5th July 2016 Roof Fall GROSVENOR LW 101 Maingate
05.07.2016 Fall MG 101 Face + comments MRE – Grosvenor Coal Mine –
POINTS TO NOTE
Roof Fall occurred at 9:30pm on 4/07/2016 and Inspectors informed at 1:01am 5/07/2016.
07/07/2016 Mine Record Entry Page 12 of 14
This despite being slapped on wrist about delay in MG102 fall. Inspectors called within an
hour
Fall from #8 chock across the maingate and 4 m outbye.
REPORT BACK MG 102. (05/06/2016)
Appears that all bolting equipment was installed and used correctly.
This only leaves an inadequate support plan as the cause of failure.
What has the Management done to address this failed support pattern is not still in
use and what about any remedial/secondary support where necessary.
No mention about Entrapment Equipment on Continuous Miner from 6/6/2016
When will the Inspectors Provide “feedback”?
LW 101
LW retreated 240m still 60m short of square. Still in commissioning problem with base
lift rams.
Uni-directional cutting Maingate to Tailgate. Mainly on auto. Two operators and
trainee.
Wayne Bull (UMM) reports cavity at chocks #3 and #4 beginning “to lip on” and
bagging of mesh just out-bye the face line at the maingate. Assume ‘lip on” is manager
speak for cavity getting bigger
Bull did not consider it significant.
On what basis, he has worked both at North
Goonyella and Moranbah North, he should know better. Same seam, same problems
with gas and roof.
No indication of what time Wayne Bull was at the face the previous day, how much
cutting took pace or a timeline of what occurred and what the cavity and bagging
progressed since Bull was there.
7 Dot Points
1. Change management failure on seam changes for cutting profile
2. Goonyella Middle seam norm
3. Goonyella Middle seam norm
4. Goonyella Middle seam norm
5.Norm except for row of at least 1 extra 8.2 megabolt in the centre of the roadway,
often 2 megabolts
6. Floor heave and floor cracking. Any methane liberated?
7. Of course there should be full analysis.
Nothing about what is to take place before mining restarts except face recovery.
Last paragraph is a Goonyella Middle seam norm for support. Whether pre belt move
well after the roadway is already driven or as part of the normal mining cycle is the
question.
Mine hates cutting stone floor. Loses 20 to 30 tungsten tip bits. Frictional ignition risk
if not changed
Spray system elements for dust suppression discussed. Never seen operational.
Comment about being effective because the face was clean.
It was over 12 hours in between fall and inspectors arriving on site. Besides how much
coal was being cut.
Shearer drum cowls removed. Why? Normally fitted with sprays.
Breaker Stage Loader new covers would have been destroyed if fitted. Obviously not
fit for purpose if they would be destroyed by 1 roof fall.
Dust discussed by Inspectors Dobson and Djukic on 13/06/2016
Methane levels supposedly goes from 0.2% at maingate to 0.5% at the tailgate.
Yet talks about 2 ventilation curtains and 3 venturi’s being used to disperse methane
flushed from the goaf in the last 60 metres along the face.
It only gets to 0.5% general body and that much work with venturi’s etc.
Comments about dust towards the tailgates tells me little cleaning in fact.
Comments about belt slip for excess water. All water sprays and hoses are not
used because that is when the belt slippage problems occur. That is why a dewatering
chute is planned.
Comment about visible vapour etc and oil smells, speaks for itself
MG 102
Surprise, surprise, what was geological structures in B heading ended up in C heading
and that was why they could not hold the roof eventually in B heading. Who would
have thought that?
CLOSE OUT MEETING
DNRME lays no Directives of any description, just they will Review and provide
feedback
“Also what the future strategy should be in support installed in development and
secondary support phases.
Dust Mitigation
Subject to Direction from Dobson and Djukic from the 13/06/16 MRE
Get back to Grosvenor once read ICAM report MG102 fall.
