SubSea Quieter

SubSea Quieter Brochure 2024

THE SUBSEA QUIETER

The SubSea Quieter membrane is a technical fabric to which a coating has been applied to make it waterproof and resistant to the marine environment: waterproofing, salinity, corrosion.

Each SubSea Quieter panel is filled with air that can emptied or filled to manage coastal works activity phases, tidal range, currents and storms. The SubSea Quieter production method and operating principle have been protected by two patents. 

TWO TYPES OF SUBSEA QUIETER

TWO TYPES OF SUBSEA QUIETER

- Pile Driving
The SSQ Pile Driving for coastal works is used to abate underwater noise from pile driving operations in coastal conditions. The system can confine piles ranging from 1m to 2.5m in diameter.

It is particularly adapted when the maritime conditions are difficult: important tidal range, current, swell, depth.

Characteristics:
A complex multi-layer membrane
An automatic system to manage air pressure inside each membrane panel
Deployment and inflation time:  <15 minutes 
Mass of the SSQ: 20 to 40 tons 

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 - Blue Shield
The SubSea Quieter Blue Shield system takes the form of a wall made up of 2 layers of membrane that are inflated with air and that act as a noise abatement system and a barrier against turbidity.

Each row of panels is managed independently to manage the quantity of air to be inserted according to the depth level and to be able to inflate/deflate automatically certain rows according to the tidal range or to let a ship pass through the containment area.

Characteristics:
A complex multi-layer membrane
An automatic system to manage air pressure inside each membrane panel
Inflation time for 300m: <1h30
An anchoring system

ADVANTAGES

ADVANTAGES

A simple and modular design
A design that adapts to the types of work and characteristics of the site:

  • A modular design to adapt to multiple configurations of type of works and maritime conditions
  • An installation that does not require heavy means, nor extra cranes or vessels

A technical innovation
The SubSea Quieter membrane is the “double glazing principle” adapted to maritime constraints:

  • An underwater noise reduction between 10 and 45 dB depending on frequencies. 
  • A solution with a double capacity: noise mitigation system and barrier against turbidity
  • A system designed and tested to resist maritime constraints: swell, currents, pressure, corrosion

TECHNOLOGY READINESS LEVEL

  • TRL at the end of 2017 : 5
  • Technology developed by Naval Group’s underwater acoustic experts
  • Technology protected by 2 patents
  • First prototype tested in real conditions in Norway with NTNU Trondheim University in summer 2017
  • TRL at the end of 2024 : 7/8
  • Noise attenuation measured by the NPL UK laboratory and numerical modeling ¼ of the basin-scale test in 2020.
  • Tests in St Nazaire in maritime conditions in 2024.

ACOUSTIC PERFORMANCES

1st Gen : Measured by NTNU in Norway (2017)

Results:
15dB until 2kHz,
Up to 35dB above 2kHz

2nd Gen : Measured by NPL in England (2019)

Results:
25dB at 1000Hz
30 to 60dB over 3kHz
(Better results and fully industrialized)

Extrapolation under 1kHz:
12dB at 100Hz
17dB at 200Hz

Measured by Quiet Oceans (2024)

Results:
60 Hz: 12 – 14 dB
100 Hz: 12 – 15 dB
200 Hz: 10 – 14 dB
500 Hz: 18 – 21 dB

3 types of sources were used:
Pulse Low Frequencies (50 - 1500 Hz)
Pulse High Frequencies (300 Hz to 20 kHz)
Air Gun system (impulsive and low frequencies sounds)

Conclusion:
The results are better than those expected by numerical modelings.

SSQ outperforms existing systems at low frequencies.

Confined Bubbling Belt brings an additional reduction of between 3 to 10 dB, with almost no extra cost.

The bubble will not be affected by current and waves.

Testings at St Viaud 2023 & St Nazaire 2024

SubSea Quieter Brochure 2024