Case Studies for Urban & Residential
Explosive Demolition of Mildane & Ashthorpe Tower Block at Hull’s Orchard Park Estate
Description of Works
Following a competitive tender Robinson & Birdsell Ltd were appointed by Hull City Council to demolish two tower blocks, Milldane and Ashthorpe, by the controlled use of explosives engineering. The blocks were situated on Hull’s Orchard Park Estate and were twenty two and twenty storeys respectively.
A decision was taken during the design phase, by Robinson & Birdsell Ltd, to carry out the explosive demolition of both tower blocks simultaneously. This, in turn, created a commercial saving for the client by minimising the ‘on the day’ evacuation costs, with the added benefit of reducing the environmental impact and disturbance to the residents.
Extensive soft strip was completed, as per programme, to allow the pre-weakening process to be undertaken to the five identified blast floors on both structures. This element of the works was designed by our in-house Explosives Engineer in conjunction with an independent structural engineer.
The evacuation of the safety exclusion zones was designed in preparation for the blowdown day. From the outset, a Resident Liaison Officer was appointed to act as a direct link between all three hundred and four residential properties, stakeholders and other third parties. Regular resident drop-in meetings were held to answer any questions and queries. A bespoke website was also developed to share the works information with residents in order to maintain regular communication to reassure and ease any concerns.
On each of the blast floors, approximately eighty holes were drilled for the explosive charges, with a further ninety holes on the ground floor, totalling four hundred and ninety on each structure. To connect all the explosives together required five hundred metres of detonation tube and five hundred and fifty detonators/ delays per block.
On the day of the blowdown the evacuation of the safety exclusion zones were manned by a total of forty six SIS trained security guards, with an additional twenty six traffic and beat officers provided by the police. The exclusion zones required the evacuation of over eight hundred people by Robinson & Birdsell Ltd’s liaison team, along with additional staff provided by the local housing authority, to a nearby evacuation centre. Entertainment and refreshments were on hand for those requiring it. The evacuation commenced at 08:00 with both zones taking around three hours to clear, providing a completely unoccupied zone prior to blowdown.
Ten minutes before blowdown a number of main roads were temporarily closed by the police to enforce the exclusion zones and minimise any risk and inconvenience to traffic. The event took place at 12:00 and the clean-up commenced at 12:10 and utilised several road sweepers along with a number of mobile jet washing units. The area was sufficiently sanitised and both debris piles civilised and safe by 13:15 enabling residents to return into their properties with minimal inconvenience.
Meanwhile the safety exclusion zones were lifted and the crowd barriers collected.
In conclusion, the project was completed safely, without any environmental or safety incidents and to the total satisfaction of our client, local community and immediate businesses, in line with a Waste and Resources Action Programme (WRAP) and demolition protocol. Robinson & Birdsell Ltd recycled 97% of the entire buildings and their contents, in line with our recycling targets.
Location: Orchard Park Estate, Hull
Scope: Explosive demolition and final clearance of two high rise city dwellings
Client: Hull City Council/ NPS
Explosive Demolition and Site Clearance of High Rise City Dwelling
Description of Works:
Falcon Court was the last remaining tower block in a group of four associated with the Old Trafford Regeneration Masterplan, three of which were demolished by Robinson & Birdsell Ltd using long reach demolition on earlier dates. The client, however, wanted to commence the redevelopment of the area by making a ‘significant bang’, and therefore requested Robinson & Birdsell Ltd to undertake the final block using the controlled use of explosives.
The collapse mechanism was designed by our own in-house Explosives Engineer checked and endorsed by an independent structural engineer, prior to the commencement of any pre-weakening works.
The 1970’s built structure was first subject to a demolition and refurbishment survey, therefore the first phase of the works was to remove all identified asbestos. The structure also housed a live sub-station which was due to be terminated and removed one week prior to blowdown. However, as the team began removal of the sub-station additional asbestos was identified. This was a result of the sub-station caveat, as it did not form part of the original survey due to access restrictions. Fortunately, due to Robinson & Birdsell Ltd having invited the Health and Safety Executive to site from commencement of the works we had formed a good working relationship and a waiver was given allowing the additional removal works to be undertaken without delaying the blowdown date already agreed with all the relevant stakeholders.
Following on from the initial asbestos removal phase, an extensive soft strip was completed in accordance with the programme, to allow the pre-weakening process to be undertaken to the four identified blast floors. A total of thirty four pre-weakening breakouts were made as well as the removal of all internal non load bearing walls. Following on from pre-weakening a total of three hundred and ninety eight holes were drilled to accept the explosive charges.
Regular resident drop-in meetings were held to answer any questions and queries. Planning and co-ordination meetings were also underway in the background during all of the above work phases to ensure a successful blowdown day.
A total of fifty five residents were displaced to a nearby evacuation centre as a result of implementing the safety exclusion on the day. The evacuation was undertaken by Trafford Housing Trust with support from Robinson & Birdsell Ltd’s liaison team. Ten minutes prior to blowdown a number of main roads were temporarily closed by the police to enforce the exclusion zone and minimise any risk and inconvenience to traffic.
All residents were evacuated sympathetically and on time as per Robinson & Birdsell Ltd’s blowdown planning. The demolition was successfully undertaken at 12:00 with the clean-up commencing at 12:10. The area was sufficiently clean and debris pile civilised and safe by 13:00 enabling residents back into their properties with minimal inconvenience.
The demolition works and blowdown were also featured on the BBC’s Blue Peter programme with members of Robinson & Birdsell Ltd’s explosives team assisting in its making. All the work was filmed including the community liaison aspect and Falcon Court finally succumbed in a ‘text book’ collapse, on programme, with minimal inconvenience and without incident.
The project was completed, without any environmental or safety incidents, and to the total satisfaction of the client, local community and immediate businesses in line with a Waste and Resource Action Programme (WRAP) and demolition protocol. Robinson & Birdsell Ltd recycled 98% of the entire buildings and their contents, in line with our recycling targets.
Location: Falcon Court, Tamworth Estate, Old Trafford, Manchester
Scope: Explosives demolition and site clearance of a fourteen storey tower block
Client: Trafford Housing Trust
Explosive Demolition and Final Clearance of 20 Storey City Centre Tower Block
Highcourt was a 59 metre tall, 20 storey tower block located on Hull’s Orchard Park Estate. The block was the tallest building in Hull and the last surviving high-rise block on the estate. The tower was demolished as part of the Hull City Council Regeneration Masterplan, two of which were demolished simultaneously by Robinson & Birdsell using explosive means at earlier dates.
Robinson & Birdsell’s in-house Explosives Engineer, John Turner undertook to bring down the final 20 storey tower block using the controlled use of explosives.
To carry out the blast in a safe and controlled manner the collapse design required 1170 holes to be drilled, following 20 pre-weakening break out’s of each of the 5 blast floors. A total of 1170 detonators initiated a total of 48.5kgs of explosives over 5 delays from 300 milliseconds to 1000 milliseconds to reduce the air overpressure. The preparation works for the explosives took 3 months including the final protection measures both at source and secondary.
Come blowdown day, a total of 325 residents had to be evacuated by Robinson & Birdsell’s liaison team to a nearby evacuation centre. Working in the live environment within the busy city centre location demanded a dedicated Community Liaison Team to manage all communication during the project, ensuring all aspects in relation to the health and safety of the surrounding residents and the general public were addressed.
The demolition works and blowdown were also featured in a BBC2 documentary series titled ‘Demolition – The Wrecking Crew’. The final episode featured Highcourt Tower. The BBC liaised with members of Robinson & Birdsell’s explosive team over a 6 month period, filming from the very early planning stages of the contract including the community liaison aspect, focusing on the dangers, challenges, and highly specialised expertise necessary for this high risk type of demolition.
Leading upto blowdown day Robinson & Birdsell’s dedicated community liaison team worked closely with local residents, businesses and carried out presentations to local schools on demolition and the importance to Health and Safety, ensuring client satisfaction at all times.
Robinson & Birdsell believe that engaging with people from the beginning, understanding the concerns within the local area is crucial to achieving a successful completed project.
This project is yet another addition to Robinson & Birdsell’s portfolio of expertly and safely managed explosive demolition operations, successfully undertaken over the years where high levels of technical skill and strategic planning have been essential.
The project was completed without any environmental or safety incidents and to the total satisfaction of the client, local community and immediate businesses essential to WRAP and demolition protocol. Robinson & Birdsell recycled 99.7% of the entire buildings and their contents, in line with our recycling targets.
Location: Orchard Park Estate, Hull
Scope: Explosive demolition of high rise dwelling and final site clearance
Client: Hull City Council/ NPS
Demolition and Reinstatement of 6 no. 4 Storey Residential Buildings
Works comprise the asbestos abatement, soft strip and demolition of 6 number, 4 storey blocks of maisonettes constructed in the 1960’s on the East Marsh in Grimsby for Shoreline Housing.
Situated in the centre of a busy residential and commercial environment, Robinson & Birdsell were awarded the works following a competitive tender, based on competency and quality after demonstrating robust methods, policies and procedures.
During the tender stage, our demolition engineers inspected the structures and designed an approach to maintain the integrity of the supporting slender concrete frames whilst removing the majority of prefabricated non structural items and timber floors from within the internal courtyard areas of the site. As the properties were surrounded by busy thoroughfares this resulted in a programme that required less footpath and highway closures during main demolition works resulting in minimal disruption to the local community, and significantly improved waste streams.
Stakeholder management and proactive liaison with the community was integral to the success of our works.
A 98% recycling target was achieved during the works with resultant crushed brick and concrete being used on site to grade and level the area.
The works were completed successfully without any accidents to programme and to the complete satisfaction of our client.
Location: Comber Place, Grimsby
Scope: Asbestos abatement, soft strip, demolition and reinstatement of residential buildings
Client: Shoreline Housing Group