Marine engines frequently produce noise levels as high as 110 decibels on the A-weighted scale (dB(A)), comparable to the loudness of a rock concert. Primarily, that noise concentrates in the low to mid-frequency, ranging from 125 Hertz (Hz) to 2,000 Hz, which includes the frequency range of many human speech sounds and underwater noises important for marine life.

In addition, there is low-frequency structure vibration-related noise. This type of noise, which is caused by the engine and machinery vibrations resonating through the ship’s structure, further complicates how marine soundproofing can be achieved. Reducing noise in marine environments requires a multifaceted engineering approach. This approach must account for both the air-borne noise generated by the engines and the structure-borne noise that leads to vibrations.

Applying our unique 4-Fold Approach® system, Megasorber engineers have successfully developed a range of marine soundproofing products to help reduce:

  • engine room noise
  • vibration noise from the hull & structures
  • wave slapping noise.

Engine Room Noise Reduction

1. Lightweight option:

NRC  up to 1.0

Megasorber FM50 (or FM25) to line the engine room or engine enclosure;
FM50:  NRC 1.0;
FM25:  NRC 0.82

Megasorber FM50 and Megasorber FM25 are inherently fire-resistant, exceptionally lightweight and highly effective. They have a non-combustible Soundmesh G8 facing, are splash-resistant to fluid, and are tough and durable.

The key marine soundproofing features of the Megasorber FM acoustic foam panels are demonstrated through the schematic drawings below:

Superior acoustic performance: Megasorber FM25 and FM50 are highly effective in absorbing engine noise. The graph below highlights the acoustic performance over the various frequencies.

The FM50 and FM25 provide excellent marine soundproofing absorption over engine noise frequencies. After installing Megasorber FM50, the typical noise reduction is up to 10 dB(A).

Learn more about how Soundmesh G8 boosts the acoustic performance of 25mm thick acoustic foam up to 54.5%.

2. Super-quiet option

Megasorber C50 and CM28

Megasorber C50 and Megasorber CM28 are marine soundproofing absorber-barrier composites. They are designed to effectively absorb and block the air-borne noise, specifically at a frequency range of the marine engine noise.

Megasorber C50 and Megasorber CM28 have a non-combustible Soundmesh G8 facing, are splash-resistant to fluid, and are tough and durable, as shown in the schematic drawings below:

Megasorber C50:  NRC 0.85;  Rw (STC) 28

Megasorber CM28:  NRC 0.80;  Rw (STC) 24

For more details on how Megasorber composites have been engineered to provide maximum soundproofing effect, please follow this link: Soundproofing Composites.

IMO Compliant Requirements

1. Economic option

Megasorber P50

Megasorber P50 is specifically engineered to absorb noise from marine engines, achieving its highest sound absorption efficiency within the range of 250Hz to 2,000Hz. It stands out as one of the few sound-absorbing materials that comply with the International Maritime Organization (IMO) standards, ensuring its suitability for use in marine environments.

Sound Absorption of Megasorber P Series Products

(Tested to AS ISO 354-2006 Acoustics: Measurement of sound absorption in a reverberation room)

2. Super-quiet option

Megasorber P50 + Megasorber D14

Megasorber D14 is engineered specifically to effectively mitigate low-frequency noise that is transmitted through the structure of a vessel, while Megasorber P50 is tailored to efficiently absorb noise that travels through the air, particularly noise emanating from marine engines. The Megasorber P series and the Megasorber D14 products both adhere to the IMO standards, ensuring they meet global regulatory requirements for marine noise reduction.

3. Reduction of a wave slapping noise and vibration noise

  • Best option: Megasorber DT2 or Megasorber D14
    Megasorber DT2 is tailored for use with thicker panels, accommodating aluminium panels up to 12mm in thickness, and steel panels up to 6mm in thickness.
    Megasorber D14 is more suitable for thinner panels, working well with aluminium panels up to 4mm thick and steel panels up to 3mm thick.
    Both options come with a self-adhesive backing for straightforward installation.
  • Economic option: Megasorber DIS8 (or DIS8WH-DS)
    Megasorber DIS8 comes with a double-sided self-adhesive feature, making it highly effective for damping vibrations in thick panels, especially those with intricate contours or shapes. Specifically designed to integrate seamlessly with the wet lamination process for FRP structures, Megasorber DIS8WH-DS is a versatile and cost-effective choice for noise and vibration reduction.
    For optimal performance, it is recommended to use the Megasorber DIS8 in conjunction with a top plate made from materials like steel, aluminium, or Glass-fibre Reinforced Plastic (FRP).

To learn more about how the damping materials act as marine soundproofing to reduce the impact noise of metal plates, follow this link:  Soundproofing Damping.

Demonstration of enclosure noise reduction

In this video, two identical metal boxes are constructed.  The red box has no acoustic treatment, while the green box has all the interior surfaces lined with Megasorber FM25, plus a door seal. It is a comparison test for demonstration only.

 

Sound absorption video for enclosure noise reduction

Sound recording before and after the installation of Megasorber sound-absorbing panels in a metal enclosure

Demonstration of fire resistance

Megasorber FM is designed with inherent fire resistance, achieving the highest level of compliance with Australia’s Building Code (BCA) Group 1 fire rating. This rating is based on the standards outlined in AS 5637.1-2015 and also meets the ISO 5660 Group 1 fire classification criteria.

When exposed to fire, Megasorber FM demonstrates exceptional safety features by not igniting, melting, dripping, or allowing the flame to spread. This is demonstrated in the video shown below.

 

Acoustic panels are inherently fire-resistant

No ignition, melting, dripping or spread of flame when exposed to fire

 

 

Marine engine room soundproofing

Megasorber’s FM acoustic foam is inherently fire-resistant and perfectly suits the harsh environments of marine engine room soundproofing.

Megasorber CM28 and Megasorber C50 are the absorber-barrier marine soundproofing composites for superior sound insulation.

View our FM range of absorption products

Essential marine soundproofing solutions

Marine soundproofing plays a critical role in enhancing the comfort and safety of maritime environments, addressing the challenge of reducing engine noise, vibration, and other operational sounds that can permeate through a vessel’s structure.

With Megasorber’s advanced materials and technologies, such as acoustic foams and barrier composites, employed to absorb sound and prevent its transmission, vessels can effectively create a quieter atmosphere for both crew and passengers.