Attenuation Tanks

Skanska is preparing to deliver the A428 Black Cat to Caxton Gibbet Improvement Scheme on behalf of National Highway. This package is for supplying Attenuation Tanks as follows;

Attenuation systems shall be supplied, installed and backfilled by the supplier as per the details provided in the construction drawings. Supplier shall provide warranties as per industry standards. These shall be BBA certified and conform to the CIRIA guidelines. These shall be leak proof and vented to dissipate air pressure.

The system shall be able to take the highway loadings demonstrated by the calculations. The system shall be supplied with the manifolds and required accessories to connect to the upstream and downstream drainage chambers. Any geotextile wraps or surround shall be part of the installation. The storage tank shall be impermeably lined with an impermeable membrane and constructed as per the manufacturer's instructions.

Flow control shall be installed in the downstream chamber of the storage tank to attenuate the flow to the agreed rates. Flow shall be controlled by means of an orifice plate or similar as specified in drawings and drainage schedules.

The supplier/Installer will have to install the upstream and downstream chamber and connect the system into these chambers. If there are bespoke modules to be used as inspection chambers these shall be incorporated into the system.

Before installation of the system approvals from the client is mandatory for the products, accessories and geotextiles. A data sheet showing allowable loadings and flow rates, storage capacity and other relevant parameters shall be supplied as part of material approval process.

If required precast concrete rings to form upstream and down stream chambers can be supplied to site but the connection of the system shall be down to the supplier.

Before backfilling the units shall be jointly inspected and any testing required shall be carried out.

Water or for testing if required shall be supplied by the installer.

Material for backfill will be supplied on site and rate of supply per day to be agreed.

Site shall be cleared of all debris and remaining materials by the installer.

You will then be invited to complete our Request for Information (RFI), conducted on our Oracle Cloud platform. The RFI identifies if your business meets the required high standards expected in the Highways sector. The RFI will only take between 10 & 15 minutes to complete, at the end of the process you will be told if you have been shortlisted. If you have you will be invited to respond to the full Request for Quotation (RFQ), which will be issued shortly after the RFI closes.

Please see attached the link with a project overview - https://nationalhighways.co.uk/our-roads/a428-black-cat-to-caxton-gibbet/

To respond to our expression of interest request, please see this link which will take you to a Microsoft form - https://forms.office.com/r/nTQdtVFTiH