Restoration of the Old Grange Ruin and Brockhill Bridge
By Rob Firman, Director, Austin-Smith:Lord
Austin-Smith:Lord has been providing Conservation Architecture advice to the Ministry of Justice Estates Directorate project team through Mott MacDonald for the restoration of the Old Grange Ruin and Brockhill Bridge at Hewell Grange in Worcestershire since May 2017.
The two elements of the project have fascinating histories and presented exceptional challenges to the project team as we worked with the Contractor to complete the restoration works. Set within an 18th Century Capability Brown landscape that had been modified by Humphrey Repton early in the 19th Century, and both listed Grade II, their restorations required sensitivity and a lot of patience.
The Ruin had been unattended for over 25 years when the project to restore and conserve it commenced and it was at significant risk of collapse, extremely overgrown with invasive and damaging vegetation and inaccessible for detailed inspection to ascertain its true condition. The restoration project aimed to return the structure to a stable and self-supporting condition and leave the fabric of the remaining walls and features sufficiently repaired to minimise ongoing maintenance in the future.
The Bridge had partially subsided on one side as the water running over the adjacent weir had undermined one of the abutments and the twisted structure and deck required stabilisation and straightening. The restoration works aimed to realign and stabilise the bridge structure.
The original house at Hewell Grange dates from around 1705 and was adapted and modified several times in the late 18th and early 19th centuries until it reached its final form in 1815. Capability Brown carried out works to the grounds in 1760 and 1761 and in 1811 Humphrey Repton was appointed to re-design the grounds. Hewell Grange can therefore boast of having England’s two greatest landscape designers create its grounds and gardens and this undoubtedly contributes to them being listed Grade II*.
The ruin we see today was created by a fire that largely destroyed the house in 1889. There is a suggestion that the fire was caused by fireworks being set off to celebrate the presence of the Shah of Persia at the Estate but the reality is probably less exotic. A new house was already under construction when the original one burned and it was decided to leave the ruin as a preserved object in the landscape.
In 1945, Hewell Grange together with 5,500 acres of land was placed on the market to settle death duties and in 1946 it was announced that the mansion and grounds was to become an experimental Borstal. Stewardship of the property passed to the Ministry of Justice from then and remains part of the MoJ property estate to date. In the early 1990s the condition of the ruin was causing concern and a scaffold frame was built to support it. The ruin and immediate perimeter was secured behind a fence to prevent access and prevent the risk of accidents caused by falling stonework and the ruin remained in that condition for nearly 30 years.
In 2017 Austin-Smith:Lord joined a team led by Mott MacDonald to assist in proposing a methodology for the stabilisation and restoration of the ruin. The site was completely overgrown with self-sown trees and ivy covered every visible surface of the structure. It was a veritable self-supporting eco-system! In early 2018 Vinci Construction was appointed as main contractor to deliver the stabilisation and restoration works.
Over the last 4 ½ years the process of restoration has been impacted by birds nesting on and bats roosting in the stonework and by the Covid-19 pandemic. In the spring of 2020 one of the free-standing sections of wall on the southern elevation collapsed and consequently all parts of the ruin in that area had to be taken down to ensure safety of the workforce and carefully rebuilt later. Throughout the construction period the restoration work has been painstakingly executed by a team of specialist stonemasons and bricklayers and Austin-Smith:Lord has visited the site on a monthly basis to monitor progress and quality in our role of Technical Advisor for Conservation on behalf of the MOJ client.
By the summer of 2022, works have been completed on the majority of the ruin structure with rebuilding of the collapsed section at the rear ongoing and repairs to the portico structure at the front about to commence. There will be many more challenges to face to ensure that the whole ruin will be standing for future generations to enjoy but the wait will be worth it.
As part of the redesign works he was commissioned to carry out in 1815, Humphrey Repton proposed construction of 2 new bridges, one of which is now known as Brockhill Bridge. It was constructed around 1820 to his design using cast-iron from Horseley Iron Works in Tipton. It appears to have been installed as a feature in the landscape to cross the lake at a narrow point which allowed views down the lake to a boathouse and Hewell Grange house beyond. Primarily used as a footbridge it has never needed to be upgraded and is therefore an unaltered example of its type, closely reflecting the design of cast-iron bridges dating from the end of the 18th and early 19th century, of which only a few survive. It is listed Grade II.
As part of the installation of the bridge a cascade was constructed just north to provide a further landscape feature, as well as the sound of rushing water while viewing the house and grounds.
The bridge had not been maintained for a considerable period of time and had noticeably fallen into disrepair with the area around it becoming heavily overgrown. The Austin-Smith:Lord and Mott MacDonald team working on the Ruin project was invited to make recommendations for the stabilisation of the bridge in October 2020 such that the works could be executed in parallel with the works at the Ruin.
A report on the bridge in November 2020 noted ‘a combination of water erosion from overspill of Brockhill Weir and invasive tree root action at the west abutment have resulted in a destabilised arch. Relative displacement at the west abutment in three-axes have allowed the northern arch to spring. Consequently, the bridge deck now lists towards the failed northern arch, the cast “crown-tie” at the crown of the arch has failed, along with the north parapet railings where the horizontal chords of the parapet have buckled in compression along with individual vertical balusters shearing in tension’.
A detailed program of works comprising 20 phases was devised by specialist sub-contractor Freysinnet to stabilise the bridge, including dismantling and reconstructing the western stone abutment, supporting, removing defective elements for replacement, jacking the failed northern side to the horizontal, installing a recast crown linkage, and removing supports, and some minor reinforcement.
The works commenced on site in spring 2021 and were completed in summer 2022. The bridge is now levelled and square and has a new resin-bonded gravel deck to enable pedestrian traffic to use it once again. The works provide for the long-term preservation of the bridge, ensuring its heritage significance is retained, as well as its contribution to the heritage significance of the wider Hewell Grange Park and Garden.
The combination of the restoration and stabilisation of these two significant heritage assets in an outstanding heritage landscape has provided the Austin-Smith:Lord Conservation team with some of its most challenging and rewarding experiences and following our previous work with heritage assets in special landscapes at locations as diverse as Lews and Portencross Castles in Scotland, Caerphilly Castle in South Wales and The Great Pagoda at Kew Gardens reinforces our expertise for such unusual projects.
Our next project of this type is at the Grade I listed Transporter Bridge in Newport, South Wales, due to commence restoration work later in 2022 and complete in 2024. It will ensure we continue to develop our skills and expand our portfolio of conserving unique heritage asset restorations in special locations.