DI-017_REV_2_AIRBORNE_NOISE_REPORT.pdf
PDF 2 MB Posted
- Attached to
- NPS ISRO Ranger IV Vessel
- Solicitation number
- 140PS125R0009
About this file
This document is a DI-017 Airborne Noise Report for the preliminary/contract design of Motor Vessel Ranger IV, prepared by PZdynamics Ltd for RRP Consulting Engineers. The noise analysis assesses the vessel's noise and vibration characteristics across multiple decks and spaces, evaluating compliance with ABS (American Bureau of Shipping) crew habitability and passenger comfort notation requirements for HAB, HAB+, and HAB++ standards.
The comprehensive report reveals that the Ranger IV design meets the ABS "HAB" notation requirements and exceeds HAB+ standards in most spaces. Without special noise mitigation measures, only cabins on the 2nd deck at frames 50 and 45 fall slightly short of HAB+ requirements. When implementing floating floors, almost all spaces can achieve HAB++ standards, with the exceptions being the 2nd deck cabins at frames 50 and 45 and passenger deck aft sanitary spaces. The analysis includes detailed noise simulations considering propeller structure-borne noise, gearbox structure-borne noise, and airborne noise from sources like engines, exhaust systems, and ventilation, providing a thorough acoustic performance assessment of the vessel design.
View the file
Other files
Show 40 more
Latest 50 of 68 listed here. See the rest on GovTribe.
On GovTribe
Work with this file
- Download the original file
- Contacts named in this file
- Similar government files
- Ask GovTribe AI about this file
Text version
DI-017 Airborne Noise Report Contract 6913G623P800007
Preliminary/Contract Design of Motor Vessel Ranger IV
Submitted by:
Loch Harbour Group
3060 Williams Drive, Suite 510
Fairfax, Virginia 22031
Preliminary/Contract Design of Motor Vessel Ranger IV
Contract No.: 6913G623P800007
CLIN-00100
DI-017 Airborne Noise Report Revision 2
Submittal Date: August 28, 2024
DISTRIBUTION Statement C: Distribution authorized to the U.S. Government agencies and their Contractors. Other request for this document shall be referred to the US Department of Transportation Volpe Center.
DATA RIGHTS: This report, drawing, design, concept, and specification are the intellectual property of Loch Harbour
Group, LLC, and/or R.R.P CONSULTING ENGINEERS, L.L.C and contain information which is proprietary. The rights defined below are reserved by Loch Harbour Group, LLC, and/or R.R.P CONSULTING ENGINEERS, L.L.C.
The United States Government’s rights to use, modify, reproduce, release, perform, display, or disclose these technical data are unrestricted. Any reproduction of technical data or portions thereof marked with this legend must also reproduce the markings.
PZdynamics Website: www.pzdynamics.com Email: info@pzdynamics.com Tel: +44(0)7500478243
1 | P a g e
DI-017 NOISE PREDICTION REPORT
Ranger IV
08-28-2024
A report written by PZdynamics Ltd for RRP Consulting Engineers
Dr. P.G. Zoet http://www.pzdynamics.com/
Email: info@pzdynamics.com
2 | P a g e
Contents
1. Summary and conclusions
2. Report content
3. Noise limits
4. Noise sources and transmission paths
5. Airborne noise analysis
6. Structure borne noise
7. Presentation of total noise levels
Appendix I: Engine and exhaust source levels
Appendix II: Airborne noise spectra
LIABILITY
PZdynamics has used reasonable endeavours to ensure an accurate assessment of the vibrations and noise investigated in this report, but PZdynamics makes no warranty, expressed or implied, as to accuracy and accepts no responsibility for any use by RRP Consulting Engineers of the Deliverables or PZdynamics Intellectual Property, nor for any reliance placed by RRP
Consulting Engineers, on the Deliverables or PZdynamics Intellectual Property, nor for advice or information given in connection with a Project.
RRP Consulting Engineers will indemnify PZdynamics and keep it fully and effectively indemnified against each and every claim made against PZdynamics as a result of RRP Consulting Engineers use of any of the Deliverables or PZdynamics
Intellectual Property received through this report.
Email: info@pzdynamics.com
3 | P a g e
1. Summary and conclusions
As part of the Work Authorisation subcontract no. LA2301-Z0001, the conclusions of the noise analysis for the passenger vessel Ranger IV are as follows:
The Noise and Vibration analysis shows that the Ranger IV design meets the ABS class requirements of notation "HAB" and also exceeds the requirements for HAB+, and HAB++ in most spaces / locations.
Without special measures (such as floating floors), all spaces are fulfilling HAB+ requirements except for Cabins on the 2nd deck, at frame 50 and 45 (see Figure 1 marked with red). Hence, no modifications are considered necessary to obtain ABS “HAB” notation, but the recommendations are suggested only to improve the comfort levels.
When applying a floating floor, all spaces can also be able to fulfil HAB++ except for below two spaces which fulfil HAB+ requirements:
- Cabins deck 2 frame 50 and 45
- Passenger deck aft sanitary spaces.
See section 7 and appendix II for details.
Figure 1 Total results noise simulations Ranger IV.
Email: info@pzdynamics.com
4 | P a g e
2. Report content
This report represents the deliverable DI-017 as per Authorisation subcontract no LA2301-Z0001 representing the full noise analysis for the passenger vessel Ranger IV.
This report outlines the noise requirements (section 3), description of noise sources and transmission paths (section 4) and analysis results of airborne noise (section 5), structure borne noise (section 6) and finally the total noise levels (section 7).
3. Noise limits
Noise requirements according to the ABS Guide for Crew Habitability on Ships and ABS Guide for
Passenger Comfort on Ships to obtain “HAB” notation are to be fulfilled.
Acoustic limit values are presented both for the overall A weighted noise levels (see Figure 3) as well as isolation properties of noise between spaces.
The airborne sound insulation properties for bulkheads and decks within the accommodation shall comply at least with the following weighted sound reduction index (Rw) according to ISO Standard
717-1:2013:
Figure 2 Insulation requirements according to ISO 717-1:2013
Email: info@pzdynamics.com
5 | P a g e
Figure 3 Limit values overall A weighted levels
Email: info@pzdynamics.com
6 | P a g e
4. Noise sources and transmission paths
On behalf of RRP Consulting Engineers, PZdynamics has performed a noise and vibration prediction calculations for their design of the Ranger IV passenger vessel.
The analysis consists of the following parts:
- Prediction of airborne noise propagation: Areas most affected by airborne noise are areas adjacent to machinery spaces and exhaust pipes. Sources of airborne noise are:
o Main and auxiliary engines o Exhaust noise (inside casing and noise radiated to aft ship) o HVAC noise through air duct o Ventilation noise ER
- Prediction of structure borne noise from gearboxes and propellers.
When it comes to airborne noise, insulation properties between spaces also need to be considered from the point of view that transmission of noise generated by people’s activities from one space to another need to be reduced by applying sufficient insulation on bulkheads.
The supplier of the cabin partition panels will be able to tell if the panels fulfil the requirements in
Figure 2.
Email: info@pzdynamics.com
7 | P a g e
5. Airborne noise analysis
For the airborne noise transmission and room acoustic calculation, procedures have been used as per
ABS guidelines taking into consideration typical absorption values for steel and applied isolation materials and impact of sizes of the spaces in relation to the transmission surface areas.
Transmission of noise through bulkheads has been calculated as function of frequency using the appropriate equations for sub critical, critical, and super critical (mass law) behaviour of partition panels/bulkheads.
The following information is listed of the main noise sources:
Figure 4 General information diesel engines and propellers
Email: info@pzdynamics.com
8 | P a g e
Areas mostly affected by airborne noise transmission are the areas closest to the engine room and exhaust casing as shown in Figure 5. These areas are:
- 2nd deck locker room and corridor adjacent to the engine room bulkhead (frame 55)
- Main deck cargo space adjacent close to the engine room casing bulkhead (frame 55)
- 01 level sanitary spaces adjacent to engine room casing bulkhead (frame 55)
Figure 5 Summary of air borne noise transmission calculation results. Results have been calculated based on maximum engine power output (see appendix I) using isolation values as shown in Figure 6.
In the calculations typical values have been used for rockwool isolation materials typically used in engine rooms/casings and materials as typically wrapped around the exhaust pipes. See appendix II for details.
Engine room
Exhaust casing Affected area limit values storeroom: 70 dB
Calculated noise level: 58.2 dB(A)
Affected area corridor and locker room.
Limit value = 70 dB value: 60 dB(A)
Exhaust casing Affected area limit values sanitary spaces: 55 or 60 dB level = 53.7 dB(A)
Email: info@pzdynamics.com
9 | P a g e
Figure 6 Properties used for isolation materials on engine room bulkhead frame 55 (top left), around exhaust pipe
(top right) and as panelling on the bulkheads at frame 55 on the main deck and deck level 01 (bottom). No silencer has been applied on the diesel engines
Email: info@pzdynamics.com
10 | P a g e
6. Structure borne noise
Contribution of structure borne noise to the total noise levels of the vessel has been calculated using empirical equations based on propeller properties, and properties of the gear box. The estimation has been made for the cabin closets to the propeller/gearboxes. Figure 7 shows an example of how structure borne noise has been calculated for the structure borne noise most critical area, which is around the most aft cabins on the 2nd deck.
Figure 7 Estimation of structure borne noise in the most aft cabin.
Email: info@pzdynamics.com
11 | P a g e
7. Presentation of total noise levels
Adding both airborne and structure borne noise levels together gives the following total results (see also appendix II)
Figure 8 Calculated total noise levels (top) and calculation of allowable background noise (air conditioning being the most dominant likely source) in case either HAB+ needs to be fulfilled or HAB++.
Email: info@pzdynamics.com
12 | P a g e
Figure 9 Location for which noise levels have been calculated
Email: info@pzdynamics.com
13 | P a g e
Appendix I
Engine and exhaust noise source data
Email: info@pzdynamics.com
14 | P a g e
Email: info@pzdynamics.com
15 | P a g e
Appendix II
Airborne Noise spectra
Email: info@pzdynamics.com
16 | P a g e
Email: info@pzdynamics.com
17 | P a g e
Email: info@pzdynamics.com
18 | P a g e
Email: info@pzdynamics.com
19 | P a g e
Email: info@pzdynamics.com
20 | P a g e
Email: info@pzdynamics.com
21 | P a g e
Email: info@pzdynamics.com
22 | P a g e
Email: info@pzdynamics.com
23 | P a g e
Email: info@pzdynamics.com
24 | P a g e
Email: info@pzdynamics.com
25 | P a g e
Email: info@pzdynamics.com
26 | P a g e
Email: info@pzdynamics.com
27 | P a g e
Email: info@pzdynamics.com
28 | P a g e
Email: info@pzdynamics.com
29 | P a g e
Email: info@pzdynamics.com
30 | P a g e
Email: info@pzdynamics.com
31 | P a g e
Email: info@pzdynamics.com
32 | P a g e
Email: info@pzdynamics.com
33 | P a g e
Email: info@pzdynamics.com
34 | P a g e
Email: info@pzdynamics.com
35 | P a g e
Email: info@pzdynamics.com
36 | P a g e
DI-017_Airborne Noise Report_Rev2_Cover
File details come from the government source that posted it. Updated .