1. This report summarises the fall of ground dangerous
occurrences and major injury accidents at mines during the
2001/2002 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 affected area by a 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 sixth full year that such incidents have been
reported to HM Inspectorate of Mines.
4. Four falls of ground dangerous occurrences were reported at
mines during the year, one at a coal mine, two at a large
miscellaneous mine and one at an old mine where roadways were
being supported to give stability to the surface.
5. In coal mines the one fall of ground occurred in a main
intake roadway supported by roof bolts, that had been developed
to access reserves in a new seam. A longwall face was worked in
another seam some 60m and this resulted in some redistribution of
the maximum horizontal stress and the roadway lost confinement
and dilation of the roof occurred within the bolted height.
Remedial works were carried out but some weeks after this
movement occurred a tell tale outbye of the affected area began
to show movement of more than 25 mm within the bolted height. A
no road barrier was erected until remedial work could be carried
out. The roadway subsequently collapsed. If the managers
monitoring scheme for the mine had been complied with and action
taken promptly then the fall may have been prevented.
6. Two falls occurred in a large miscellaneous mine in main
access roads. The sections of the roads that subsequently
collapsed had been identified as suspect by the geotechnical
engineer. The setting of passive support was recommended in one
road and before the work was carried out it collapsed at a
junction area. The second road was identified but not given any
priority and it again collapsed before remedial work was carried
out.
7. The other fall of ground occurred in a mine where wooden supports were being set as part of a ground stabilisation exercise. The fall occurred in front of the supports that were being set and dislodged the last two sets of permanent support.
| Type of Support | |
|---|---|
| Miscellaneous | 3 |
| Rocketbolt | 1 |
| Total | 4 |
| Warning of Collapse | |
|---|---|
| Less than 24 hours | 1 |
| Over 24 hours | 3 |
| Total | 4 |
| Age of Excavation | |
|---|---|
| Recently driven | - |
| 6 - 12 months | 1 |
| 2 to 3 years | 2 |
| Over 5 years | 1 |
| Total | 4 |
| Type of Excavation | |
|---|---|
| Junction -girders | - |
| Junction - natural support | - |
| Junction - props and bars | - |
| Roads - arches | - |
| Roads - props and bars | 1 |
| Roads - rockbolts | 3 |
| Total | 4 |
8. There was one fatal accident recorded this year. A contract
workmen was fatally injured after being struck by a fall of coal
from the face of a passively supported development drivage. The
coal fell from a fault that had encroached into the road.
Temporary support was not being set in accordance with the
managers support rules.
Five major injuries were reported at coal mines compared with
thirteen major injuries in the previous year. There was two major
injuries reported at miscellaneous mines compared with one last
year.
9. At coal mines two of the accidents occurred in places
supported by free standing supports, one on a longwall face and
two in places supported by rockbolts. Improvements to the
managers temporary support rules, adherence to on site risk
assessments coupled with good mining practice would have
prevented the accidents.
10. In coal mines four of the accidents occurred from falls of
roof, three in developments and one when working on the AFC on a
longwall face. A fall from the face accounted for the other
accident.
11. In miscellaneous mines the accidents occurred in bord and pillar workings supported naturally, one from a fall of roof and the other when the face fell.
| 2000/2001 | 2001/2002 | |||
|---|---|---|---|---|
| All mines fall of ground accidents | Fatal | Major injury | Fatal | Major injury |
| Coal mines - free standing supports | - | 8 | 1 | 2 |
| Coal mines- powered supports | - | 3 | - | 1 |
| Coal mines- rockbolts | - | 2 | - | 2 |
| Miscellaneous mines | - | 1 | - | 2 |
| Total | - | 14 | 1 | 7 |
| 2000/2001 | 2000/2001 | |||
|---|---|---|---|---|
| Coal Mines - place of accident | Fatal | Major injury | Fatal | Major injury |
| Longwall face | - | 8 | - | 1 |
| Headings | - | 4 | 1 | 4 |
| Elsewhere | - | 1 | - | - |
| Total | - | 13 | 1 | 5 |
12. This is the first fatal accident reported since 1997. There
has been a welcome reduction in major injury accidents in coal
mines from 13 last year to five this year. The major injuries in
miscellaneous mines has increased from one to two. Although there
has been a welcome decrease in major injuries in coal mines the
major cause of accidents this year has again been due to lack of
caution or failure to comply with good practice or comply with
codes or rules.
13. The incidence of falls of ground reported in coal mines has
reduced from five to one.
14. The incidence of falls of ground has increased in miscellaneous mines from one to three. Two of the falls of ground occurred at the same mine and in similar circumstances.
J Arthur