Power on Shearer until 400m Methane Sensor Registers 5% 9th May 2018
I have been trying to understand this part of the Mine Record Entry about not tripping power until the 400m sensor reads 5% (which is the Lower Explosive Limit) and stopping “haulage” production when the Shearer is in the Tailgate Shuffle Zone and the 400m Sensor reads 2% plus and leaving power onto shearer and cutting drums.
The logic involved to have such Regulation Written, Interpreted and Applied escapes me.
Wait till detecting 5% to drop power.
We made the following points in conclusion;-
2. The Mine should reconsider its logic in regard to not tripping power to the shearer until 5% methane is reached and only to stop hauling at 2.0% when the shearer is between 130 shield and the TG leaving power to the cutter drums. Why wait until the methane reaches 2.5% (and hence has the resulting HPI) before tripping power to the shearer? The standard for all other Methane monitors is to trip power at 2.0% or less. Is allowing the TG monitor to reach 2.5% before power is tripped achieving an acceptable level of risk? This point was raised in the MRE issued following the meeting held on 19 Mar 2018. Mr Kirsten undertook to provide feedback on this by Friday 18 May 2018.
3. The Mine needs to review the General Body Contaminants TARP to ensure that the TARP lines up with instructions given to CMW’s on operating the Longwall in a gassy environment. Automated trips, haulage restrictions and other controls should be utilised wherever possible rather than relying on “behaviours” or interpretations by operators and ERZ Controllers.
