The Welsh Assembly Government
Demolition of the Former Corus Steelworks, Newport, South WalesFollowing a stringent pre-qualification process and competitive tender the Welsh Assembly Government (WAG) appointed Connell Brothers Ltd to carry out the demolition which forms part of the Regeneration of the former Corus, Whitehead Steelworks in Maesglas, Newport.
It was a 27 acre site which was surrounded by neighbours and in a sensitive location. This included, on the Northern boundary, the Royal Gwent Hospital, on the eastern boundary, the Mendalgief Road which comprises densely populated residential properties with nursing home for the elderly and local school.
To the west an adjoining operational manufacturing site belonging to BRC and Coil Colour. The southern elevation comprised of a retail park with several large multiple chain operators, which also provided access into the demolition site.
The site’s previous use was that of a heavy industrial steel manufacturing plant.
The client’s main objective was to clear the site of all buildings and any surface contaminants associated with the site’s previous use. The client’s requirement was to clear the site in two phases.
Phase 1 comprised the North Site, Phase 2 comprised the South site, Godins Building & Decker Building. (Following Owens Transport leaving the site in June 2008)
The scope of works comprised of;
Liaising with WAG appointed Ornithologist and Installation of bird kites to prevent seagulls from nesting on site.
Liaison with numerous service providers on the progress of various service disconnections required for the site. Further liaison was also required with the Electricity Supplier on the prevention measures required whilst carrying out demolition around the LIVE Substation located centrally to the site and which had to remain after completion of the works.
Liaison with the occupiers of the South site, Owens Transport with regards to their vehicle movements and access arrangements.
Liaison with the Royal Gwent NHS Hospital for the demolition of the former Archive Building. This building was located adjacent to land utilised by personnel from the Royal Gwent NHS Hospital for car parking with the access road running along the front of the building for demolition. An agreed programme was established for carrying out the works when the car park was not in use over the weekends. At the completion of each weekend’s works, areas were cleaned off and all roadways re-opened for NHS staff to resume parking during week days.
Stripping out the site of all loose redundant fixtures and fittings
Removal of all asbestos containing materials as identified in the Type 3 Survey. The removal required the construction of enclosures for all notifiable works and controlled removal for non notifiable works.
Due to the location of the site adjacent to the Hospital and residential areas, a regime of background / perimeter monitoring was established prior to the commencement of any works. Once works commenced the background / perimeter monitoring continued with the additional of personal monitoring for employees. Results of the monitoring demonstrated that there were no fibre releases throughout the works.
Collection of chemical drums left behind by previous owners into a quarantine area. Identifying, cataloguing, labelling and packaging the chemicals prior to disposal to their designated licensed landfill sites.
Extensive cleaning of the heavy oiled floor slabs, machine bases and pits etc. prior to any demolition being commenced. The site also contained numerous pits and sumps associated with the production of steel. Over the years these had become heavily contaminated and required chemical cleaning, prior to backfilling with clean stone. All the run off from the cleaning operations were contained to avoid contamination of the local watercourse adjacent to the site.
Removal of heavy oils from existing storage tanks, decanting and disposal off site for recycling, prior to cleaning of tanks for disposal of site as scrap material.
Operatives equipped with full disposable PPE carried out a full Environmental clean of the buildings to remove heavy deposits of Bird Guano.
Cement bonded asbestos sheeting forming the roof to the majority of the structures was removed by operatives wearing PPE including disposable overalls and half face masks with P3 filters working from mobile elevated working platforms and wearing harnesses securely anchored. Sheets were removed whole and brought to ground level, placed into previously enveloped skips ready for dispatch to licensed tip facility.
Marking the position of voids and basements prior to demolition and communicating to the workforce to ensure no machines travelled over any suspended areas or basements was of paramount importance.
Once all the areas had been passed of a chemically clean and free of asbestos demolition commenced employing specialist high reach machines (70 tonne) assisted by smaller machines (50t, 30t 33t 25t 20t) to process the arrisings.
The structures generally comprised of large industrial bays with steel trusses carried on steel columns. The majority of bays included overhead cranes on crane rails.
- Phase 1 – Demolition of North Site comprising;
– Manufacturing Bays 3, 4, 5, 6, 7, 8 and 9.
– Manufacturing Bay 10 with one wall forming retaining wall to the LIVE Substation.
– Billet Yard Buildings
– Galvanising Workshop
– Oil Stores Building
– Main Stores Building
– Archive Building.
- Phase 2 – Demolition of South Site comprising;
– Godins Paint Plant
– Godins Office Buildings
– Godins Main Area. (This entire building was located on a suspended floor slab with basement)
– Decker Building
– Carpenters Shop.
Phase 1 works proceeded in accordance with the programme. The main areas were levelled off with all high spots being battered back with site won materials.
Upon completion of the demolition of the Billet Yard Buildings there was a requirement for the re-cladding of the interface with the BRC and Coilcolor. A cladding support system was erected on the existing steel frame and new profile sheet cladding installed along this elevation to maintain the integrity of the building fabric.
Phase 2 works; Owens Transport vacated the Godins / Decker area as agreed in June 2008. During the asbestos removal works to the building suspect sprayed on material was discovered to the Decker Building. This material was sampled and proved to be positive as sprayed asbestos. The material was sandwiched between the inner and outer cladding sheets to the walls of the Decker Building. Works to this area stopped immediately and revised methods of work adopted along with notifications to the HSE.
The project involved the construction of internal within the building and external enclosures within the scaffold 7.9 metres high to ensure no release of fibres during the removal works. As a further preventative measure the building required fully encapsulating with scaffolding and flame retardant Monaflex sheeting. Due to the proximity of the residential properties further monitoring was undertaken at the boundary to ensure fibre release did not exceed the specified control limits.
In an attempt to minimise any delay to the programme, a structural assessment was undertaken. This allowed the separation of the Godins Building from the Decker Building, enabling the remainder of the structure to be demolished without any impact on the remaining structure from vibration.
The Godins Building covered approximately 11,000 m2 and presented a number of challenges for demolition.
This structure contained a basement which was unable to withstand the weight of demolition machinery. In order to demolish the main structure, a number of add-on structures were removed first to gain access to the main structure. This structure was of a “3 pin portal frame” type and contained a number of inset lantern bays to introduce natural light to the building.
In order to carry out the demolition of this building the lantern bays required removing in a systematic manner to isolate each 3 pin bay. Once each 3 pin bay was isolated the steelwork was pre-cut at previously calculated locations and the entire bay was lowered down onto the ground floor slab in a controlled manner by the use of excavators positioned within the adjacent car park. The bay could then be removed from the slab without the need for any heavy plant to enter the building and processed for removal from site.
The remainder of the asbestos works were now completed and awaiting the final 4 stage clearance on the Decker Building, allowing for its demolition.
The site was subject to numerous visits and audits by external parties and no non-conformances were noted. (Health & Safety Executive, ARCA, Hyder Consulting, Wilkinson Associates,)