Prep Seal Installation 7Nth Longwall Panel North Goonyella MRE 14th January 2014. Decision to install Prep Seals made which were used 3 weeks later to seal 7Nth and bring heating under control

140203 An event causing the withdrawal of a person from the mine or part of the mine

The 7Nth Longwall Panel and Remaining Longwall Equipment were sealed using Preparatory Seals on the 3rd of February 2014.

This was in response to the triggering of the L4 Spontaneous Combustion PHMP Response Withdrawal of Workers.

At approximately 16:50 on 3/2/2014 analysis of a bag sample at 7North TG preparatory seal site taken from underground led to a Level 4 Tarp triggering the orderly withdrawal of persons from the mine. As part of the withdrawal of person from the mine the MG and TG preparatory seal sites were closed sealing the 7North Longwall panel.

The installed Prep Seals were closed as part of the final  actions of the orderly withdrawal process.

The reason there were Prep Seals in place is that it was decided to construct the Prep Seals on the 14th of January 2014 at an IMT meeting that Deputy Chief Inspector Russell Albury attended

Prep seals are under construction in both MG and TG 7 Nth in the off chance that the situation develops into a serious heating event.

Coincidentally Inspector Albury had attended the Mine with Principle Investigation Officer, Mr Andrew Broadfoot  to determine the progress of the mine in treating, identifying and planning to manage the elevated CO readings in TG 7 Nth.

Discussions were held pertaining to the issue. North Goonyella Mine Management did not know the cause of the elevated CO readings at that stage.

Marek Romanski who was the Underground Mine Manager in 2018 was part of the IMT in 2014.

Romanski is well aware that Prep Seal Installation was part of preparing for an out of control spontaneous combustion event in 7 Nth.

Romanski would also be well aware being able to use Prep Seals brought the heating in 7 Nth under control

Again why have Romanski, the rest of the Mine Management and the Mines Inspectors not installed Prep Seals in 2018?

 

140114 7N Prep Seals Ethylene Albury DME MRE

A site meeting was conducted today, 14/01/14, at the North Goonyella coal mine by Deputy Chief Inspector Mr Russell Albury and Principle Investigation Officer, Mr Andrew Broadfoot. We arrived at the mine site at 10:40am and were greeted by the UMM Mr Michael Lerch. The mine was in the process of finalising their daily spontaneous combustion review meeting in relation to 7 Nth and the Inspectors were invited to join the meeting.

At the meeting were M. Lerch (UMM), L. Marnane, G. McGetrick, D. Craft, N. McAlary and M. Romanski was participating via speaker phone from Brisbane.

The reason for the visit was to determine the progress of the mine in treating, identifying and planning to manage the elevated CO readings in TG 7 Nth. Discussions were held pertaining to the issue and covered the following points; the mine does not know the cause of the elevated CO readings at this stage.

The Ethylene of 1.7ppm detected in the TG goaf stream appears to be “noise” in the Gas Chromatograph. The mine is not confident in the GC ability to accurately read Ethylene at levels below 5ppm. The mine has sent samples to Moranbah North for verification. The Moranbah North GC detected similar quantities of Ethylene in the sample.

I mentioned that the mine should consult SIMTARS and especially Martin Watkinson for help as I am aware that Moranbah North had trouble last year with a new GC picking up around 2ppm of Ethylene. Martin may be able to provide some answers.

Prep seals are under construction in both MG and TG 7 Nth in the off chance that the situation develops into a serious heating event.

A decision has been made to seal the LW if 3.5ppm of Ethylene is detected. This is contrary to the 5ppm trigger point in the mine TARP.

I asked the mine if they had reviewed the situation which had occurred in 3/4 Nth. My understanding is that it was a similar situation and similar mine lay out i.e 2 x LW’s side by side. The mine said they had not and had difficulty in finding any information because of Insurance issues and confidentiality. I suggested the mine talk to Martin Watkinson and Darren Brady who were both involved at the time of this previous event.

I suggested that the mine prepare a process for taking gas bag samples from boreholes and ensure there are boreholes and sites available should the SIMTARS mobile lab be required and the mine is evacuated. This is a precautionary process in the event that an evacuation occurs and gas data from underground has to be gained from the surface.

The mine indicated that there is a swilly or water accumulation in TG 8 Nth which they are having trouble controlling. This would increase the pressure differential between TG 8 nth and the goaf of 7 Nth.

The mine is today taking a pressure survey of all the seals in TG 8 Nth to quantify the problem.

The mine continues to run the floxal inertisation unit and is presently injecting at both 7 and 8 c/t in MG 7 Nth. The CO readings are presently trending down.

The mine appears to have mitigating measures in place and a plan to protect the safety and health of people if the situation deteriorates. The CO appears to be trending down and steps are under way to locate the cause of the elevated CO and presence of the Ethylene.