Brüel & Kjær’s real-time noise monitoring subscription service, NoiseSentinel, is set to ensure the compliance of the Crossrail construction works.

Crossrail is a large infrastructure project that will create a new rail link across London from west to east. Since significant amounts of the necessary construction work will take place in highly built-up areas, with night works required in some cases, noise compliance is a critical consideration for the building contractors.

The building contractors operating at the Liverpool Street site, BAM Nuttall Kier Joint Venture (BNK JV), turned to acoustic consultants Anderson Acoustics for a real-time noise management solution – in order to fulfil the Crossrail project’s noise pollution obligations, and prevent operations being delayed.

Andy Knowles, director of acoustic services at Anderson Acoustics, said: "Given the scale of this construction and the constraints, a key requirement was high reliability of the noise monitoring system. Experiencing failures that could require construction work to be stopped is not an option. The capability to present the data in the right place at the right time was critical."

The NoiseSentinel system hardware is entirely owned and operated by Brüel & Kjær, allowing the building contractors BNK JV to avoid capital outlay on equipment, and to focus on their core business. This was also a key consideration for the consultancy Anderson Acoustics, who were attracted by the ability to completely outsource the monitoring part of their services, while being supplied with the data needed to provide consultancy services.

Mr Knowles said: "Brüel & Kjær offers a highly professional and complete package that enabled our client to meet their obligations whilst not having to purchase and operate hardware. This means they are able to focus on effective management of noise from their works whilst freeing our resources to provide them with expert support on this complex issue."

A web-based interface monitors and warns management staff of noise increases, with a trigger alerting them of any small noise increase above pre-determined threshold, warning that a noise limit may be close to being breached and mitigating action should be taken. Noise increases significantly above a pre-determined threshold will trigger an alert, as a noise limit may have been breached. A sound recording is automatically made whenever an alert is issued, and this is available to the site operators within seconds, so they can investigate the source of the noise and determine if it was construction noise or not.

At the Liverpool Street enabling works site, there are three noise-sensitive locations nearby where real-time monitoring is required as a condition of the Section 61 planning consent issued by the City of London Corporation. BNK JV also decided to install a fourth noise monitor on the construction site itself, so that events could be related back to this site with greater certainty.

Dan Saunders, European sales driver for Brüel & Kjær, said: "We are very pleased that our service is able to assist in the Crossrail construction project, and see it as a logical solution for large projects of this type – completely freeing the project drivers to focus on what they do best."