The most commonly used shoring and lining system in unstable soil conditions, for its strength & maniabilty.
The double slide rails are maintained parallel thanks to the stiff rectangular frame. It can slide vertically during the dig & cut method. When the bottom of the trench has been excavated, the slide frame can be lifted in order to ensure a good high clearance. The individual action exerted on each element separately facilitates the installation and deposits, reducing the frictional forces of the ground.
It can be used for the large dephts and widths