About the Project
The enabling works comprised of four sections which had to run concurrently to meet the programme required by the client for the land sale.
Site Access – Section 278 Scheme:
A roundabout had to be constructed offline of the existing highway which formed the site entrance to the Harworth Development and the Davidson’s site on the opposite side of Grange Road. The works involved constructing the roundabout in four phases under 2-way temp traffic lights to maintain access for local road users.
Works comprised of
- Highway drainage in existing carriageway and 250m onsite outfall to attenuation basin
- Carriageway Construction
- Footway Construction
- Utility Installation
- Street Lighting, signage, and white lining
As part of the works we had to liaise with Severn Trent Water who were installing a 400mm diameter water main and GTC who were installing medium pressure gas pipework and HV cables.
70,000m3 of topsoil was stripped from the site with most been stored in a stockpile for future use on the far side of the River Sense. A temporary bailey bridge was erected to gain access and was present throughout the scheme.
A 3D earthworks model was used to form the future plateaus for the housing schemes and a total of 5 attenuation basins. A total of approximately 82,000m3 of sub soil was used in the cut/fill process carried out to RSK specification to satisfy HNBC. Where necessary lime stabilisation had to be utilised to meet the specification.
Associated Pond Drainage & Headwalls:
Varying sized storm drainage and structures were installed around the attenuation ponds this included the following
- 1080m of Pipework
- Three outfalls into the adjacent River with pre-cast concrete headwalls
- control chambers
- concrete bag work headwalls
The site was originally a working farm – a total of 14 different structures had to be demolished to allow the earthworks to proceed. Asbestos was identified in or on several of the structures – this was removed from site as part of the works.
- Historical earthworks were present onsite this area had to be fenced off to prevent any plant movement over the area. Specific RAMS had to be approved to allow plant access for the two storm outfall sewers within this area into the river from the attenuation basins.
- Overhead 33kva cables – plans were put in place for working near to and under the cables which were fully compliant with GS6 guidelines. Fortunately, WPD were able to divert and take down the overhead lines prior to the start of the contract.
- Land sale date of 1st June 2020 – the two parcels had to be handed over with the earthworks complete and the roundabout operational. This was achieved even through a challenging weather period where it seemed to constantly rain from Sept 2019 to Feb 2020.
We were asked by the client to act as Principal Contractor for the works.
As the contract progressed, we were awarded the package for installing the onsite spine roads, drainage, utility installations and footway construction.