Longwalls are getting faster, longer, and deeper.
Both longer and deeper longwalls are faced with large increases in ground pressure. Engineers counter this with larger cylinder diameters, and higher hydraulic pressures.
Production demands that the cutting machines (shearers or ploughs) get faster, shield cycle times get shorter, and more shields must move simultaneously.
Longwalls get more capital intensive, faster and, over time there become fewer for a given coal production target.
Pump stations, therefore have to deliver higher pressure, higher flow and be more reliable.
For the most productive longwalls, the rate at which shields can be moved, and the conveyor advanced, are on the critical path to high production. Both of these are strongly dependent on the pump station's performance.