BT Lift & Shift Project

Ringway was due to redevelop Water Gardens South carpark in Hemel Hempstead for the local council. A new access road was being installed from Leighton Buzzard Road into the carpark to reduce traffic build up.
The area was cleared of trees ready for the new road and Ringway carried out several trial holes to confirm the location of the existing BT ducts. A block of 18 clay ducts were uncovered with only 400mm of cover to the top ducts. Due to the new road location these ducts needed to have 1.3m of cover to ensure they were below the makeup of the road. BT were unable to lower the ducts for 10 months and the cost was over £1 million.
THB was asked if they could lower 70m of the ducts for Ringway due to the company’s experience in Telecoms. BT agreed to provide supervision as required.

The existing ducts were marked out by THB’s cable tracer and a trench was excavated either side. The top of the ducts where then exposed and timbers installed over the top. Ratchet straps were then used to support the bundle of ducts before the remaining ground was excavated from beneath the ducts using a Vacuum Excavator.

Shrink wrap was used around the collars on the ducts to hold them together. Chain blocks were then added to lower the ducts to the required depth. Trench support was removed and the trench was reinstated ready for the new footpath and road construction to commence.