Thrust Reducer

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

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

Steering Shield for Sharp Curve 

Extra Jacks are installed in streering shield behind of main shield to create more flexibility for steering device so that sharp curve pipe jacking works can be achieved.

Data & Facts
Machin type:DT-3000
Curve:R80
Location:TokyoJapan