DI-HFAC-81278A

Airborne Noise Analysis and Control Design History Booklet

The Airborne Noise Analysis and Control Design History Booklet documents the Contractor's noise analysis, noise control design, and quality assurance inspection efforts to demonstrate compliance with requirements of MIL-STD-1474.

Approval DateApril 13, 2015

AMSC NumberN9538

Preparing ActivitySH

Project NumberHFAC-2015-012

OPR—

DTIC ApplicableNo

GIDEP ApplicableNo

Limitation—

Applicable Forms—

Approval Limitation—

Form Version—

DID Formatfree_text

963C CompliantYes

DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.

Supersedes

DI-HFAC-81278

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Description & Purpose

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Application & Interrelationship

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Use & Relationship

a. This Data Item Description (DID) contains the format, content, and preparation instructions for the data generated in response to the applicable tasks in MIL-STD-1474 and ANSI/ASA S12.67, Pre-Installation Airborne Sound Measurements and Acceptance Criteria of Shipboard Equipment.

b. This DID shall be applied for each noise grade, class, rating, and type of equipment to be tested for airborne noise performance when MIL-STD-1474 and ANSI/ASA S12.67 is invoked in the contract specification or statement of work.

c. This DID supersedes DI-HFAC-81278.

Preparation Instructions

1Reference documents.The applicable issue of the documents cited herein, including their approval dates and dates of any applicable amendments, notices, and revisions shall be as specified in the contract.

2Format.The Airborne Noise Analysis and Control Design History Booklet shall be in the Contractor's format.

3Content.The Airborne Noise Analysis and Control Design History Booklet shall contain the following:

3.1Noise limits for compartment, on-deck stations, and the ship operating condition(s) during which the noise limits apply including underway at speed and when dockside. Special considerations such as ship noise at a distance shall be identified, if applicable.

3.2The title, Naval Sea Systems Command (NAVSEA) identifying number, and revision number of ship drawings, i.e., general arrangement for the following used to develop predicted noise levels:

3.2.1machinery arrangement

3.2.2insulation arrangement and details

3.2.3joiner arrangement and details

3.2.4heating, ventilation, and air conditioning (HVAC) arrangement and details

3.2.5piping system arrangements and details

3.2.6diesel exhaust system arrangements and details

3.3The Booklet shall contain a description of the analysis procedures used to predict compartment and on-deck station dB(A) and octave band noise levels.

3.4Octave band noise predictions and the A-weighted overall noise predictions, for each compartment and on-deck station assigned a noise criterion (limit); and predicted time weighted average (TWA) noise levels, as applicable shall be included.

3.5The Booklet shall include a listing of the octave band noise source levels assigned to machinery items, equipment items, and fans including airborne noise source levels and structureborne noise source levels; and an explanation of how the noise source levels were derived.

3.6A listing of the octave band sound transmission, radiation efficiency, and attenuating properties of ship constructions encountered in the predictions including, as applicable,

3.6.1bare bulkheads

3.6.2bulkheads with noise control treatments, thermal treatments, and sheathing applied

3.6.3bulkheads when covered with joiner linings

3.6.4decks when covered with floating floors, suspended ceilings, or insulations

3.6.5mounting system transmission losses

3.6.6lined and unlined ducts

3.6.7acoustic enclosures, barriers, and plena

3.7The Booklet shall include a listing of the following:

3.7.1machinery

3.7.2propulsors

3.7.3equipment

3.7.4contractor furnished equipment (CFE)

3.7.5government furnished equipment (GFE)

3.7.6piping system

3.7.7HVAC system noise contributions

3.7.8the combined overall resultant predicted noise levels for each compartment and on-deck station that is assigned a noise criterion (limit)

3.8Where noise level measurement locations are known, the Booklet shall include the predictions for reverberant and direct field noise contributions. If more than one noise measurement condition (ship operating state) is specified, the Booklet shall also include predicted noise levels for each condition.

3.9A listing of assumptions used in developing the noise predictions and a justification for each assumption shall be included.

3.10Noise levels and noise excesses, predicted on a compartment-by-compartment basis, applicable to the ship design and ship operating state prior to the inclusion of additional noise control measures beyond those explicitly identified in the ship specification shall be included.

3.11A description of the analysis procedures for computing personnel TWA exposures if noise excess or hazardous conditions are predicted or reported.

3.12The Booklet shall include design recommendations and options for additional noise control measures beyond those explicitly identified in the ship specification which, if implemented, are predicted to eliminate noise excesses and shall also include:

3.12.1A table listing which machinery and equipment items including piping systems will be installed on resilient mounts (single or compound), mounting system type (low natural frequency or distributive isolation material), mount make and model number, and the number of mounts that will be installed per machinery item or equipment item.

3.12.2References to drawings identifying specific make, model, and type in reference to the following:

3.12.2.1insulations recommended for noise control and areas of coverage

3.12.2.2damping materials recommended for noise control and areas of coverage

3.12.2.3floating floors recommended for noise control and areas of coverage

3.12.2.4machinery items and pipe systems to be mounted resiliently

3.12.2.5HVAC drawings showing sections of duct fitted with linings or laggings that are recommended for noise control showing areas of coverage

3.12.2.6any special noise control measures such as relocation of compartments, inclusion of barriers, acoustic enclosures, mufflers, cords, flexible hose or bellows assemblies, pulsation dampers, high impedance foundations, compound mounting systems, and high sound transmission loss doors and windows

3.13The Booklet shall include a list of references that identify reports containing analysis and design information for noise control measures.

3.14The Booklet shall cite any diesel exhaust system mounting analyses and design studies to ensure proper loading, resonance avoidance, and evaluation of thermal exposure in cases where elastomeric mounts are used.

3.15A list of compartments and on-deck stations experiencing measured noise excesses resulting from ship trials, recommendations for newly identified additional noise control measures to eliminate measured excesses, and revised noise (octave band and overall A-weighted) predictions assuming the inclusion of the newly identified additional noise control measures and materials into the ship design. Impacts on design and cost shall be included.

References

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