July 2016 Blog: Clerk of Works
During June 2016 anyone visiting the Cathedral may have possibly noticed the presence of lots of technical-looking devices set up in the building and their operatives roaming the Cathedral and requesting furniture and items to be moved. Chris Sampson, Clerk of Works, gives us a quick explanation:
“We have commissioned two separate surveys to be undertaken, both requiring full uninterrupted access to the Cathedral floor:
A laser survey of the Cathedral will give us a full measured floor plan and elevations of the interior; the raw data from the survey produces a 3D-pointcloud representing all footprints (hits) of the laser scanner which is mapping all surfaces. From this 2D drawings can be produced and if required 3D building information modelling. Some of you will find it very bizarre to learn that we are still working from plans of the Cathedral drawn originally in the 18th century, 1797 to be exact. Although these where done extremely accurately and the Cathedral has not changed dramatically since then, a modern digital version will be much more accurate and essential for all our future planed works.
A ground-penetrating radar survey (GPR) will we hope tell us what is actually under the floor and buried in the ground in the Cathedral. GPR is a geophysical method that uses radar pulses to image the subsurface to a depth of approx. 2m, dependent on ground make up. As well as identifying existing pipe and cable runs it will hopefully show us voids beneath slabs and burial monuments. Again this information is essential for all our future planed works.”
Photo (showing the former Nave furniture): Peter Stephens