Freudenberg Sealing Technologies Merkel Develops Noise-Reduction Sealing System for Underwater Construction

   Freudenberg Sealing Technologies Merkel Develops Noise-Reduction Sealing
                      System for Underwater Construction

Innovative noise reduction provides protection for marine mammals

PR Newswire

PLYMOUTH, Mich., Aug. 15, 2013

PLYMOUTH, Mich., Aug. 15, 2013 /PRNewswire/ -- Freudenberg Sealing
Technologies Merkel (Freudenberg) had a goal: less noise pollution for harbor
porpoises affected in the installation of offshore wind turbine systems.
Through the development of a special sealing system, Freudenberg was able to
reduce the underwater noise generated during foundation work for offshore
facilities by 10 decibels.

When doing foundation work for offshore wind power stations, the noises that
result can pose substantial stress for marine mammals, such as harbor
porpoises, that have a very acute sense of hearing. For that reason, in 2006
the German Federal Office for the Environment commissioned a study on the
reduction of noise from underwater ramming work offshore. Hands-on testing was
also performed to examine various noise-reducing processes.

Five years later, the German Federal Agency for Nature Conservation followed
up with a study on the status of the developments. Its findings revealed that
the air-cushion process was the most effective and cost-efficient sound
proofing measure. In this process, columns that are to be driven are enclosed
in a hollow pipe. Inside the pipe, an air cushion is generated, resulting in a
significant reduction in noise emissions.

Based on these results, Freudenberg developed a special sealing system that
insulated the noise source in the water. The requirements for this sealing
system are highly sophisticated and include:

  oLarge diameter of approximately 2.5 meters,
  oAbility to perform at a depth of up to 40 meters and at a high pressure of
    up to 6 bar,
  oDeviation in the seal gap of up to +/- 25 millimeters.

Freudenberg's simulation and computation tools made it possible to produce an
initial prototype, and subsequently develop a sealing system with specially
shaped sealing elements, in a short amount of time. This sealing system
consists of three sealing rings that enclose the external hollow pipe on its
upper end against the column to be driven. This allows air to be compressed
into the middle space, displacing water. The multilayer configuration of the
seals allows for high pressures to gradually be decreased.

About Freudenberg Sealing Technologies

The technology specialist Freudenberg Sealing Technologies is a supplier,
development and service partner for customers from a variety of market
segments, such as the automotive industry, civil aviation, mechanical
engineering and shipbuilding, food processing and pharmaceuticals, or the
agricultural and construction machinery industry. On the basis of the
Simmerring® developed by Freudenberg in 1929, Freudenberg Sealing Technologies
now has a broad and continuously customer-oriented product portfolio of seals.
Based on detailed process knowledge, innovative development methods and
selected materials, the range includes both customized individual solutions as
well as complete seal packages.

Together with its partners NOK Corporation, Japan, Sigma Freudenberg NOK,
India, and NOK-Freudenberg Group China, Freudenberg Sealing Technologies forms
a global network which aims to supply its customers all over the world with
products of the same high quality.

In fiscal 2012, the largest business group of Freudenberg generated sales of
more than 1.68 billion euros and had a workforce of about 12,000 employees.
The company is part of the Freudenberg Group whose business areas Nonwovens,
Seals and Vibration Control Technology, Household Products and Specialties and
Others generated sales of more than 6.3 billion euros in 2012 with a workforce
of 37,453 in 57 countries.

SOURCE Freudenberg Sealing Technologies Merkel

Contact: Cheryl Eberwein, Director, Media Relations, Office: +1 734 354 7373,
E-Mail:, Lisa Gentile, Public Relations, Office: +1
734 354 5439, E-Mail:
Press spacebar to pause and continue. Press esc to stop.