Project Overview


Highways England

Construction Period

26 Months


£20-25m range

Project Overview

Subcontract for the early earthworks/drainage works in seven separate areas of the A30 Chiverton to Carland Cross Dualling project in Cornwall.

Works include (but not limited to) installation of carrier or filter drains, attenuation pipes, catchpits and associated foundations, manholes/chambers, headwalls, surface water channel inlets/outlets, rodding eyes including points and covers, all connections including but not limited to vertical risers,
inclined risers, and backdrop connections.

In due course also movement and placement of excavated material up to 750m from point of excavation, distribution of all materials from the contractors primary and secondary compounds.

All temporary works submitted and approved prior commencement of works.

Key Numbers

  • Extensive site clearance
  • 3000m carrier drain
  • 2800m filter drain
  • 97x catchpits
  • 132x manholes
  • 9x headwalls
  • 4x attenuation ponds
  • 1x attenuation tank – 1290m3 capacity
  • Pre-earthworks drainage and water quality management
  • Topsoil strip – 500,000m3
  • Cut & Fill – 1,300,000m3
  • U1a excavation and on site disposal – 350,000m3
  • Excavation in hard material – 200,000m3
  • Topsoil placement – 350,000m3
  • Construction of temporary embankments – 80,000m3
  • Placement of initial sub-base layer – 150,000m3
  • Pond excavation & lining – 20 ponds, 200,000m3 capacity
  • Box culvert construction (DC11)