First harbor dredging noise study for Tiamat dredger

A recent study conducted into agitation dredging noise in harbors, confirmed that Haven Dredging’s innovative Tiamat Hydrodynamic dredger is safe for marine mammals and fish.

Tiamat, launched last year by Haven Dredging, is an innovative hydrodynamic dredging solution to create a more adaptable and environmentally friendly solution.

Following a comprehensive survey with the environmental hydraulics consultancy, HR Wallingford, a leading specialist in modelling and measurement of marine noise, was also found to be significantly quieter than a small Trailing Suction Hopper Dredger (TSHD).

When being pulled by a small workboat, the noise level of Tiamat was around 170 decibels (dB), while a 3,500 cubic meter TSHD – was around 185 dB.

It was noted in the study, Measurements of Tiamat and TSHD Noise Disturbance: “The measured sound pressure levels emitted from Tiamat (and the Bella workboat) are below the levels associated with direct injury to marine mammals.” It also states that fish are also unlikely to be hurt.

The US-based, National Oceanic and Atmospheric Administration suggests approximate sound pressure level (SPL) thresholds are 180 dB for whales and 190 dB for seals.

“The results of this study are testament to the years of research and field testing that has been put in to creating Tiamat,” commented Jake Storey, Executive Director of Haven Dredging. “Tiamat aims to not only build awareness around environmental issues from traditional dredging methods in the port and dredging community, but also to provide businesses with the opportunity to choose a more responsible, sustainable and economical method of dredging.”

As well as being quieter, Tiamat provides a cleaner and greener method of maintenance dredging, that is easy to deploy, adaptable and at a lower cost.

Dr. Thomas Benson from HR Wallingford – who completed the noise study – added, “Measuring underwater dredger noise within a busy harbour environment presents considerable challenges because of all the other noise generating activities taking place, but the results of this study are clear in that the Tiamat makes a lot less noise compared to more traditional trailer dredgers. This adds to the other benefits of the Tiamat such as having a low-carbon footprint and being cheaper to run.”

The 43-page report compared SPLs of Tiamat and the 3,500 cubic meter TSHD. The tests were conducted at Harwich Harbour, in Essex, UK.