| Dangerous Occurrence Type | DO Date | Dangerous Occurrence Précis |
|---|---|---|
| Failure of Plant - Manriding | 10/10/2001 | During normal coal carrying operations on a 1260m long × 0.97m wide mineral and manriding conveyor serving an in-seam gate road development, rising outbye with a 28m lift, the belt parted at a joint at the bottom belt inbye alighting platform. No persons were riding at the time and no-one was injured. The joint failed when some lumps of dirt trapped it at the entry to the alighting platform causing the leading side of the belt to comb out of the joint clips. Contributory factors were the joint being shorter than required due to excessive trimming and some wear of the belt carcass. |
| Fall of Ground | 08/10/2001 | At a large miscellaneous mine a fall of ground occurred in the salt horizon, driven in the stress shadow of the upper Potash workings. No person was injured and the ventilation was uninterrupted. Rockbolts formed the primary roof support when the roadway was driven during October 2000. It was then subsequently cable bolted. The fall extended for approximately 25m × 7m × 1.4m and was estimated at 300 tonne in weight. Site inspection reports by the rockbolting engineer identified during July 2001 that this area would ultimately require the setting of arches and in August this remedial work was prioritised as necessary before 31 October 2001. Temporary support procedures have now been tightened and ground control measures modified to incorporate 2.5m bolts in junction areas. |
| Fall of Ground | 24/10/2001 | Whilst timber supports were being erected within an underground roadway of a ground stabilisation limestone mines project, a fall of roof occurred on the edge the roadway dislodging and collapsing the last two pairs of permanent support frames. No one was injured and workers were withdrawn until the situation stabilised. Investigations revealed no obvious defects in the standard of support work but did highlight the presence of a significant discontinuity within the immediate roof strata. Work had just restarted in this area having been suspended for three months when the ground could have settled, which may have contributed to the incident. The use of increased support bracing and erection of steel supports frames will take place when significant roof discontinuities are encountered in future. |
| Fall of Ground | 03/11/2001 | In a main roadway drivage supported by roof bolts and strap bars, a fall of ground was discovered during a weekend inspection. The length of the fall could not be determined, the height was estimated to be up to 3m and the width 5m. A longwall face had been recently worked in a seam some 60m below leading to a redistribution of the natural maximum horizontal stresses, causing a loss of confinement and movement within the bolted height. Remedial work was started and the movement arrested by the setting of long tendons. Some weeks after this work was completed a tell tale outbye of this area began to show dilation within the bolted height of more than 25mm. The roadway subsequently collapsed. |
| Fan Stoppage | 12/11/2001 | At a large mine a 6600 volt circuit breaker opened and caused loss of supply to a booster fan lasting for 56 minutes. No adverse conditions resulted. Further investigation is to take place into the cause of the problem with the 6600 volt circuit breaker. |
| Fire Underground | 25/10/2001 | Underground at a large miscellaneous mine, fire broke out in the engine compartment of a large crawler mounted diesel powered roof scaler which could also operate using an electrical supply. Indications were that during electrical operation hydraulic oil from burst hoses had penetrated insulation and was ignited by the hot exhaust when the diesel engine was used for infrequent tramming. Oil soaked salt accumulations on engine surfaces were subsequently ignited. The fire was rapidly extinguished by an onboard fire suppression system. No persons suffered ill effects, and no damage to equipment resulted. Preventative measures included, improved hydraulic hose protection, provision for cleaning down engines on equipment that does not regularly return to the garage area, and improved maintenance of exhaust insulation. |
| Locomotives | 04/10/2001 | In a large main roadway with a materials landing installed, a locomotive became derailed. The locomotive had passed over a checkrail and shunted materials back onto the landing, and when it was passing back over the rail, to come outbye, the front wheels dropped off the track. A bolt intended to secure the checkrail had not been used for some time. |
| Locomotives | 18/10/2001 | While hauling a single covered manriding car at slow speed along a main return coal clearance tunnel on a slightly rising straight track, the front bogie of a Clayton 50hp rubber-tyred Bo-Bo locomotive, derailed bringing the train to rest. No-one was injured and no serious damage was caused. Several small lumps of dirt fell through a heavily corroded piece of mesh lagging and dropped onto the track as the locomotive was passing. The driver braked but could not prevent the wheels riding onto the dirt. |
| Locomotives | 27/10/2001 | At the junction of an inbye manriding station with a main return roadway a Clayton 90hp locomotive, travelling inbye with five empty manriding vehicles attached, derailed at slow speed as it traversed a curved section of track. The curved track had suffered due to recurring floor movement where the curve had been relayed on a previous occasion. Following the incident, and subsequent relaying of the curve, track movement was still apparent where ballast had not been packed tightly below sleepers. |
| Locomotives | 21/11/2001 | At a large coal mine a 150 hp Co-Co locomotive derailed on the leading set of wheels as it negotiated a curve. At the time of the incident the locomotive had been pulling, at slow speed, a skateboard with a salvaged cable attached. Inspection reports from the previous day indicated the need to pull the track over to improve clearances for salvage. The afternoon shift recorded pulling the track over but noted that it required ballasting, but this was not done |