Blackburn cathedral undergoes 360° Laser Scan

Blackburn Cathedral, Church of St Mary's, is the city's oldest and only Anglican cathedral dating back to the 17th Century. The church as seen many developments over time, and with further works planned, Met Surveys were called upon to survey the Cathedral using the latest 360° laser scanning technology.

Standing in the centre of Blackburn from as early as the seventeenth century, the Cathedral has undergone many developments. Originally a stone built church at the time of the Norman conquest the church has been rebuilt several times with the latest building being consecrated in 1826, and is now one of the earliest examples of nineteenth century gothic revival.

Originally Blackburn's Parish Church, the Cathedral was awarded its status in 1938 when monies were raised to build an extension to the existing building and a crypt. Work was completed in 1977 and the remainder of the building was consecrated, providing Blackburn with Lancashire's only Anglican Cathedral.
Click here for animated view.
The Cathedral has become a focal point for the city today and continues to develop and expand as necessary to meet the needs of it's parishioners.

The Cathedral is not only used as a place of traditional worship, the church also holds events and concerts etc. With further structural development works planned at the Cathedral, Met Surveys were approached to carry out a High Definition scan of the internal and external features of the Cathedral as well as its surroundings.

Met Surveys Ltd, a leading land, building and geophysical surveying company were approached to carry out this detailed survey, and provide detailed 2/3D drawings to enable design works to commence as well as provide an archived record of the Cathedral's development and structure.

The Cathedral was surveyed using a HDS 3000, the latest in High Definition scanning technology from Leica. This revolutionary new piece of equipment has changed the way in which surveys can be conducted. Gone are the days in which a surveyor was only able to measure a single point at a time, 360° laser scanning allows for the measurement of up to 1800 points per second at a pre-defined density of as little as 1mm.
The survey was conducted both internally and externally to provide a complete view of the Cathedral. The Cathedral was scanned at an accuracy of +/- 6mm at intervals of 10mm per point. This accuracy increased as scans were overlapped and a three dimensional model of the Cathedral was produced for the purpose of generating elevation and sectional information.
The grounds of the Cathedral and local street scenes were also surveyed to provide a true picture of the Cathedral and its surroundings.

Traditional surveying methods were used to survey adjacent buildings due to the reduced level of detail required and time scales involved.

Within the grounds of the Cathedral stands a Statue of Queen Victoria, which also needed to be surveyed using the laser scanner. A 3D image was produced with a point cloud density of 3mm.

The survey took a total of 4 days to collect all internal and external scan information, which combined with the associative software allowed for 2/3D plans, models to be produced.

The Cathedral remained open whilst the survey was being carried out, which presented several challenges to the surveying team. Access to the inside of the Cathedral was limited and scans had to be gathered around ceremonies. Due to restrictions in place full access to the roof was not possible, hence the roof was only partially surveyed, however due to the extensive range and capabilities of the scanner the team were able to pick up all necessary information from ground level.