Annual Report,2009 - Directorate General of Mines Safety
Annual Report,2009 - Directorate General of Mines Safety Annual Report,2009 - Directorate General of Mines Safety
DGMS Annual Report, 2009 No. DGMS (Tech)/Circular No./ 14 Dhanbad, Dated – 17.11. 2009 To, All Owner/Agent/Manager of Underground Coal Mines. Sub:- Use and care of Local Methane Detectors in Underground Coal Mines. Of recent, Local Methane Detectors (LMD) are being installed in underground coal mines for monitoring the make of inflammable gases and for imitating suitable mitigating measures well in advance before the concentration assumed dangerous proportions. In this connection, a DGMS (Tech) Circular No. 6 of 2009 was issued to the industry covering a few aspect of the installation and operation of the LMDs in the mines. However, recent inspection of such installation by the officers of this Directorate revealed that such installation are not in a position to deliver the purpose for which they were installed, on account of several reason. It was also revealed that the aforementioned DGMS (Tech) Circular No. 6 of 2009 was also not being followed in the right spirit. This matter was viewed on a serious note and a technical workshop was organized in this Directorate at Dhanbad on the 8 th of September, 2009 for extensive deliberations on the above subject. As a result of the deliberations, the following recommendations were arrived at. 1.0 Various components which make an LMD :- An LMD shall include the following as essential basic components. A CH 4 sensor unit An FLP housing for the electrical circuits and a display unit for the detected and measured CH 4 concentration. The FLP housing may be integrated with the sensor unit. The FLP housing shall be of an approved type. The FLP housing shall accommodate various arrangements for battery backup and coupling the LMD with the power supply system of the ventilating district. An audio-visual warning alarm unit. 2.0 The defined parameters of the life of the sensor used in the LMDs and their operating limits in terms of temperature and relative humidity :- The minimum life of a sensor used in the LMDs shall be at least three years. The sensor shall operate satisfactorily at a temperature upto 50 0 C and a relative humidity of upto 100%. 3.0 Place of installation of the LMD :- The LMD shall be installed in the main district ventilation return airway of the district, as close as practically possible to a well supported roof as may facilitate clear observation of the display unit. 184
DGMS Annual Report, 2009 4.0 The type of electrical interlinking necessary with the LMD :- Every LMD shall have a provision of a suitable outlet for coupling with the electrical supply system of the ventilating district by way of approved cables, connectors and other electrical accessories. The tripping circuit of the LMD shall be electrically interlocked with the power supply system of the connected workings so as to cut off power supply when the concentration of the measured inflammables gases exceeds a preset value. 5.0 The minimum required power back up with the LMD :- The minimum required power backup in the event of disruption of the main electrical power supply shall be for a period of 60 minutes, to be provided by a battery preferably of a rechargeable type and with a minimum life of 12 months from the date of dispatch of the battery. Wherever there is no battery backup, the same shall be incorporated within a period of six months. 6.0 The levels of Audio-visual alarm to be provided in terms of intensity :- The audio level of the audio-visual alarm shall be at least 85 dB (A). The visual alarm shall be consisting of a cluster of LEDs or other suitable arrangements as may be distinctly visible from at least two opposite directions. 7.0 The frequency of calibration of sensors and other components :- The maximum interval of calibration of the sensors shall not exceed three months, alternating between the OEM and the user. All calibrations shall be done by the OEM. 8.0 The type of back-up service required for proper up keep of the system viz-aviz reliability :- The OEM examine the LMD in totally at least once every six months. It is therefore, requested that the above recommendations are implemented in true spirit in respect of all installations of LMD in underground coal mines. Also, you are requested to utilize the mechanism of the Internal Safety organizations (ISO) of your respective companies to have a time bound action plan to ensure that installed LMDs are always maintained functional and in reliable conditions. Ref:Law(HQ)/Legal-Circular/09/01 Dated, the 20 th April, 2009 To, All the Technical Officers, DGMS, Sub:- Production of Gazette Notifications such as Appointment as the Inspector of Mines/ Electrical Inspector and General authorization issued under Sec. 75 of the Mines Act-1952, whichever is applicable. 185
- Page 133 and 134: DGMS Annual Report, 2009 Area and v
- Page 135 and 136: DGMS Annual Report, 2009 Developmen
- Page 137 and 138: DGMS Annual Report, 2009 [No.Board/
- Page 139 and 140: DGMS Annual Report, 2009 Safety rel
- Page 141 and 142: DGMS Annual Report, 2009 ventilatio
- Page 143 and 144: DGMS Annual Report, 2009 Levelling
- Page 145 and 146: DGMS Annual Report, 2009 Longwall m
- Page 147 and 148: DGMS Annual Report, 2009 Mine winde
- Page 149 and 150: DGMS Annual Report, 2009 Miners‟
- Page 151 and 152: DGMS Annual Report, 2009 Reading of
- Page 153 and 154: DGMS Annual Report, 2009 (b) (c) (d
- Page 155 and 156: DGMS Annual Report, 2009 No. DGMS (
- Page 157 and 158: DGMS Annual Report, 2009 It is, the
- Page 159 and 160: DGMS Annual Report, 2009 whereas be
- Page 161 and 162: DGMS Annual Report, 2009 working sp
- Page 163 and 164: DGMS Annual Report, 2009 drivers, a
- Page 165 and 166: DGMS Annual Report, 2009 medically
- Page 167 and 168: DGMS Annual Report, 2009 During the
- Page 169 and 170: DGMS Annual Report, 2009 (a) (b) (c
- Page 171 and 172: DGMS Annual Report, 2009 iv) The St
- Page 173 and 174: DGMS Annual Report, 2009 also cemen
- Page 175 and 176: DGMS Annual Report, 2009 immersion)
- Page 177 and 178: DGMS Annual Report, 2009 No. DGMS (
- Page 179 and 180: DGMS Annual Report, 2009 constituen
- Page 181 and 182: DGMS Annual Report, 2009 work perso
- Page 183: DGMS Annual Report, 2009 (i) (ii) (
- Page 187 and 188: DGMS Annual Report, 2009 DIRECTOR G
- Page 189 and 190: DGMS Annual Report, 2009 strength o
- Page 191 and 192: DGMS Annual Report, 2009 transmissi
- Page 193 and 194: DGMS Annual Report, 2009 Safety in
- Page 195 and 196: DGMS Annual Report, 2009 Flame safe
- Page 197 and 198: DGMS Annual Report, 2009 Correlatio
- Page 199 and 200: DGMS Annual Report, 2009 Photogramm
- Page 201 and 202: DGMS Annual Report, 2009 Haulage an
- Page 203 and 204: DGMS Annual Report, 2009 Rules, 195
- Page 205 and 206: DGMS Annual Report, 2009 rock mass
- Page 207 and 208: DGMS Annual Report, 2009 loaders; b
- Page 209 and 210: DGMS Annual Report, 2009 Notified a
- Page 211 and 212: DGMS Annual Report, 2009 Mine explo
- Page 213 and 214: DGMS Annual Report, 2009 Types of p
- Page 215 and 216: DGMS Annual Report, 2009 extraction
- Page 217 and 218: DGMS Annual Report, 2009 as substit
- Page 219 and 220: DGMS Annual Report, 2009 5 Anchorag
- Page 221 and 222: DGMS Annual Report, 2009 parameters
- Page 223 and 224: DGMS Annual Report, 2009 water redu
DGMS <strong>Annual</strong> <strong>Report</strong>, <strong>2009</strong><br />
4.0 The type <strong>of</strong> electrical interlinking necessary with the LMD :- Every LMD shall<br />
have a provision <strong>of</strong> a suitable outlet for coupling with the electrical supply<br />
system <strong>of</strong> the ventilating district by way <strong>of</strong> approved cables, connectors and<br />
other electrical accessories. The tripping circuit <strong>of</strong> the LMD shall be<br />
electrically interlocked with the power supply system <strong>of</strong> the connected<br />
workings so as to cut <strong>of</strong>f power supply when the concentration <strong>of</strong> the<br />
measured inflammables gases exceeds a preset value.<br />
5.0 The minimum required power back up with the LMD :- The minimum<br />
required power backup in the event <strong>of</strong> disruption <strong>of</strong> the main electrical power<br />
supply shall be for a period <strong>of</strong> 60 minutes, to be provided by a battery<br />
preferably <strong>of</strong> a rechargeable type and with a minimum life <strong>of</strong> 12 months from<br />
the date <strong>of</strong> dispatch <strong>of</strong> the battery. Wherever there is no battery backup, the<br />
same shall be incorporated within a period <strong>of</strong> six months.<br />
6.0 The levels <strong>of</strong> Audio-visual alarm to be provided in terms <strong>of</strong> intensity :- The<br />
audio level <strong>of</strong> the audio-visual alarm shall be at least 85 dB (A). The visual<br />
alarm shall be consisting <strong>of</strong> a cluster <strong>of</strong> LEDs or other suitable arrangements<br />
as may be distinctly visible from at least two opposite directions.<br />
7.0 The frequency <strong>of</strong> calibration <strong>of</strong> sensors and other components :- The<br />
maximum interval <strong>of</strong> calibration <strong>of</strong> the sensors shall not exceed three months,<br />
alternating between the OEM and the user. All calibrations shall be done by<br />
the OEM.<br />
8.0 The type <strong>of</strong> back-up service required for proper up keep <strong>of</strong> the system viz-aviz<br />
reliability :- The OEM examine the LMD in totally at least once every six<br />
months.<br />
It is therefore, requested that the above recommendations are implemented in true<br />
spirit in respect <strong>of</strong> all installations <strong>of</strong> LMD in underground coal mines. Also, you are<br />
requested to utilize the mechanism <strong>of</strong> the Internal <strong>Safety</strong> organizations (ISO) <strong>of</strong> your<br />
respective companies to have a time bound action plan to ensure that installed LMDs<br />
are always maintained functional and in reliable conditions.<br />
Ref:Law(HQ)/Legal-Circular/09/01 Dated, the 20 th April, <strong>2009</strong><br />
To,<br />
All the Technical Officers,<br />
DGMS,<br />
Sub:- Production <strong>of</strong> Gazette Notifications such as Appointment as the Inspector<br />
<strong>of</strong> <strong>Mines</strong>/ Electrical Inspector and <strong>General</strong> authorization issued under<br />
Sec. 75 <strong>of</strong> the <strong>Mines</strong> Act-1952, whichever is applicable.<br />
185
Change language