CASE STUDY 5
Client
Stena Line
Project type
Explosives demolition following pre-weakening.
Building types
122m-high concrete chimney with internal steel flue
Four steel frame smelting storage sheds (480m long x 22m wide), clad in aluminium
Value of project
£400k
Timescale of project
15 weeks
SUMMARY OF PROJECT
TRD was appointed by Stena Line to undertake the full demolition of the former Anglesey Aluminium smelting plant in Holyhead, North Wales. Once a cornerstone of British industry, the site had been dormant since its closure in 2013. At its peak, Anglesey Aluminium produced over 140,000 tonnes of aluminium annually and was the largest single user of electricity in the UK, consuming approximately 255 megawatts per year.
The demolition scope included four large steel-framed storage sheds, the remaining smelting works, and a towering 122-metre reinforced concrete chimney-a local landmark that had dominated the skyline for over 50 years. The project formed part of a wider regeneration initiative linked to the Anglesey Freeport, with the cleared land earmarked for future investment and development.
Our works involved:
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Full site clearance including four steel-framed sheds and smelting works;
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Pre-demolition asbestos survey and decontamination;
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Soft strip of internal structures;
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Controlled explosive demolition of the 122m chimney;
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Processing and removal of arisings from site;
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Coordination with multiple agencies including RAF, Network Rail, and highways
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All personnel equipped with the latest PPE, with regular safety briefings conducted to maintain high safety standards.
Our specialist capabilities:
Controlled explosive demolition, safety and speed of execution, environmental compliance, multi-agency coordination (Mike Kehoe of C&D Engineering Consultants, Network Rail, the Royal Air Force, Fire and Police Authorities and Traffic Wales), minimal disruption to surrounding infrastructure.
The Chimney: Engineering a Landmark Collapse
The demolition of the 122-metre chimney-one of the tallest structures in Wales-was the centerpiece of the project. Constructed with a reinforced concrete shell and internal steel flue (known as the Carbon Baking Stack), the chimney required extensive pre-weakening to ensure a safe and predictable collapse.
TRD’s engineering team executed the following:
– 156 diamond-drilled holes in a precise pattern
– Each hole packed with 125g of Perunite, a TNT-based explosive known for its high detonation velocity and energy density
– Total explosive load: 19.5kg, connected via 120 metres of detonating cord to a central firing point
– A large section of reinforcement was cut from the northwest face to guide the trajectory
– A “window” was formed in the southeast face to direct the fall
– Existing doorways and openings at the base served as engineered “hinges”
Due to the site’s proximity to RAF Valley airspace, Network Rail passenger and freight lines, and major roads including the A5 and A55, TRD was granted a 15-minute operational window to execute the blast. The demolition was carried out on 20 March 2024, following 15 weeks of enabling works, and was completed flawlessly.
Site Clearance & Environmental Management
Beyond the chimney, TRD dismantled four steel portal-framed sheds clad in aluminium, along with the remaining smelting infrastructure. All materials were processed and removed in accordance with environmental regulations. Dust suppression, exclusion zones, and traffic management were deployed throughout the project to minimise disruption to the local community.
Outcome
The project was delivered on time and to specification, with zero incidents and full compliance across safety and environmental standards. The successful demolition of the chimney marked the end of an industrial era and the beginning of a new chapter for the Anglesey Freeport.
TRD’s work was praised for its precision, professionalism, and collaborative approach-bringing together engineering expertise, logistical coordination, and community care.
This project was prominently featured in the nationwide press and media, notably on BBC News and Sky News.