Working for Private developer Grove Developments, Carney completed the civil infrastructure and enabling works for the new Hilton hotel development at Heathrow Airport Terminal 2. The initial scope was to install a foul retention channel and manage sub-contract packages of directional drilling under Highways Agency (HA) asset the A30 into Heathrow Airport Ltd. (HAL).
- Start date: October 2017
- Completion date: August 2018
- Form of contract NEC: Option C
- Total value: £1.5million+
Under a NEC contract Carney Construction acted as the principal contractor setting up the management systems, notifying the HSE, and securing the site, this was a complex project due to the managing of key stakeholder’s infrastructure. This included HV cables under the A61, Fibre optics running HAL Security, working near the secure line for the airport and border force. The scope increased to installing power lines and additional drainage around a control point (Heathrow secure access), fixed hoarding and connections for another hotel in the vicinity.
1. Safety & Environment
During the development of the scheme Carneys proposed to use directional drilling to avoid the Highways Agency infrastructure and avoid large tunnel construction, this was presented to highways England who were satisfied the controls were in place with a detailed CPP showing that the risk to assets was negligible and the road could be maintained as operational throughout the works.
Directional drilling was completed and worked within tolerances, we then utilised Carney plant department to use vacuum excavators to complete safe digging around HAL buried services and infrastructure due to the volume of unknown services. As-built records and redline drawings were completed and issued to allow future contractors to navigate around the new and existing services in the area.
The works were situated near to local residence and onsite vibration monitoring was completed as per network rail standards to ensure that vibration limits did not exceed the current background levels caused by airport traffic despite concerns from key stakeholders this may be the case for localised sheet pile installation.
For this scheme by the time Carney were appointed to complete the works the precast manufacturer was not able to meet the client start dates. Our team reviewed the option of using pre-cast channel sections and through collaboration with the client design team we were able to improve the
programme by reverting to an in-situ development of the channel. Carney were still able to complete
the site works in the same construction duration onsite as programmed for installing the precast.
This would also prevent concerns raised that the precast connection details may not provide a
suitable seal from leaking of hazardous materials into the ground water.
Throughout the works carney used the approved Carney ISO quality procedures for managing signoff
and sectional completions to allow integration of assets into the HAL asset base.
Carney Construction managed to meet the precast construction rate through using a system of steel shutters with turfers able to be controlled by hand onsite without the need for expensive plant to move heavy pre-cast sections. This also provided less disruption of transport for the local area and reduced vibration onsite.
Carney mobilised its team in a shift pattern compatible with the busy/quiet periods of the airport, this ensured that productivity could be maintained without disrupting passengers to the main terminal and permitted involved traffic management to block roads on this highly constrained site.
Conclusion & Summary
Carney have been praised for their flexibility and adaptability on a challenging site with difficult
stakeholder liaisons and have proven a collaborative approach to both design change and changes to
method of working. This has helped Grove to deliver this project to the programme and cost
requirements despite frequent scope changes:
- Working as Principal contractor on end scheme value of £1.52 million package of enabling, hard landscape and civils packages around multiple large stakeholders on a constrained site.
- Adaptable method of construction & direct design management to simplify, speed up and reduce cost while increasing the quality of the final product.
- Vibration monitoring and significant stakeholder engagement completed.
- Specialist plant able to provide peace of mind when working around critical airport services within confined site areas.
- Co-ordinating site operations around airport security operations and other contractors meeting all access date requirements
- Scope increased to provide micro-piling, installation of link bridge, hoarding, utility installations and hard landscaping packages including stakeholder management.