Denton Wharf Blast Bay

A case study of design, simplicity and sustainability.

From time to time the simplest problems are often the most satisfying to resolve. We can think of no better example of this in when asked to reduce the noise from the Port of London Authority’s buoy blasting bay in Denton Wharf, Gravesend.

Amongst many other repair and maintenance, planning and logistics activities, it is the role of the Port of London Authority (PoLA) to remove buoys from the River Thames, and clean barnacles, rust, corrosion and detritus from each buoy before they go back out into the river, all occurring on the dockside.

This cleaning uses an industrial manual water pressure washer, rather more powerful than your average car jet wash, and producing high noise levels as the high-pressured water hits the surface of the buoy.

The PoLA needed to control this noise to allow the rest of the dock to be used effectively without giving rise to rise extraneous noise exposure.

With Sharps Redmore measuring the activity within and outside a simple temporary tarpaulin safety screen, the PoLA wanted to use the materials at hand to build something more effective. In this case, re-cycling large wooden railway sleepers.

A screen constructed mainly from timber sleepers was wrapped around the blast bay on all sides to act as an acoustic barrier to the rest of the wharf. Large timber doors were constructed on the front of barrier and the mobile pressure washing pump enclosure, which itself generated noise.

Small windows allowed viewing of the activities safety for other staff on the wharf, and the materials used were weather treated during the construction process to ensure that the design would last for many years to come.

The concept of simplicity was carried throughout the assessment; all calculation were undertaken by hand, no modelling software was used, and the predicted noise reduction, when re-measured, achieved within around 1-2 dB of predictions round the outside of the barrier.

The staff at Denton Wharf did a fantastic job of bringing our design to life, constructing the screen to a high level of detail, whilst taking on board the principles of good acoustic design, which ensured the achievement of the predicted noise reduction desired.

The result is now a wharf more effective, more productive, and noticeably quieter!

We were delighted to be a key part of this project which showed, creativity, sustainability and the basic laws of noise control working well.