Aerial inspection of our greatest buildings

Published: Friday, August 19, 2016

 

In July the National Churches Trust received £90,100 from the Heritage Lottery Fund (HLF) for the Yorkshire Maintenance Project. This will help keep churches and chapels in Yorkshire in good condition and prevent the need for expensive repairs.

Part of the project is to conduct drone surveys of churches to provide information for maintenance and repairs. The drone surveys are being carried out by Museum of London Archaeology (MOLA), an experienced and innovative archaeology and heritage organisation.

Dr Peter Rauxloh, Director of Technology Solutions at MOLA, explains the process: 

MOLA’s aerial survey team focussed their attention on the airborne inspection of the English Parish Church. Working in association with the National Churches Trust, with support from the Heritage Lottery Fund, we looked at nine churches in the Sheffield Dioceses over the course of a three week window. The purpose of the work is to determine how drone technology can help the early detection and on-going monitoring of these precious buildings, by providing view points, a level of details and derived metrically accurate perspectives,  unattainable form the ground. 

Every five years, each church in England is inspected both internally and externally. These inspections are carried out by a qualified architect, and the upper parts of the building are studied from the tower, if the church has one and it is accessible, or from the ground using a pair of binoculars. There are a number of problems with this approach, namely the inability both to see certain parts of the building from these two vantage points, and to see them in enough detail to help identify the existence, nature and scale of remedial action that may be required.

Holy Trinity Wentworth

We started at Holy Trinity, Wentworth, a beautiful Victorian church described by Sir Nicolaus Pevsner as a ‘very fine, sensitive and scholarly piece of Gothic revival’. With its 200 foot high spire and space enough for 500 people, this was an interesting choice for our initial survey, being by some margin the largest building we are to inspect. Built by the 6th Earl Fitzwilliam, it towered (or more accurately towered and spired) over the old Holy Trinity church in the village, yet the worthy parishioners stuck to their habit, and were not keen to move across to the new edifice. Being unimpressed by this entrenched reticence, the Earl provided some gentle encouragement by the simple expedient of removing the old church’s roof; an act remarkable for its decisiveness as much as its audacity.

The project will go on to inspect four other churches in the Doncaster area, and then another four in and around Sheffield.  As a number of interested on-lookers and enthusiastic incumbents observed, the drone does sound like a swarm of angry bees, which was both prescient and opportune for the Sheffield work. The drone has to date identified three infestations of its Apoidean relatives with two of these apparently being habitual gatherings of these docile creatures, at the same time and place each year. One wonders how long such instinctive communion has occurred in the walls and crevices of our places of worship.

A public event

While it is almost inaudible at operational heights when mapping the roof scape, the drone is certainly noticeable when shooting video or particular points of concern on the building. This gives rise to interesting pastoral opportunities. The Reverend Eleanor Robertshaw oversees the wonderful squat-towered church of St. Laurence Priory Snaith, and for the inspection was recruited - along with stalwart church wardens - as an additional observer posted on the pavement opposite. A steady stream of interested onlookers passed through her care, providing opportunity for discussion and  interaction. Perhaps also, it was a chance to appreciate for a moment, the fixedness, longevity and centrality of these ancient structures and the connectivity they provide between communities across the centuries.  

The core output from the project will be a report in which the products derived from the flying will be studied as to the benefit they provide to the inspection and monitoring process.  This assessment will be carried out in association with architects, the NCT, diocesan representatives and incumbents. Perhaps one of the most beneficial uses will be directed shots of known areas of building weakness, with the flight being conducted in association with those that know the building best.

To find out more about MOLA and its building inspection services:

http://www.mola.org.uk/services/historic-building-recording

http://www.mola.org.uk/services/aerial-survey

http://www.mola.org.uk/services/geomatics