The Wilton International Site (Wilton Site) is a large chemical plant complex, of some 930 hectares in total. Developed by ICI after the Second World War and situated on the south bank of the River Tees, it is bounded on other elevations by a combination of residential, commercial and agricultural properties. The Plant is located to the southeast of the Wilton International site, the Plant was commissioned in 1969 and taken out of service in 1982. On closure the plants were not fully decommissioned, as there was a belief the plant may be restarted; however, this idea was abandoned in the early 1990s.
The site remains ‘operational’ throughout the duration of our works so there is a requirement to manage frequent pedestrian and vehicular movements adjacent to our work area.
The Works being undertaken on the site comprise of the removal of hazardous insulating material, decontamination, demolition of various process plant structures, pipework/cables/pipe bridges, plant and equipment, and was inclusive of:-
- Fully intrusive structural investigation of the existing design of all buildings and structures
- Pre and post demolition CCTV drainage surveys
- Provision of a method to weigh waste leaving site
- Removal and disposal of all asbestos containing/other hazardous materials prior to the demolition of each structure / area of process plant with such specialist activities undertaken by Keltbray’s in-house asbestos removal division Keltbray Environmental Solutions (KES); these works have included various trials to ascertain the safest possible working procedure for removal under appropriately controlled conditions.
- Recovery and disposal of residual product in all process plant/equipment; due to the nature of the chemicals processed it was not possible to fully decontaminate all equipment, Keltbray therefore needed to allow for the presence of residual product in all process equipment until proven otherwise.
- Environmental clean and appropriate decontamination/disposal of pigeon droppings and carcasses.
- Soft stripping of all levels of individual demolition
- Demolition of identified individual work packages leaving in place all concrete plinths/up stands; this includes the Demolition of a 63 metre high cooling tower and a 93 metre high chimney bounded on three sides by live operational process equipment. A combination of controlled hand demolition, dismantling and remote mechanical demolition is being utilised to safely remove redundant assets which are in a badly corroded condition due to the age of the plant.
- The plugging and sealing of redundant underground pipework/sewer connections.
- Backfilling, compaction and grading of any hollows to surrounding ground floor slab level
- The removal from Site of all other demolition materials.
Weekly Hazard and Operational (HAZOP) meetings are held to offer a structured and systematic examination of the ongoing and planned works in order to identify and evaluate problems that may represent risks to personnel or equipment, therefore ensuring that risks are highlighted and control measures put in place to mitigate risk where possible. This includes for upfront characterisation of process materials which are anticipated to be encountered throughout the plant, allowing for sufficient COSHH assessments to be carried out and control measures implemented to protect operatives at the work face.
Keltbray’s project team are working closely with our in-house consulting engineers Wentworth House Partnership (WHP) to ensure that engineering assessments are carried out into the work-ability of each demolition method and agreement reached on the sequence of works to ensure the lateral stability of various adjoining structures is maintained at all times throughout the demolition works.
