Lion Bridge, Alnwick, Northumberland
Lion Bridge is a Grade I Listed Structure and Schedule Ancient Monument in Alnwick, Northumberland. Built in 1775, it is the most famous bridge on the River Aln and features four arches and a lead cast Percy Lion.
We were contracted by Northumberland County Council to conduct careful conservation repair and consolidation works, including removing and repairing friable areas of previous coatings, re-pointing open joints and supplying and fixing geologically matching stone to specific areas of the bridge.
THE PROJECT INVOLVED EXTENSIVE COORDINATION WITH THE CLIENT, NORTHUMBERLAND COUNTY COUNCIL AND HISTORIC ENGLAND TO PROMOTE THE PRESERVATION AND CONSERVATION OF AS MUCH HISTORIC AND ORIGINAL MATERIAL AS POSSIBLE.
The program of work
The project involved extensive coordination with both the client, Northumberland County Council and Historic England to ensure the most effective and systematic working that would promote the preservation of as much of the historic and original material as possible. The program of work was as follows:
- Hammer test, remove friable areas of previous coatings and repair as required
- Re-point in lime-based mortar to the contract specification all open joints identified
- Supply, mason and fix geologically matching stone to areas identified and detailed in the Scheduled Ancient Monument Consent including stockade chevron stones, arched voussoir stones, merlons and embrasure stones to the upper parapet
The equipment used
After conducting an assessment of the site and its wider constraints and identifying the need to avoid any physical fixings into the Scheduled Ancient Monument, a combination of methods was employed. The equipment required included:
- An independent scaffolding to the east wing/abutment walls on both upstream and downstream elevations
- Mobile tower scaffolding to access the land barrel sections
- A 38m truck-mounted Bronto for general access
- Edge protection for re-pointing the parapet works, facework and abutment walls
- An MBI150 Underbridge Unit to access the barrel intrados areas above the water and any lower sections of the facework