TableĀ 3.

Lowering of the shield and reduction in shield loading caused by yielding when support is operated at a particular height

Shield typeYield pressure (MPa)Min. operating height (m)Operating height (m)Extension of hydraulic liquid1 (m)Compression of shield due to yielding (mm)Reduction in support loading caused by yielding (t)Compression of shield per 100 t of applied load (mm)
ZY10800/28/63D43.02.85.83.06.45108.45.95
ZY15000/33/7238.23.36.33.05.73150.13.82
ZY18800/32.5/72D47.93.256.83.558.50188.74.50
ZY26000/40/88D46.04.08.54.510.35259.83.98
  • 1Extension of hydraulic liquid is calculated as the current operating height minus the minimum operating height.