Among the possible solutions to meet the vibration requirements are:
The noise treatments discussed above are not the only ones available in the marketplace. There also are possible applications of noise-canceling technologies from other industries for the marine industry such as active mufflers, active mounts, noise-canceling quiet zones, and noise-canceling headsets. (Dev 2017).
There is a close relationship between the vibrations of structures and the ship’s acoustics, hence some of those solutions for noise can also be used to satisfy the vibration requirements, especially for structure-borne noise. The vibration-reducing approaches include:
All the approaches above are meant to reduce noise and vibration hazards for passengers and crew. By meeting and, where possible, exceeding the mandatory and voluntary guidelines, ship builders, owners, and operators can ensure that their seafarers will have excellent accommodation and recreational facilities on board that are also consistent with promoting the safety, health and well-being of all on board. This goal is one of Bering’s very highest priorities. The efforts and measures Bering takes when it comes to acoustic and vibration harm prevention and the results of independent evaluation of these efforts are outlined in the next chapter.
All yachts constructed by Bering Yachts go through a rigorous procedure of noise and vibration prevention design at the initial stages of development. Using computer-generated models, Bering naval architects and designers are able to predict the noise and vibration impacts of design and machinery in the yacht and create spaces and arrangements that ensure seafarer safety and comfort at the early design stages. Precise design and architectural solutions as well as using the best available equipment and machinery ensure the excellent noise and vibration prevention results for each of the yachts made by Bering.
Among the tools we use is Rockwool noise and vibration insulation, which is installed in between the floors and walls of different spaces. Sound insulation boards of different thickness are also applied depending on the needs and amounts of noise and vibration for each particular space. Building charter-class boats requires the application of thicker layers for maximum protection. Along with the Rockwool slabs, Bering uses other heavy layer materials and acoustic voids that prevent noise and vibration spreading. Acoustically rated Thermaflex products are also used for exceptional sound and vibration control, especially for protection in heating and cooling systems.
Bering Yachts has employed an official analytics company to provide noise testing of one of its boats, a 2021-built 23,99-meter yacht Veronika, which is a standard procedure for newly built vessels at Bering. With its home in Australia, this boat has an impressive displacement of 165 tons and features a speed range between 8 and 11 knots. Testing took place in May 2021 and yielded extremely positive results.
The measurements were taken using the Bedrock SM90 equipment with the noise level measurement points located throughout the boat and measures taken in accordance with the ISO 16283-1. Noise levels were taken at anchor position and at maximum speed (@1700 RPM – 11.5 Knots). Below is the table comparing noise level recommendations from the American Bureau of Shipping, world-leading classification organizations and the results of Veronika testing.
Maximum noise levels for superyachts both for harbored and sailing conditions in comparison to B77 Veronika noise testing. Values in dB (A).
|Spaces||ABS Comfort (Y)||Bureau Veritas||Germanischer Lloyd (Cruise Ship)||Lloyd’s Register||RINA||B70 (AC level-2)|
|Harbour Sailing||Harbour Sailing||Harbour Sailing||Harbour Sailing||Harbour Sailing||Harbour Sailing|
As a result, almost all at harbor and at sailing conditions measurements of the B77 either exceed the recommended thresholds or stay within the limits for compliance measurements (within 3 dB(A) of the criteria for noise). (ABS 2016) This allows us to speak about our under-24-meter yacht as comparable to the superyacht in relation to noise safety.
Similar results were achieved during the vibration testing. VibroMatrix InnoBeamer device and RION VA-12 portable analyzer were used to test the whole body and the inner vibration of the ship. The measurements were taken at still and at maximum speed (@1,700 rpm – 11.5 knots). The results presented in the table below, with Veronika’s vibration levels significantly lower than those set for superyachts, confirm Bering’s commitment to vibration protection.
Maximum allowable levels for vibration for superyachts in comparison to B77 Veronika vibration testing at maximum speed.
|Location||BV||Lloyds Reg||RINA||ABS Comfort (Y)||Bering 77 Veronika|
|Cabin and lounge||1.0-3.0||1.8-2.5||1.0-3.0||1.5-2.25||0.06-1.02|
Bering is dedicated to making seafarer’s life onboard as pleasant and secure as possible, and the testing confirms this. Most values of noise and vibration onboard of Bering 77 are around or better than recommended ones from the regulations related to the superyachts. Fancy design, speed, luxurious amenities are not everything. Do not forget to include noise and vibration testing in the checklist while looking at other boats you plan to buy or charter.
1. American Bureau of Shipping (ABS). Guide for Crew Habitability on Ships. 2016.
2. American Bureau of Shipping (ABS). Noise and Vibration Control for Inhabited Spaces. 2017.
3. American Bureau of Shipping (ABS). Comfort on Yachts. 2019.
4. American Bureau of Shipping (ABS). Ship Vibration. 2021.
5. Boote D., Blake J., Flay R., Suthreland L. ISSC Committee V. 8: Yacht Design // 18th International Ship and Offshore Structures Congress. Vol. 2. 2012. DOI: 10.13140/RG.2.1.3985.7366.
6. Bureau Veritas. Rules For the Classification of Steel Ships. Part F. Additional Class Notations. NR467. 2022.
7. Dev A., Chla Y., Tam I. Maritime Sustainability and Maritime Labour Convention – Reducing Vibration and Noise Levels on Board Ships for Health and Safety of Seafarers // Conference Paper. 2017.
8. Pais, T., Boote D., Dellepiane, S. Vibrations of Superyacht Structures: Comfort Rules and Predictive Calculations // Proceedings of the 4th International Conference on Marine Structures MARSTRUCT 2013. EID: 2-s2.0-84874466721.
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