels for the 1/1 octave band mid frequencies that should not be ex-ceeded in above spaces are listed in Table B.1.

– Public spaces, type 1a:

Separated deck/floor spaces of public spaces type 1 such as dance floors, stages and gymna-sium floors.

– Public spaces, type 2: Enclosed spaces for passenger recreation where

the noise level is not normally high (approx. 75 dB(A) or can be expected to be low (approx. 65 dB(A)) when in use, e.g. conference rooms, casinos, restaurants, bars, shops, atriums, galler-ies, receptions, observation lounges, libraries, etc.

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Annex B Definitions Chapter 18Page B–3

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Table B.1 Sound pressure levels for public spaces type 1

1/1 octave band limit value 1/1 octave band limit value

31,5 Hz 65 dB(A) 1 000 Hz 91 dB(A)

63 Hz 72 dB(A) 2 000 Hz 94 dB(A)

125 Hz 78 dB(A) 4 000 Hz 94 dB(A)

250 Hz 85 dB(A) 8 000 Hz 94 dB(A)

500 Hz 88 dB(A) –– –––

– RMS value: The rms value of a single-valued function, f(t),

over an interval between t1 and t2 is

( )

1 2t2 2t1

2 1

f t dtrms value

t t

⎡ ⎤∫⎢ ⎥

= ⎢ ⎥−⎢ ⎥

⎢ ⎥⎣ ⎦

– Room space:

Total room area of an individual public space [m2]

– SEA:

Statistical Energy Analysis. For detailed infor-mation see:

R. H. Lyon and R. G. DeJong,

"Theory and Applications of Statistical En-ergy Analysis", Butterworth Heinemann, Boston 1995

– Soft floor:

Floor characterized by a relatively soft final covering, e.g. carpets, carpeting, etc., fitted on top of floating floors, viscoelastic floors, nor-mal deck compounds, steel decks, etc.

– Sound pressure level "L":

A measure of sound level on logarithmic scale given by:

[ ]100

pL 20 log dBp

⎛ ⎞= ⋅ ⎜ ⎟

⎝ ⎠

where:

p = rms value of measured sound pressure between 16 and 16 000 Hz

p0 = 2 ⋅ 10–5 Pa reference level

– Steady noise without audible discrete tones:

Level fluctuations equal to or less than ± 3 decibels. This type of noise is frequently re-ferred to as "broad-band" noise. Obvious tonal components of noise (tonality and/or booming) in the whole audible frequency range between

16 and 16 000 Hz are absent or negligibly small.

– Steady noise with audible discrete tones:

This type of noise has components at one or more discrete frequencies having significantly greater amplitudes than those of the adjacent spectrum level. Audible discrete tonal compo-nents of noise (tonality and/or booming) can occur in the whole audible frequency range be-tween 16 and 16 000 Hz.

– Sanitary cell:

A space in which there is, e.g. a shower and/or bathtub, a washbasin, a toilet, etc. In these Rules, the room space of a sanitary cell is less than or equal to 6 m2. Sanitary cells are not de-fined as "rooms".

– Suite:

First-class passenger cabin/space with a set of at least two adjacent rooms, e.g. bedroom, liv-ing room and/or sitting room, bathroom, dress-ing room, etc.

– Tonality, annoying discrete tone:

A sound wave whose instantaneous sound pressure varies essentially as a simple sinusoi-dal function of time (pure tone). Tonality is ex-perienced as being annoying and can only be detected subjectively. Tonality is defined in the frequency range between 125 and 16 000 Hz. It is mainly caused by main reduction gears, pumps, air-conditioning cooling compressor units, thruster gears, HVAC inlet and outlet openings, etc.

– Tone rating procedure:

Procedure for measuring and evaluating the occurrence of tonality. It was developed by Germanischer Lloyd on the basis of national standards and experimental investigations on board ships.

As a result of this procedure, a tone adjustment figure CT [dB(A)] is established. The noise rat-ing level has to be used for further evaluation.

Chapter 18 Page B–4

Annex B Definitions I - Part 1GL 2004

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Annex C

Recommendations to Reduce Noise and Vibration

A. General

1. To maintain the required noise and vibration levels, various investigations and noise and vibration reduction measures are recommended. This is true for the planning, design, fabrication and testing phase of a newbuilding.

B. Considerations Regarding Excitation Forces

By nature, the reduction of noise and vibration excita-tion forces is the most effective way to reduce the noise and vibration levels. Therefore it is recom-mended: – to optimise the ship's lines by model tests in

order to achieve an appropriate wake distribu-tion

– to optimise the propeller design with regard to noise and vibration excitation by cavitation tank tests

– to take into account the noise and vibration excitation characteristics of main and auxiliary machinery, gear, bow thruster, etc. by adequate choice of suppliers

C. Theoretical Investigations

1. Noise and vibration aspects should be con-sidered as early as possible in the design process.

2. The extent of theoretical investigations nec-essary depends on the experience of the yard with the relevant ship type and the hc which shall be achieved. As a guideline the analyses summarised in Table C.1. are recommended.

The following types of investigations are distin-guished:

Review of General Arrangement Plan

Prior to detailed investigations, the general arrange-ment plan is reviewed with regard to noise and vibra-tion.

Local Vibration Calculation

Natural frequencies of plate fields, stiffeners and small regularly stiffened panels are estimated by means of

empirical formulas. The objective is to avoid reso-nance with main excitation frequencies. Added masses as well as hydrodynamic masses have to be consid-ered. Attention should especially focus on local struc-tures in vicinity of excitation sources (e.g. main pro-pulsion, bow and stern thrusters) as well as on struc-tural components of public, living and working spaces. Natural frequencies of all structural components shall be chosen to have a sufficient margin to main excita-tion frequencies.

Noise Prediction

A noise prediction is conducted at an early design stage. Semi-empirical noise prediction programmes are applied to predict the average airborne noise lev-els. Noise limits specified for passenger and crew spaces are compared with predicted values.

Global Vibration Level Prediction

In a global vibration level prediction, the vibration level at "global" points of the ship structure is esti-mated on the basis of a forced vibration calculation in the lower frequency range (approx. 1 Hz to 20 Hz). Dynamic magnification due to local resonances of plate fields, stiffeners or panels is not considered. These local structural systems are investigated sepa-rately (see "Local Vibration Calculation").

The vibration level is estimated for relevant loading conditions at representative points of the ship struc-ture.

If the expected vibration level exceeds specified lim-its, modifications of the steel structure, a different number of propeller blades, arrangement of compensa-tors, etc. are proposed as possible means of improve-ment.

Detailed Vibration Level Prediction

A detailed vibration level prediction represents an extension of a global vibration level prediction, i.e. the dynamic magnification due to vibrations of large deck panel structures is considered. The distribution of homogeneous and inhomogeneous masses on decks is taken into account as realistically as possible.

Detailed Impedance Investigation

Driving-point impedance levels (frequency range approx. 50 to 300 Hz) of machinery foundations, shell constructions above the propeller and of other critical areas are determined by means of detailed local finite element models as early as possible during the design stage. The aim of such an investigation is to optimize relevant parts of the ship structure from an acoustical point of view.

I - Part 1 GL 2004

Annex C Recommendations to Reduce Noise and Vibration Chapter 18Page C–1

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NoiseFEM Analysis / Statistical Energy Analysis (SEA)

With a SEA or a NoiseFEM analysis, the sound propagation within the structure is predicted. Consid-ering the main structural members, the structure-borne noise intensity flow is calculated for each subsystem of the SEA/NoiseFEM model. Then the energy level within each subsystem is used for predicting average structure-borne and airborne noise levels in the ship.

D. Secondary Measures

1. If the theoretical investigations reveal that the required noise and vibration levels probably can not be attained secondary measures should be foreseen, i.e.:

– isolation (resilient supports for instance)

– insulation, encapsulation

– damping (floating floors for instance)

– compensation of vibration excitation forces

– silencing

– structural modifications

E. Supplementary Measurements during Production Phase

1. It is recommended to carry out test bed noise and vibration measurements for the machinery com-ponents in order to check the adherence to noise and vibration specifications agreed on with suppliers.

2. During outfitting stage the local vibrations of deck structures should be measured (impact or/and exciter measurements) to verify calculation results and to identify and rectify local structural deficiencies.

3. During outfitting stage the impedance of machinery foundations should be measured to verify cal-culation results and to identify and rectify local struc-tural deficiencies.

Table C.1 Recommended theoretical investigations for seagoing cruise ships (v > 25 knots)

Seagoing passenger ships

hc

Type of investigation

E 1 2 3 4

Review of General Arrangement 1

Local Vibration Calculation

Noise Prediction 1

Global Vibration Level Prediction

Detailed Vibration Level Prediction

Detailed Impedance Investigation

Detailed Noise Analysis (e.g. NoiseFEM Analysis, SEA Analysis etc.) 1

= Strongly recommended = Recommended

= Recommended only if experience with similar ships is not available 1 The occurrence of tonality and/or booming in pax cabins and public spaces will be strictly assessed for hc E to 2

(see Section 3, C.1.3.4).

Chapter 18 Page C–2

Annex C Recommendations to Reduce Noise and Vibration I - Part 1GL 2004

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Annex D

Protocol Sheet

A. Measurement Protocol Sheet

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I - Part 1 GL 2004

Annex D Protocol Sheet Chapter 18Page D–1

A

GLRP - Content(I-1-18) Harmony Class Œ Rules on Rating Noise and Vibration for Comfort, Cruise Ships (v > 25 kn)Section 1 ClassificationA. ScopeB. Harmony Criteria Numbers (hc)C. Class Notation

Section 2 Required Noise and Vibration LimitsA. GeneralC. Vibration Requirements

Section 3 Required MeasurementsA. GeneralB. Measuring ConditionsC. Performance of MeasurementsD. Survey ProgrammesE. Survey Report

Section 4 Calculation Procedure of hcClass_NotationA. Determination of single hcB. Averaging of single hcC. Determination of hcClass_Notation

Annex A StandardsA. GeneralB. Standards

Annex B DefinitionsA. Important Definitions

Annex C Recommendations to Reduce Noise and VibrationA. GeneralB. Considerations Regarding Excitation ForcesC. Theoretical InvestigationsD. Secondary MeasuresE. Supplementary Measurements during Production Phase

Annex D Protocol SheetA. Measurement Protocol Sheet

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