Selection Criteria

Cutters

DH Machine

DH-FS Machine

DH-L Machine

DH-U Curved Machine

DT Machine

BM EPB Segmental 

Slurry Pumps

Guidance Systems

Jacking Systems

Rasa Island

Thrust Reducer

Jacking Layout

Treatment Systems

Beachwalk Project

Microtunneling, Inc. are exclusive agents in North and South America for Rasa 

MTBM, TBM, EPB, Slurry Shields, and Segment Shields.

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Thrust Reducer

 

The Thrust Reducer is designed to achieve long distance jacking of up to 1000 meters. The system is comprised of a Top Reducer, which is attached to the back of the shield machine for the purpose of reducing skin friction force. Other components include the Sub-Reducers (additional reducers at various intermediate locations) for the purpose of further reducing skin friction force during jacking operations. Also included are an auto-flow meter, control panel, and a pump and mixing plant for grouting.

The principle of this system is to mix surrounding ground (approximately 2 to 3 cm) in the grouting mix pan while at the same time lubricants (e.g. RASA BIOS™) are being injected automatically in relation to the jacking speed. The amount can be reduced by about 1/3 to 1/2 as compared to conventional intermediate jacking systems.

Steering Shield for Sharp Curves

Extra jacks are installed in the steering shield behind the main shield to create more flexibility for the steering device so that sharp curve pipejacking works can be achieved.

Data and Facts
Machine Type: DT-3000
Curve: R80
Location: Tokyo Japan