Background

BAM Nuttall was appointed to deliver drainage and highway works on the M3 between Junctions 3 and 4, including the construction of an additional northbound diverge lane at Junction 3.

During construction, design changes and revised ground conditions required the drainage layout to be realigned, extending the programme into late 2009.

The challenge

Key challenges included:

  • Introducing flow control after drainage had already been installed
  • Avoiding re construction of on line chambers
  • Maintaining programme flexibility during a live highway scheme

The solution

Marshalls supplied Hydro Brake® flow control chambers, which were successfully retro fitted onto previously laid drainage infrastructure using band seal connections.

This demonstrated that the chambers:

  • Did not need to be installed on line
  • Could be programmed later in the construction sequence
  • Allowed drainage works to continue without waiting for chamber delivery

The outcome

  • Programme flexibility maintained despite design changes
  • No requirement to reconstruct drainage runs
  • Demonstrated adaptability of Hydro Brake® chambers on live highway schemes

Contractor feedback highlighted the value of being able to decouple chamber installation from initial drainage construction.