Pump chamber installation & new tarmac layer

Location: Kidbrooke, London SE3. Case Study

Work carried out for Elliot Environmental Drainage – August 2022

Background: Pump chamber installation.

Works were for the Thomas Tallis school. The existing pump chamber rings had failed over time and were leaking water into the chamber, works to remove the existing tarmac at approximately 25sqm, then remove concrete biscuit to access concrete Milton rings.

Plans to supply new concrete Milton rings which are smaller than existing, to create an internal sleeve, for the pump chamber, C30 concrete to be poured in the gap between Milton rings which is approximately 300/600mm throughout, reinforcing bars to be used where required on backfill.

Existing Milton rings are 2.74m internal x 1m long x 5 quantity to be sleeved with new Milton rings which are 2.1m internal x 1m long x 5 quantity, for the Pump chamber installation.

Once works have been completed on the Milton rings we would reinstate the existing concrete biscuit and manhole cover then lay the tarmac to the required depths. Bike hoops are to be installed back into the tarmac as previously installed.

All pump gear/electrics and rails had to be removed prior to works, then placed back once new Milton rings have been installed.

Works to include

Cat scan/ Site set up/ Installation of heras panels and warning signs.
Removal of the pump and electric equipment, to be stored on site.
Removal and disposal of existing tarmac approximately 25sqm.
Bike hoops are to be removed and stored until tarmac reinstatement.
Removal of existing concrete biscuit for Milton ring access.
Supply and installation of 2.1m internal x 1m long concrete Milton ring x5 number, which will be used to internally sleeve existing rings.
Pour C30 concrete around the space between rings, approximately 300/600mm in diameter.
Reinstate concrete biscuit.
Installation of the pump and electrical equipment.
Re lay 60mm of 20mm DBM Base.
Re lay 30mm of 10mm DBM Top.
Reinstate bike hoops.
Hire a 13ton digger and a 3ton dumper with delivery/collection.