A recent noise and vibration test in the North Sea was also a test of sea legs.
AJA consultants Adrian James and George Moore stepped aboard one of the boats in Lowestoft which is used to access offshore wind turbines.
Crew vessels
These crew vessels are constantly taking engineers and maintenance workers to and from the North Sea wind farms.
Passenger comfort is important as the seas can be rough. Adrian and George took measurements to ensure the relevant standards were met. There are classifications for acceptable levels of noise and vibration, set out by DNV – the world’s leading classification society and advisor for the maritime industry.
Vibration testing
Vibration on the cabin decks and the bridge of the ship were measured using a tri-axial accelerometer, in this case a Rion VM-56. The assessment is made in terms of RMS velocity over a one-minute measurement period. The vessel must be travelling on at least 80% of maximum power in sea state where waves can be up to 1.25m high.
Once back in the office, the readings form the basis of a report, so that the client can use them as part of their comfort standards of compliance.
Construction vibration
Thankfully, we don’t always need such a strong stomach to test noise and vibration. Much of our work takes place on dry land, such as the measurement of construction noise and vibration.
We are experienced in assessing the impact of noise and vibration on nearby residents. We provide this service regularly for construction projects in residential areas.
Standards
Construction noise and vibration limits are set out in British Standards document BS 5228:2009. Adrian James Acoustics is increasingly receiving requests about complying with this standard. We are also happy to advise on the level of vibration required to effect material damage on buildings.
If you need to discuss noise and vibration issues, please do call us on 01603 721511. Whether on land or at sea, we are here to help.