- make the building safe to work on and enter
- provide protection for the works as they progress
- protect and, where possible, retrieve existing heritage fabric from what is a Category 1 Historic Place.
Stabilisation is being undertaken in two parts.
1. Global stabilisation
This stabilises the major external steel frames and associated elements (connections, foundations, etc) that provide the major load paths of support in key locations around the building:
- to reduce the risk of the whole Cathedral, or significant areas collapsing
- as a prerequisite for construction access to the interior of the cathedral
- to provide lines of support for any further temporary works that may be required during the strengthening and reinstatement.
2. Local stabilisation
In general terms, this stabilises the secondary support systems (which will be installed progressively between the global stabilisation elements) to protect the building’s fabric.
Local stabilisation includes specifically designed lateral support elements or an amalgamation with other construction activities, such as access platforms or wall support systems, to enable wall strengthening to be carried out.
Global and local stabilisation will:
Include the deconstruction of some badly damaged sections of masonry to effectively manage collapse hazards and allow access to other areas that will eventually be reinstated.
More recent additions to the Cathedral (particularly the vestries and Visitors’ Centre) have been demolished to give safer, faster access to stabilise the damaged original sections of the cathedral.
The final step in the stabilisation phase involves accessing the interior of the building for salvage and investigation works; retrieving heritage items, remaining stained-glass windows and organ, followed by decontamination and temporary weather protection.
Christ Church Cathedral Reinstatement Limited (CCRL) appointed Holmes Consulting LP as structural engineers to lead the stabilisation design and Naylor Love Canterbury Ltd as consultant contractor. The three entities worked to agree and adopt a reasonable and achievable approach to manage the health and safety of workers as required by the Health and Safety at Work Act. We are focused on work planning and execution to ensure everyone working on the project goes home safely.
As we work through stabilisation, we make more discoveries which validate the assumptions we’ve made and incrementally increase our knowledge of the building (including how it was built).
Stabilisation is not an easy or straightforward process but through collaboration between CCRL, Holmes Consulting, Fulton Ross Architects Heritage Professionals and Naylor Love, we have assembled the capability to work out not only what needs to be done, but how it can be done safely and efficiently.
Images below show the areas of stabilisation.