Witley Court was once one of England's great country mansion houses. Today, as the result of a disastrous fire in 1937, it is an impressive ruin which is undergoing painstaking restoration by English Heritage.
It is not surprising therefore that when a bat colony was discovered prior to the start of a building project to provide educational facilities at the Visitor Centre, it was taken very seriously. The first step was to obtain advice from English Nature, and the conclusion was that ecologists needed to watch the bats and monitor their welfare. In due course Chubb Electronic Security was called in to provide the necessary technical advice .
Alan Capewell English Heritage Technical Manager for the West Midlands Region explains: “As contractors removed the timber wall cladding in order to commence work, a colony of bats was found in the wall which we were building on to. Having taken advice from English Nature and the ecologists, the conclusion was that once the bats had left their Winter hibernation, we could commence with the building work and create an environment that would encourage the bats to return to in the near future.”
The solution was to build special bat enclosures within the roof structure, with access through the roof tiles, and to install a surveillance system from Chubb. Once the building was complete, the ecologists would be required to monitor the building and the new bat boxes, to check whether the bats had returned. Traditionally, this would require ladders to gain access to the roof void and physically inspect each box – an awkward process.
A CCTV solution however, would minimise disturbance of the bats, and could also be incorporated into the education programme provided By English Heritage. Chubb Electronic Security was called in to provide a tailor-made infra-red CCTV system in order to be able to watch the bats in their natural habitat. As well as being of serious interest to the ecologists, the roof space is located above a newly built education room, which allows visitors to the site, and parties of school children, to watch live and pre-recorded footage of the bat population living above their heads.
Tony Skelton of Chubb Electronic Security was responsible for advising on, specifying and constructing the CCTV solution that would be best suited to this purpose: “The challenge with this project was that the bats need to live in a completely dark environment, and yet we needed some level of light in order for the cameras to function and relay visible imagery to the screen downstairs."
“Having consulted the ecologists on the requirements of the bats, we decided to develop a one-off custom-made infrared illumination system. We arranged for special lighting to be installed on rods in the bat boxes within the roof rafters, which would emit no heat and only very low levels of LED light signals, imperceptible to the human (or bat’s) eye."
“This then works in conjunction with several high-sensitivity black and white cameras which are very small (40mm by 25mm) in order to be as unobtrusive as possible. These premium, high performance cameras were fitted with very sensitive lenses which could work using the minimal levels of light, and at the same time leave the bats in the peaceful, pitch dark habitat that they need.”
The cameras produce low noise, high quality images and are connected to a four channel DVD recorder which will show any movement in the bat boxes live on the 20” flat screen TV in the education room below. The building was completed in June 2006 and the end result is a working bat enclosure which the ecologists can monitor without the inconvenience of directly accessing the space. lan continues; “We are really delighted with the interest that Chubb has shown in this rather unique project, and the work that they have done for us. The bats were clearly very comfortable in this building and we can only hope now that they will be as happy with their new enclosures.”
Chubb Electronic Security has worked on several bespoke projects for the English Heritage. Another recent success was the installation of radio equipment at Kenilworth Castle, which can transmit TV pictures via a microwave video link across the site.