Dragados-Sisk Pudding Mill (TBM Grout Plant)



Dragados-Sisk Joint Venture
Crossrail Project – Contract C305
London, England

12 m3/hr



  • Conceptual Design
  • Mechanical Engineering
  • Fabrication of all Equipment
  • Commissioning
  • On-Site Training and Site Support


  • Tornado 1200 Colloidal Mixer
  • 40’ Heated Container
  • 3000 litre Agitation Tank
  • 20 m3 Bentonite Hydration Tank
  • 108 m3 Capacity Cement Silo
  • 55 m3 Capacity Flyash Silo
  • 27 m3 Capacity Bentonite Silo
  • Three Screw Conveyors
  • One 55 m3 Heated Accelerator Tank
  • Automated PLC/MCC Control System
  • Air Compressor & Pneumatic System
  • Admix System
  • 65mm Peristaltic Grout Pump

Dragados-Sisk JV was awarded the Crossrail C305 contract which comprises three of the five twin tunnel drives on the project. Two of the drives originate from the Limmo Peninsula whereas the twin 2.7 km drives (Drive Z) will proceed from Pudding Mill Lane to Stepney Green.

For the Pudding Mill lane site Team Mixing Technologies Inc. designed and constructed a combined bi-component (A/B type) grout plant and hydrated bentonite plant housed within a 40’ shipping container.

A Tornado 1200 colloidal mixer prepares both grout and hydrated bentonite. The hydrated bentonite is stored in a 20 m3 capacity agitated tank. This hydrated bentonite is then used to prepare the “A” component grout. Then grout is held in a 3 m3 agitation tank until called by the TBM. A 25 bar rated peristaltic pump transfers the grout from the plant to the TBM holding tank.

Team Mixing also provided an insulated/heated sodium silicate (accelerator) holding tank. Accelerator is taken to the TBM via rail cars.