Specialist Conservation Works to a Grade II Listed Landmark on Darwen Moor
UK Restoration Services was appointed by Blackburn with Darwen Borough Council as Principal Contractor for the conservation and repair of Darwen Jubilee Tower, one of Lancashire’s most recognisable historic landmarks. Located at the summit of Darwen Hill, overlooking the town of Darwen and the wider West Pennine Moors, the Grade II Listed tower occupies a highly exposed and environmentally sensitive position within a Site of Special Scientific Interest.
The project required a carefully planned programme of masonry conservation, lime grouting, lime repointing, asphalt roof repairs, rainwater goods renewal, soffit repairs, metalwork refurbishment and associated specialist works. The repairs were undertaken to consolidate the historic fabric, improve weathering performance and extend the service life of the tower while retaining its architectural character and public significance.
Darwen Jubilee Tower, also known as Darwen Tower, was completed in 1898 to commemorate Queen Victoria’s Diamond Jubilee and to celebrate local people securing the right of access to Darwen Moor. The octagonal sandstone tower rises approximately 85 feet and remains a prominent destination for walkers, visitors and the local community, offering extensive views across Lancashire, North Yorkshire, Morecambe Bay, Cumbria, North Wales and beyond.
Principal Contractor for a Sensitive Heritage Site
As Principal Contractor, UK Restoration Services was responsible for managing the construction phase, coordinating specialist subcontractors, maintaining public safety, protecting the surrounding SSSI landscape and delivering the works in accordance with the conservation specification.
The site presented several constraints from the outset. Darwen Tower is remote, exposed to severe wind and rain, accessible by public rights of way and surrounded by sensitive moorland habitat. This required detailed planning for access, logistics, welfare, scaffold design, site security, ecological protection and weather-dependent working.
The construction phase was managed through a live Construction Phase Plan, regular site inspections, toolbox talks, environmental briefings and ongoing liaison with the client, contract administrator, ecologist, scaffold designer, conservation specialists and subcontractors. The project team included specialist input for scaffolding, ecology, lightning protection, asphalt roofing, handrail installation and conservation engineering.
Project Scope
The conservation and repair works included:
- Lime grouting and lime repointing to the tower masonry
- Deep tamping of open joints and voided masonry
- Raking out and repointing to internal and external masonry joints
- Masonry repairs, re-bedding of loose units and lintel repairs
- Dismantling and rebuilding of the upper section of the tower
- Grouting and rebuilding of wall heads
- Asphalt roof repairs and new lead outlet installation
- Renewal of rainwater goods in cast iron
- Soffit repairs to concrete landing areas
- Cleaning and treatment of exposed iron joists
- Installation of new steel framing, fixings and stainless-steel mesh underdrawings
- Refurbishment of the dome and lantern
- Replacement of lantern panes with Perspex
- Conservation cleaning of plaques and memorials
- Repairs and repainting to iron stairs and metalwork
- Replacement balustrading and handrail works
- Production and installation of new oak external door sets
- Reinstatement of the lightning protection system
Lime Grouting, Deep Tamping and Masonry Repointing
A significant element of the project involved the consolidation of the tower’s masonry using lime-based materials. Following raking out works, it became clear that many of the perp joints contained larger voids than originally anticipated. In some areas, loose masonry units were found and carefully re-bedded as part of the repointing process.
UK Restoration Services carried out sample panels and trials to establish the correct approach to lime grouting, deep tamping and pointing. The grout mix and pointing mortars were selected to suit the historic sandstone, the depth of voiding and the highly exposed moorland environment. The methodology was developed to ensure adequate carbonation at depth, good compaction, vapour permeability and compatibility with the existing fabric.
The deep tamping works were carried out using custom-made hods and ramming tools. Each scaffold lift and each face of the tower were labelled, with operatives allocated defined working areas. Joints were checked by the site-based contract manager and supervisor to confirm depth, compaction and consistency. This level of quality control was critical in ensuring that the new lime work was properly consolidated rather than simply finished at the surface.
During the colder months, the team introduced temperature monitoring across the scaffold and working areas. Temperature logs were maintained daily and used to inform working methods, protection measures and curing arrangements. Hessian protection and close monitoring helped safeguard the lime works during frost risk and adverse weather.
Masonry Cleaning and Conservation Detailing
The stonework was cleaned using low-impact methods appropriate to the condition of the masonry and the sensitivity of the site. Natural bristle and nylon brushes were used with controlled quantities of clean water to remove dust, debris, biological matter and surface contamination, while avoiding excessive run-off that could stain new lime pointing or affect the surrounding environment.
The project also included conservation cleaning of plaques and memorials, removal of lichen and moss growth, and repointing of open joints around these features. Where necessary, existing plaque elements were removed and handed over for specialist review, ensuring that decisions around repair and reinstatement were based on conservation-led assessment rather than unnecessary intervention.
Asphalt Roof Repairs and Rainwater Goods Renewal
The upper observation areas and roof coverings required targeted repair to improve weathering performance. Works included crack and blister repairs to asphalt using a poultice method, patch repairs around the doorway to the lantern, removal of redundant elements and installation of a new Code 7 lead outlet to the top deck asphalt.
Existing boxed-in and UPVC rainwater goods were removed and replaced with new above-ground 3-inch cast iron rainwater goods, sealed to gullies at the upper and lower observation decks. The cast iron pipes were painted as part of the works, reinstating a more appropriate and durable rainwater system for the historic structure.
Dome, Lantern, Staircase and Metalwork Repairs
The dome and lantern were carefully refurbished, including cleaning of glazing and frames, repainting of the frame and replacement of lantern panes with Perspex. This provided a more robust finish suited to the exposed location and improved the ease of future maintenance.
The iron staircase and associated metalwork were also addressed. Corrosion and old coatings were removed using controlled methods, with task-specific controls for lead paint removal, including air-fed full-face masks, disposable PPE, exclusion zones, sealed openings, HAVS monitoring and class M vacuum cleaning. The iron stair was repaired and repainted, missing and damaged boards were replaced, and an experienced conservator was commissioned to create a new iron handrail to suit the existing balusters.
Balustrade works were carried out to the upper landing and the bottom of the staircase, helping improve safety while respecting the character of the historic structure.
Soffit Repairs and Concrete Deck Works
Internal birdcage scaffolding was installed to provide safe access for soffit repairs. Exposed iron joists within the concrete decks were cleaned and treated with a proprietary corrosion inhibitor, including zinc-rich primer where required.
New steel framing and underdrawings were supplied and fitted, including fixings, joints and stainless-steel mesh underdrawings to the soffit. During templating, it became apparent that the steel sections could not be installed exactly as drawn. A site meeting was promptly arranged, an agreed alteration was developed, and a revised template was produced. The steel channel was fabricated and dry fitted to confirm correct fitment, avoiding unnecessary downtime and ensuring the repair was practical, durable and buildable.
Access, Logistics and Working Within the West Pennine Moors SSSI
Darwen Tower’s position on Darwen Moor created major logistical challenges. To facilitate scaffold, welfare and material access, a controlled access route was established from Belgrave Road. Vehicle movements were carefully managed, with banksmen and two-way communication used to maintain public access and protect walkers using the moor.
Passing points were restricted to existing hardstanding, with no encroachment onto the moorland. Materials were delivered on a phased basis to reduce vehicle movements, and specialist vehicles including a 4×4, Polaris-type vehicle and in-house fabricated trailer were used to transport scaffold and materials to the tower. In some instances, the team transported up to two tonnes of scaffolding and materials across difficult terrain.
The immediate working area was managed to minimise impact on the surrounding landscape. Track mats were installed to protect ground conditions, materials were stored securely within the compound, and waste was bagged, removed and managed in accordance with the project’s waste procedures.
Ecological protection was a key part of the project. The site is located within the West Pennine Moors SSSI, with potential constraints relating to bats, ground nesting birds and sensitive moorland habitats. Operatives received ecological briefings and toolbox talks, access was restricted to agreed routes, and the team worked in accordance with the ecological method statement and Natural England requirements.
Scaffold Design, Weather Protection and Site Security
The scaffold design was a critical component of the project. Due to the tower’s height, octagonal form and extreme wind exposure, UK Restoration Services took a proactive approach and recommended that the scaffold incorporate 40 tonnes of kentledge, arranged through four scaffold pads around the structure. Shrink wrapping and metal hoarding were installed to provide weather protection and help reduce unauthorised access.
Despite these precautions, the site experienced repeated periods of severe weather, including high winds, heavy rain, snow and storm conditions. Works were paused when conditions became unsafe, scaffold inspections were carried out following adverse weather events, and the site team returned out of hours where necessary to secure loose hoarding or sheeting.
The tower was also vulnerable to vandalism and break-ins. In response, 5m metal hoarding was installed to the base of the scaffold, additional fixings were introduced, and site surveillance procedures were implemented during shutdown periods. Regular inspections were carried out to check fencing, hoarding, scaffold sheeting, scaffold condition and the tower itself.
Health, Safety and Public Interface
Public safety was a major consideration throughout the works. Darwen Tower remained a highly visible landmark and the surrounding moor continued to attract walkers and visitors. Site boundaries, warning signage, controlled access arrangements and daily coordination were essential in separating the works from public routes.
No environmental incidents, close calls or near misses were recorded across multiple reporting periods, despite the exposed and challenging working conditions. Weekly health and safety analysis, scaffold inspections, toolbox talks, site inductions and task-specific method statements formed part of the project management approach.
Hot works, asphalt repairs, lime works, lead paint removal, working at height, adverse weather, ecological constraints and public interface were all managed through appropriate risk assessments and method statements.
Conservation-Led Problem Solving
The project required a responsive and collaborative approach throughout. As hidden conditions were uncovered, including deeper masonry voids, loose units, corroded dog cramps to the parapet and constraints around soffit steelwork, the team worked closely with the client and professional team to agree suitable solutions.
Original mortar was sent for specialist analysis to inform the pointing specification, and revised methodologies were developed where trialled approaches were not suitable. For example, a test using a mortar gun and wet pointing mix with casein was trialled to assess whether deep voids could be filled using that method, but was deemed unsuitable. The project then progressed using a more appropriate deep tamping and grouting approach.
The combination of site trials, sample panels, monitoring, conservation input and practical site experience ensured that the repairs were technically sound, visually appropriate and suited to the long-term demands of the structure.
Project Outcome
Practical Completion was achieved in July 2022. The completed works have stabilised and conserved the historic fabric of Darwen Jubilee Tower, improved rainwater management, repaired key masonry and metalwork elements, and enhanced the long-term durability of the tower in its exposed moorland setting.
The project is a strong example of specialist heritage restoration in Lancashire, combining traditional lime-based repair techniques with modern project management, carefully controlled access, environmental protection and close collaboration with the professional team.
