Traylor (Bentonite Plant)



Traylor Frontier-Kemper
Sound Transit University Rail Link (U220 Contract)
Seattle, WA, USA

10 m3/hr Hydrated Bentonite



  • Conceptual Design
  • Structural/Mechanical Engineering
  • Fabrication of all Equipment
  • Modification of Existing PLC/HMI
  • On-Site Training & Site-Support


  • 52m3 Bentonite Hydration Tank With Agitation System
  • Screw Conveyors
  • Diaphragm Pumps
  • Mk IV Colloidal Mill Upgrade
  • New PLC/HMI Programming
  • Refurbishment of Existing Plants
  • Insulation and Heat Pads for Admix and Accelerator Tanks
  • UL Listing

As part of the 3.15 mile extension to Seattle’s light rail commuter line, the Traylor Frontier-Kemper joint venture was awarded the U220 contract from the University of Washington to the Capital Hill station. Two 21 ft. diameter Herrenknecht EPB machines were used to drive the twin 11,300 ft long tunnels.

Team Mixing Technologies previously supplied a pair of Bi-Component grout plants to Traylor Brothers for the San Vicente project. These plants were reconfigured and combined to form a new plant for the twin TBM’s which launched from the Husky Stadium parking lot.

A bentonite hydration tank was also designed and fabricated for this project. Hydrated bentonite is pumped from this tank to the colloidal mixers and is used to prepare the “A” component grout. The use of hydrated bentonite (as opposed to adding dry bentonite powder) results in a more stable grout with reduced bleed. The two plant colloidal mixers are used to batch the hydrated bentonite when not in use preparing grout.

The plants PLC control systems and HMI touchscreens were reprogrammed for this new configuration. Both plants were also refurbished and upgraded with the new MkIV mechanical seals on the colloidal mills.