On the 31st July 2002, Ebbw Vale Works closed its gates as an operational site for the final time, this is the next chapter in the remarkable story of the Works that had commenced an iron & steel making operation in 1790.

The demolition of the Works is the first phase in regeneration of the Ebbw valley as it makes a step change from its heritage as a world leader in the manufacture of iron and steel, to its future development as defined by the Master plan.

Following the closure announcement in February 2001, sixteen Decommissioning Managers/Engineers (Bottom of this page) were selected for their expertise in their specific plant areas, they would be responsible for all aspects of planning and de-commissioning plant within their area. The planning process included the allocation of resources and manpower to achieve de-commissioning of the site within a three-month window. Each area was broken down from the plant register of equipment to its particular plant identification number to ensure all items of plant and equipment would be included in the planning programme and subsequently decommissioned.

It was recognised from the early planning stage that an item of kit de-commissioned post closure may not be demolished for up to three years following closure. Therefore, it was essential from a health and safety perspective to ensure all kit was de-commissioned and recorded as such in the de-commissioning log for the specific plant area, e.g. all equipment with the potential to store motive power, such as a belt wrapper, would be decommissioned and isolated in the lowered position. Pre-closure planning also included the reduction of chemical and oil stocks to minimise the waste of raw materials. First phase de-commissioning of the production units by line crews, i.e. dumping of line solutions to the Effluent Plant, as lines shut down, prior to plant closure.

Specific targets were set by producing Risk Assessment and Job Method Statements for each individual system identified by the plant register within the production unit.

Targets were set for de-commissioning of chemical, oil, cooling and gas systems etc. Also to ensure safety standards were maintained during the de-commissioning process, the Risk Assessment and Job Method Statements identified all safety aspects associated with each individual plant item to be de-commissioned.

For example: isolation procedures for electrical and stored energy systems, personal protective equipment requirements, standard working practices, and COSHH (Control of Substances Hazardous to Health) Assessments. Electrical, steam and compressed air systems were all de-commissioned by switching off at source by specific specialist engineers within the de-commissioning team, e.g.

electrical supply was switched off at the central sub-sfation. Similarly, a specialist contractor purged the natural gas system with nitrogen, to prevent the risk of explosion or fire during the demolition phase.

Fifty CPP personnel, retained under the supervision of the Decommissioning Managers, achieved de-commissioning in a three-month period from August to October 2002. Primarily they were split into three teams, with appropriate Welfare facilities and safety meeting rooms, based on their previous plant location and experience. With the North (Coating personnel) and South (Rolling personnel) Teams being responsible for the physical de-commissioning of the site systems assisted by the fifty on-site mechanical contractor personnel. The Warehouse Team, as the name implies, were responsible for the shipping of some 20,000 tonnes of stock to customers and subsequently de-commissioning of the Warehouse area. One of the main objectives set by the De-commissioning Team was to minimise, wherever practicably possible, the amount of waste produced by decommissioning. This was achieved by recovering and recycling of hydraulic oils, tin (electrolyte) sludge; similarly, raw materials such as chemicals and oils were transferred to other Corus sites. Items such as office furniture and laboratory equipment being donated to local schools. All liquid waste produced by the de-commissioning process was processed through the on-site Effluent Plant to comply with the Environment Agency discharge consent limits. While all waste arisings disposed to landfill or licensed treatment facilities complied with the relevant Waste Management Regulations.
Ultimately De-commissioning Managers would form the Closure Team, and would be responsible for managing the demolition of their specific areas, therefore ensuring continuity between the de-commissioning and demolition phases of the project.

In parallel with the de-commissioning process, the De-commissioning Managers were also responsible for managing the removal and transfer of assets to other Corus sites. The main objective of the asset disposal programme was to manage the transfer of redundant assets within the CPP/Corus businesses, to maximise the benefit of the asset to Corus and improve performance and productivity at other sites. Three options were evaluated in the process of maximising the benefit to Corus, firstly the transfer of assets (plant, equipment and spares) within the Corus businesses; secondly, external sale of the asset through an appointed agent. Finally, if the first two options were not achievable, the equipment and spares would be scrapped as part of the demolition process. Prior to closure both 4 ETL and the D.R. Mill were transferred to Trostre and Ijmuiden respectively, while post closure the Galvanising Line and Lurgi acid recovery plant were transferred to India.

The site covers approximately 189 acres and is secured by 5.5 km of 2111 high palisade fencing; to maintain security standards CPP security staff' were retained throughout the demolition programme. The post closure security envelope implemented on site closure included erecting an additional 1 kilometre of fence to isolate the southern end of the site, further fencing was erected at potentially intrusive points and visual black-spots.
All site buildings were secured by permanent closures fitted to windows and doors, with locks being fitted to all access doors for closure outside normal working hours.

A substantial investment was made in installing a 'state of the art' CCTV system with 3600 rotational movement, infra-red night vision and continuous recording capability, with the 10 CCTV cameras focused primarily on monitoring the perimeter fence. To control personal and vehicle entrance, access was restricted through one main gate with all other external gates being permanently sealed. To inform members of the public, in particular children, warning signs both written and visual were erected at 50m intervals on the perimeter fence, specifically warning of the dangers of a demolition site.

Throughout the pre-closure and post closure periods regular meetings were held with the Corus Security Department, Police and Fire Brigade, to establish best practice in security of the site, with the main aim to prevent access to children on what would become a potentially dangerous demolition site.

To fulfil its environmental obligations CPP appointed an independent Environmental Consultant to undertake a land quality investigation. The initial desktop study involved the collection of all relevant historical and environmental information. This study highlighted the potential land quality issues associated with the Ebbw Valley's long operational history of iron & steel making, as well as relating to the known activities associated with processing tinplate and galvanised products. This was followed by an intrusive investigation of the potential contaminated areas, in total some 85 bore holes and trial pits were sunk and samples taken and analysed to evaluate ground and groundwater conditions. The site investigation report was circulated and discussed in liaison meetings with the Environment Agency. It was accepted by the Agency that the site conditions did not present a significant risk to the local environment, and there would be no environmental impact from the demolition of the site.

A further investigation was undertaken into the groundwater and surface water interaction on the site, to assess the impact of water arisings from historical mine workings on and off the site. The investigation and subsequent reports were discussed, issued and accepted by both the Environment Agency and Local Authority that there was no major impact on the River Ebbw Fawr from groundwater and surface water interaction associated from both on and off site activities. Borehole water quality monitoring and river water analysis continued throughout the demolition process to ensure there was no environmental impact from the demolition of the site.

Corus and David Morton produced a bi-monthly Newsletter that was circulated to members of the Local Authority, and within the local community through the Post Office and local Newsagents. The Newsletter informed the community of progress with the demolition of the site and the future planned demolition works. The demolition was also visually demonstrated with the use of photographs. Feedback from the local community was very positive on the content of the Newsletter. This was probably best demonstrated by the co-operation received from the residents of Tyllwyn during the explosive demolition collapse of the Pickle Line.

The demolition process produced some 95,000 tonnes of scrap metal, 11,500 tonnes of waste (of which 10,000 tonnes was inert or non-hazardous), while crushed brick and concrete produced 28,000 tonnes, which was used to fill holes and voids on site. This was mostly achieved by some 20 mechanical machines comprising high reach shears, ground shears, mobile magnet crane, various crabs, scrap baler, brick crusher, loading shovels, lorries, rear dump trucks and a drag line crane, specifically purchased to remove kit and equipment from the basements.

The manpower varied through the contract depending on the type of demolition work, it was undertaken by a core of some 25 to 30 demolition personnel, which peaked for a period of 4 months to 65 personnel for removal of kit and equipment from the basements. The Industrial Cleaning contractor had a manning level of 10 personnel undertaking cleaning work de-contaminating basements such as V-Stand, D.R. Mill, Temper Mill etc. The initial de-commissioning team of 50 Corus personnel and 50 mechanical contractor personnel were retained for a period of 3 to 6 months to de-commission the site in 2002. This was supported by a 16-man closure team and a 14-man security team, manpower numbers were subsequently reduced in line with progress against the demolition programme; in total some 517,000 man hours were worked in clearing the site.

To make the site safe and environmentally secure, the civil works involved the sealing of all entrances to basements with pre-cast concrete units for 160 floor openings classed as major holes, while circa 400 depressions being filled with some 28,000 tonnes of site generated rubble. The civil works also included the construction of a basement hydrology system, based on five catchment areas, within the basement system, designed by an independent hydrologist, which utilised the underground basement and tunnels to channel water to the existing site interceptor system. This wou Id then be monitored prior to discharge to the river, in the event of pollution being detected the discharge would be re-directed to the Effluent Plant for treatment before discharge to the River Ebbw Fawr. The system was designed to cope with the worst case storm of 1 in 100 years.

The most challenging and dramatic demolition sequence undertaken during the three-year demolition programme of the Works was the explosive demolition collapse of No: 4 Pickle Line.

The Pickle Line was constructed in the early seventies and was built some 20 metres above the valley floor running east to west, the only production process in the Works that operated in this direction. The Line was also constructed above the River Ebbw culvert that runs in a southerly direction for approximately 1 mile under the Works, beneath the lower Effluent Plant road that also passes under the former Hot Mill Bridge.

Conventional demolition techniques of cut and collapse was considered but rejected, on grounds of health and safety to demolition personnel and the long-term disturbance to the residents of Tyllwyn. Also considered was the removal of the Line's process equipment, pickling tanks etc. from the building by collapsing the tanks and internal structure inside the building and removing through the exit end (west side) of the Line. This was also rejected as the Pickle Line's mezzanine floor would not take the weight loading of the demolition machinery; also, the building structure would still have had to be collapsed to floor level to be safely dismantled.

Several discussions were held with an independent demolition explosive consultant to decide the preferred methodology of collapsing the Pickle Line using explosive charges to kick out the main supporting steel legs.

Initial discussions were based on collapsing the Pickle Line in four different sections, from south to north, starting from the exit end (west side), to leave the final section (entry end) standing to minimise the effect on Tyllwyn. After clearing away the previous collapsed structures, the final section would then be collapsed in a westerly direction away from Tyllwyn. However, due to the design of the integral steel structure there was a possibility that the collapse would not be successful, the demolition consultant would not guarantee that some sections of the building would not "stand-up", i.e. sections could remain partially suspended. Eventually, following a lengthy debate on the best methodology to collapse the Line in the safest manner, with the minimum impact on Tyllwyn, it was decided that the Line would be demolished in one sequence, with only the exit end (west side) which stands on solid ground on the Cold Mill plateau left standing; the whole programme was then carefully planned.

Following the decision to collapse the Line by utilising explosives, a consultation process was initiated with the Tyllwyn Residents Group, Local Councillors, Police and the Highways Authority, to keep them fully informed of the sequence of events leading up to the demolition.

While the explosive consultant was responsible for drawing up the plans, risk assessments and method statements for pre-weakening the steel structure and placement of explosive at the steel colunm bases, all other aspects of planning the demolition programme were the responsibility of Corns and David Morton Ltd.

The building structure had to be collapsed in a northerly direction, as the site drainage pump house located a couple of metres south of the Line was to be retained. Similarly, the river culvert which runs directly below the Line had to be protected, with a metre of crushed brick being spread over the roads above the culvert to absorb the impact of the falling structure, the position of the Hot Mill Bridge would also assist in cushioning the impact of the falling building on the culvert.

To ensure the building would collapse as planned, all the external cladding and structures below the mezzanine floor were removed to expose the steel
legs, with the north legs being pre-cut/weakened at ground floor level, while the south legs were pre-cut/weakened just below the mezzanine floor. The sequence of collapse was designed for the north legs to kick out first, half of the legs in an easterly direction and the other half in a westerly direction, followed by the south legs; so that the building structure above the mezzaine floor would collapse and slip-off the floor and fall in a northerly direction.
Air over pressure wave calculations indicated that there would be no blast damage to property in Tyllwyn; however, in the interest of safety a 150 metre exclusion zone was established around the blast area, as this would encompass part of Tyllwyn, 45 houses in Clovelly A venue and Ash Grove would have to be evacuated as a precautionary safety measure.

Following consultation with the Tyllwyn Residents Group and the local Councillors, the residents of the 45 houses to be evacuated were personally visited and the demolition procedure explained. Each household was handed a specific newsletter and asked to complete a simple questionnaire, i.e. how many people lived in the property, their whereabouts on the day of the blast, would they require transport (particularly the elderly) to Lever Hall, where refreshments would be provided, emergency contact numbers if the occupier was out on the day, in the event of unforeseen circumstances. A viewing area was established in front of East Ville Terrace on the boundary of the exclusion zone specifically for the residents of Tyllwyn and members of the media.

To minimise the effect of the blast wave some 6,000 sandbags were placed around the steel legs to absorb the initial blast wave from 75 kilos (165 lbs) of nitro-glycerine required to collapse the building. The sandbags, plus the bund walls of crushed brick constructed along the eastern fence line directly opposite Clovelly Avenue, were designed to absorb and disseminate the blast wave and prevent damage to property. Ground vibration analysis would also be undertaken on the day to measure the impact of the collapsing structure.

As Steelworks Road runs through Tyllwyn and was within the blast exclusion zone, discussions were held with the local Police Inspector and the Highways Department to close the road for approximately 2 hours while the building was collapsed, to prevent traffic entering the exclusion zone.
The road was closed at the General Office and Waunllwyd, this would be undertaken by the Police Inspector supported by 9 Police Officers.
Nine security marshals were located on the perimeter of the exclusion zone around Tyllwyn, while a further six marshals were located within the, Works, all in radio contact with the blast control centre at the West Gate.

Only when the security marshals had confirmed that the exclusion zone was clear would the 10 minute all-clear warning hooter be sounded and the final countdown On the 13th March 2004, with the explosive charges in place, all houses evacuated, roads closed, the press and media gathered to record the Line being blown down, all blast control personnel in their designated positions, the final countdown was commenced by sounding the 10 minute all-clear hooter. On confirmation by the marshals that area was still clear at 1 minute, the hooter was again sounded to commence the final 10-second countdown. The red button was then pressed on the control box to send an electric charge to set-off the explosives in their designed sequence; to the cheer of the crowds, the line then collapsed in a matter of seconds, removing a significant landmark which had dominated the Works and the Ebbw Valley skyline for some 30 years.

No damage to property in Tyllwyn was incurred, not a single window broken, this was supported by ground vibration monitoring that recorded minimum impact on the surrounding area, caused by the collapsing building.

Corus and David Morton Ltd. are indebted to the residents of Tyllwyn for their support and co-operation throughout the planned demolition sequence of the Pickle Line.

D. M. James - Closure Team Manager
A. O'Neill - Project Manager
D. J. Jones - Project Safety Engineer
L. Pritchard - Project Accountant
P. Jaynes - Project Secretary

M. K. Lewis - Project Electrical Engineer

W. Granville - Project Mechanical Engineers
J. Sugrue
D. Evans
D. J. Owens
D. Meyrick

M. Atkinson - Project Civil Engineer
M. D. Stone - Project Engineer & Statutory Inspection
P. Holloway - Project Resources Administrator

S. Wilce
P. Morgan - Project Water & Effluent Engineers
D. Powell