Minerals Industry Safety and Health Centre
The University of Queensland
Trigger Action Response Plans in
Underground Coal Mines
Tips, Tricks and Pitfalls
David Cliff
Minerals Industry Safety and Health
Centre
Minerals Industry Safety and Health Centre
The University of Queensland
Typical TARP
 Level 1  Level 2  Level 3  Level 4 -
Normal
Abnormal – tell Mgt
really abnormal – tell Mgt
Oops ! - Evacuate
Minerals Industry Safety and Health Centre
The University of Queensland
Fundamental principles
 Simple and Robust
 Adequately resourced – personnel and
equipment
 Focus on prevention and early detection validation, clarification and remediation
 Requires detailed knowledge of normality
 Triggers not set in stone should be reviewed and
revised as experience grows or conditions
change
 High quality mine monitoring information
 Do not be afraid to ask for advice
 If the TARP mandates an action it must be
carried out promptly
Minerals Industry Safety and Health Centre
The University of Queensland
Minerals Industry Safety and Health Centre
The University of Queensland
Establish range of normal values
Establish normal time dependence of
concentrations and other indicators
Different norms for different
circumstances and environments eg CO
make vs retreat rate or face ventilation Q
Minerals Industry Safety and Health Centre
The University of Queensland
CO Make vs face advance
Minerals Industry Safety and Health Centre
The University of Queensland
Moura
512 vs 401-402
200
150
100
50
0
0
5
10
15
Tim e since se aling (h rs)
512
401 -402
20
25
Minerals Industry Safety and Health Centre
The University of Queensland
Advisory Level
Action by ventilation officer and technical
services personnel + inspections
Validation of readings
Extension of monitoring to other locations,
increase frequency and complexity
Inspection of area for leakage and other
abnormality
Prepare for inertisation or other control action
eg fly ash injection
Seek external advice as necessary
Monitor rate of change with time
Minerals Industry Safety and Health Centre
The University of Queensland
Recent episodes have been catalysed
by the prolonged presence of oxygen in
goaf areas where normally it would not
be were it not for mining problems.
Minerals Industry Safety and Health Centre
The University of Queensland
Alert level
 Advise mine management of potential for
evacuation
 Initiate control measures such as inertisation
 Prepare for evacuation
No unnecessary work underground
Prepare for quick sealing of area of concern
People to stay in close contact with surface
 Monitoring frequency adjusted to rate of
change of atmosphere.
 Monitoring analysis needs to allow for any
control measure effects – gas displacement or
dilution
Minerals Industry Safety and Health Centre
The University of Queensland
Evacuation level
 Orderly evacuation
 Key criteria is the potential for harm to the
workforce
 Timed to allow protection of equipment,
maintenance pumps etc
 Emergency sealing carried out if necessary
Minerals Industry Safety and Health Centre
The University of Queensland
Re-entry criteria
 Conditions established objectively prior to
incident – eg by risk assessment
 May be modified based upon risk assessment
 Criteria for limited re-entry may be different to
those for return of work-force underground.
 Inertisation and other controls may mask
behaviour without necessarily controlling the
incident.
Minerals Industry Safety and Health Centre
The University of Queensland
TARP actions
 For all mandatory actions within TARPS there
must be close out by a specified time.
 Actions should not be just :
Tell VO of gas concentrations – no other action
required by VO
Mine Manager notified- no other action required
 Need audit of actions
 Proper record keeping
Minerals Industry Safety and Health Centre
The University of Queensland
TARP criteria
 Values not set in stone – should be regularly
reviewed
Minimum at end of each longwall block or
extraction area.
If situation stabilises without getting worse
consider revising advisory/alert TARPs.
Avoid glib explanations and production driven
demand to change TARPs.
Changes to TARPS should be documented and
justified.
Changes may be up as well as down.
Minerals Industry Safety and Health Centre
The University of Queensland
TARP criteria
 Basis for action should be severity of incident
 First level trigger is abnormality – significantly
above background level
 Second level trigger is significant and
worsening abnormality – not necessarily twice
background level
 Third level trigger is where there is real risk to
personnel underground – not necessarily
three times background level
 Triggers vary from location to location and
over time
Minerals Industry Safety and Health Centre
The University of Queensland
Panel returns
•Large air flow quantity
•Close to fresh air
•Unreliable deficiency ratios
• Absolute concentrations low and
air flow dependant
•Only reliable indicator – CO make
Minerals Industry Safety and Health Centre
The University of Queensland
Physical Indicators
May be more sensitive than gas
measurement to identify
abnormality and locate emission
points.
Must be supported by gas
measurement
Change from normal is the
detection criterion
Minerals Industry Safety and Health Centre
The University of Queensland
Areas of low or no airflow
 Need norms to compare
concentrations/indicators with.
 Can use concentrations and ratios
within limits of accuracy
 Do not use text book triggers or
norms established under different
mining conditions or locations eg
MG vs TG.
LW101 Goaf Tube Bundle Sample Point Gas Trend
Tube 18 - 49 c/t MG Seal
180.0
(%)
and Health Centre
Safety
Minerals Industry Oxygen
The University of Queensland
25.0
160.0
20.0
120.0
15.0
100.0
80.0
10.0
60.0
40.0
5.0
0.0
12-Feb-99
20.0
04-Mar-99
24-Mar-99
13-Apr-99
O2
03-May-99
CO
CO2
23-May-99
12-Jun-99
0.0
02-Jul-99
Carbon Monoxide (ppm)
Carbon Dioxide (x10-2 %)
140.0
Minerals Industry Safety and Health Centre
The University of Queensland
Indicators in areas of no air flow
Most ratios are measures of the
conversion efficiency of oxygen
to products of oxidation and
are therefore essentially
equivalent.
Minerals Industry Safety and Health Centre
The University of Queensland
Ratios
Therefore no need to use a
multitude of deficiency ratios
as they should all tell the
same story.
Other ratios can be used to
assist investigation not part
of formal plan.
Minerals Industry Safety and Health Centre
The University of Queensland
Site specific indicators
These are ratios or formulae
involving various gas
concentrations that have been
shown to be a sensitive
indicator of deviations from
normal. E.g. H2 to CO ratio or
CH4 to CO2.
TARP review data
100
Minerals Industry Safety and Health Centre
The University of Queensland
95
LEVEL 3
90
LEVEL 2
85
LEVEL 2a
80
75
70
65
H2 ppm
60
55
GR < 0.5
GR> 0.5
GR > 0.7
50
45
40
35
30
25
20
15
10
5
0
0
100
200
300
CO ppm
400
500
600
Minerals Industry Safety and Health Centre
The University of Queensland
Quantify TARPS
 Do not use adjectives or verbs to describe
TARP
“presence” or “trace” of ethylene
“significant” concentration of hydrogen
“abnormal” Graham’s ratio
 Use numbers eg
>10 ppm ethylene
> 50 ppm hydrogen
> 0.8 Graham’s ratio
Minerals Industry Safety and Health Centre
The University of Queensland
Know your indicators
Minerals Industry Safety and Health Centre
The University of Queensland
Fundamental principles
 Simple and Robust
 Adequately resourced – personnel and equipment
 Focus on prevention and early detection - validation,
clarification and remediation
 Requires detailed knowledge of normality
 Triggers not set in stone should be reviewed and
revised as experience grows or conditions change
 High quality mine monitoring information
 Do not be afraid to ask for advice
 If the TARP mandates an action it must be carried
out promptly