High Altitude Diving

Intake Valve Removal and Tunnel Dimensioning

High Altitude Diving – Intake Valve Removal and Tunnel Dimensioning

Customer: Denver Water

 At 6,842ft (2085m) elevation and 221ft (67m) in height, it was the world’s tallest dam when completed in in 1905.  Cheesman Dam supports a key reservoir for Denver Water the provider of potable water to Denver, CO and the surrounding communities.

Upgrades to the site required Ballard Marine Construction to mobilized mixed gas diving gear, multiple hyperbaric chambers, barges, multiple cranes and other equipment to the high altitude, remotely located Dillon Reservoir.

Highlighted Activities included:

  • Underwater demolition of a domed trashrack
  • Remove and salvage a 115 year old intake valve (35,000lb or 15,875kg ) for placement in a museum
  • Performing underwater steel cutting and concrete and rock removal (hydraulic breaking and 40,000 psi high pressure water blasting & abrasive injection system)
  • Remote Operated Vehicle (ROV) assisted hydrographic surveys
  • Internal ROV inspection of the intake tunnel system with sonar dimensioning,
  • Three dimensional imaging of the tunnel systems
  • ROV inspection of trashracks
  • All of this work was completed in depth of up to 180ft (55m) at 7000ft (2134m) or  of altitude.

Issue: The existing concrete was much harder than anticipated and the traditional method of removal was not satisfactory.
Resolution: Ballard Marine Construction mobilized a 40000 psi hp water /abrasive injection system for use by the diver to demo rock and concrete.
This is a perfect example of utilizing traditional