This report summarises the fall of ground dangerous
occurrences and major injury accidents reported at mines during
the 1999/2000 reporting year.
2. All statistics are provisional.
3. Any fall of ground not being part of the normal operations
at a mine, which results from a failure of an underground
support system and prevents persons from travelling through the
area affected by the fall of ground or which otherwise exposes
them to danger, was introduced as a dangerous occurrence at
Part II/40 in RIDDOR 1995, with effect from April 1996. This is
the fourth full year that such incidents have been reported to
HM Inspectorate of Mines.
4. Four falls of ground were reported at mines during the year,
all at coal mines.
5. One of the falls occurred in a place being salvaged, with
three occurring in places that had been excavated between two
and three years previously.
6. One of the incidents occurred at the gate end of a longwall face end being salvaged, supported by steel girders, supplemented with rockbolts and skeleton road chocks. The other three incidents occurred in places supported by free standing supports with two major falls at junction areas.
|Type of Support|
|Passive + Rockbolts + Wood Chocks||1|
|Warning of Collapse|
|Less than 24 hours||2|
|Over 24 hours||-|
|Age of Excavation|
|6 - 12 months||-|
|2 to 3 years||3|
|Type of Excavation|
|Junction - rockbolts/girders/chocks||1|
|Junction -natural support||-|
|Roadway - props and bars||-|
|Roadway - arches||1|
|Roadway - rockbolts||-|
8. There were no fatal accidents but eleven major injuries were reported at coal mines compared with three fatal and twenty three major injuries in the previous year.
9. There were three major injuries reported in miscellaneous mines compared with three the previous year.
10. At coal mines eight of the accidents occurred in places supported by free standing supports, two where powered supports were used and only one in a place supported by rockbolts.
11. A very serious major injury accident occurred at a large coal mine, at a back ripping within a 4.8m × 3.6m arched roadway to form a 7.3m × 5.3m rectangular junction, when a contractor's heading worker sustained a punctured lung, two fractured vertebrae, a fractured collar bone and four fractured ribs when he was trapped for two hours by a fall of ground. It would appear that, as room was being made for a junction leg by another workman, there was a fall from the face of a slab of sandstone 2.1m × 1.6m and 0.2m thick which trapped the workman who was eventually released by workers from the Mines Rescue Service after receiving medical attention from a doctor and paramedics. It is considered that there was a failure to comply with the Manager's Support Rules by not providing adequate support of the face of the back rip using drop arms and associated support material.
|All - mines fall of ground accidents||Fatal||Major injury||Fatal||Major injury|
|Coal mines - free standing supports||3||9||-||8|
|Coal mines- powered supports||-||9||-||2|
|Coal mines- rockbolts||-||2||-||1|
|Coal Mines - place of accident||Fatal||Major injury||Fatal||Major injury|
Even accepting the reduction in coal mining activity during the past twelve months there has been a most significant reduction in major injury accidents. again it is of note to report that only one fall of ground accident was recorded as having taken place in a rockbolted drivage.
There has also been a welcome reduction in the number of falls of ground dangerous occurrences from seven in 1998/1999 to four this year although the incident at the gate end of a longwall face where there was a dramatic collapse, reminds us that complacency in the area of proper roof support is not acceptable.
H C Evans
HM Principal Inspector of Mines
04 June 2001