When production had started at Riccall in Jan 1988, the conditions at the bottom of the Bunker 7 and Bunker 8, which was the furthest point in the spine tunnels at Gascoigne Wood were extremely hot and dusty. Booster fans were urgently needed to cool the area and improve ventilation. A 1 in 7 drift was driven from the North Intake at Riccall Mine into the Gascoigne Wood Wood south spine tunnel to remedy the ventilation problems.
Riccall Mine / Gascoigne Wood, 1 in 7 Booster Fans.
AMCO were given the contract to drive the heading with a Dosco Mk2A revised hydraulics roadheader. The heading started in April 1988 and finished in March 1989. The heading drove on a 30° dogleg for 30m then turned north east to drive at an incline of 1 in 7 under the Riccall Bunker area and completed at the junction where the south spine Robbins TBM was laid to rest.
The heading was driven from a junction 500m outbye from the North Intake junction with Bunker 7. A conveyor was installed from the 1 in 7 junction to the bunker 7 conveyor coming from the Riccall bunker. A drift conveyor was installed loading onto a short conveyor to the North Intake junction. This conveyor loaded on to the floor where it was pushed outbye into the North Intake slusher bunker. The heading muck was loaded at a later time, using the slusher, onto the conveyor. This allowed for sufficient cutting muck storage.
As the 1 in 7 heading progressed it cut through the Dunsil and Swallow Wood seams as it passed throught the cross measures. Two Pikrose haulages were installed in the short heading and the 1 in 7 drift heading, at the top junction, to supply the development and transport the substation installation equipment. Two hundred metres from the Gascoigne Wood junction the heading was widened and two parallel headings were created either side of the main heading for the booster fans installation. The heading continued forward and completed to Gascoigne Wood in early 1989.
At the booster fan switchgear site, concrete tiered pads were created for the 6.6kv substation, including 3x 6.6kv MIVAC switches, a 6.6kv HF2VG double drive control panel for the two 750kw booster fans, local 6.6kv/1100v transformer to supply the Elram control panels, MINOS outstation and lighting transformers. Double electrical Elram operated ventilation doors were installed in the main roadway outbye of the substation.
The 6.6kv supply for the substation was a dedicated supply from the surface via No1 shaft to a MIVAC shunt trip switch in the No1 pit bottom main substation. 250m lengths of 120mm 6.6kv armoured cables were run from the substation along the North Intake roadway and were connected using Scotchcast inline joints. It was quite a job jointing and hanging the cables in the middle of winter in the main intake.
When the 6.6kv supply was energised the commisioning of the fans took place. Booster fans are an integral part of a mine ventilation system so many air pressure, air velocity, methane level, leakage and flow checks were made as part of the environmental systems at both Riccall Mine and Gascoigne Wood to ensure no problems were caused with the new installation.
The control, monitoring and system transducers on the fans were checked including fan vibration, bearing vibration, bearing temperature, air pressure, air flow and automation system for stopping and starting the fans from the surface control room at Riccall. When all the checks were made the fans became operational.
Water pumping systems were also installed at the spine tunnel tail end which used the 1 in 7 Drift to clear mine water via Riccall Mine.
Line drawing of the North Selby Mine Conveyor System.
Drawing and information kindly provided Dave Free, S.C.E. (systems) North Selby Mine.
Due to the sheer size and expense of developing the Selby Coalfield, plans were revised, not only for costs, but to overcome mining problems. The original plan was to drive the Gascoigne Wood spine tunnels to 14,930m so that Stillingfleet and North Selby Mine had a direct connection to the spine tunnels through two, 2000 tonne, 70m bunkers. The complex was planned to have 11 bunkers. This did not happen. To overcome this change of plan a connection was to made with Stillingfleet Mine for the coal clearance of the North Selby Mine via the Stillingfleet bunker onto the Gascoigne Wood spine tunnels.
The tunnel connecting Stillingfleet Mine with North Selby Mine was 3600m long. The tunnel was driven from both ends and was completed in July 1989. The North Selby drivage used a Dosco MK3 roadheader.
Dosco Mk3 Roadheader.
The face main gate conveyors were standard 1100v twin drives with automated loop take up which were PIAB load cell controlled. H801s and H802s, the first two faces, loaded onto a conveyor which delivered onto the H801s slit conveyor to the South West Transport Road Conveyor. This was a complex, one off, conveyor. It was downhill 1 in 20 incline with a jib loop tension take up. It had a standard loop take up at the rear of the drive with retarding structure to keep tension during start up due to the incline. This was achieved by using two PIAB load cells to control the tension during start up.
PIAB load cell.
The PIAB load cells were used throughout the Selby Coalfield and were used as part of all conveyor tension control systems.
The South West Transport Road conveyor delivered coal onto the Bunker Slit Conveyor. This conveyor also had coal loading from the South East coal faces starting with H901s in Nov 1990.
During the development of the South West Transport Road the heading hit a fault. Water was issuing into the heading which was tested for chemical constituents and was found to be 5 times saltier than sea water and was as warm as a hot shower. The surrounding rock was also very warm to touch.
The Bunker Slit Conveyor was a 120 kw single drive conveyor which loaded onto the 1 in 4 Drift Conveyor. The North Conveyor also loaded onto this conveyor which delivered coal from the North West faces, H851s and H852s. The 1 in 4 drift was created to give North Selby Mine a 70m, 2000 tonne bunker to allow for problems in the coal clearance. The Bunker Infeed conveyor was 1 x 750 kw Gullick Dobson drive fitted with torque responsive disc brakes operated by a load cell placed under the gearbox superstructure due to the incline. This conveyor took the entire production of the pit and delivered it into the Staple Bunker.
The Staple Bunker had a twin Westerland hydraulic speed control feed onto the West 1 Conveyor which was a 1×750 kw Gullick Dobson steel cord conveyor. This delivered coal onto West 2 Conveyor, a 2×750 kw Gullick Dobson steel cord drive which loaded onto the Stillingfleet East Conveyor.
I was attending Selby Mines Rescue station for my annual medical and treadmill fitness test when a rescue officer told me that conditions on H439s coal face at Riccall had got worse and the CO levels had started to rise due to the heating on the face. The face had a slip fault 70m from the main gate and the coal left in the gob was causing an heating.
Coal mines in the UK are required to have prepared sites with sealed concrete blocks walls started at the required dimension in all gate roads to a coalface.
The explosion proof seals in both roadways to the H439s face had been started. Equipment and resources were being transported to the Fresh Air Base for the stoppings to be made. I was told if carbon monoxide levels got any higher that rescue teams will be called to complete the stoppings. I returned home for some lunch when my alerter was activated. I phoned the Rescue Station and was told to go to Whitemoor Mine and that an emergency incident had been called due to the heating getting worse. The underground access at Riccall Mine was suspended for safety reason and all staff attending the heating on H439s face had to access the face from Whitemoor Mine.
When I arrived at Whitemoor Mine I was told that a Fresh Air Base had been set up between H439s main gate and tail gate. Rescue officers were underground and a Selby Rescue Station team were en route to H439s. I was told by the surface senior officer of the incident to go to the canteen and wait.
30 minutes passed by when the senior officer came to the canteen and called for a team to go underground. The team was chosen and I was made captain as I worked at Riccall and I had knowledge of the mine and the face, as I had been working on it the day before.
All men had been withdrawn from the mine except for a minimum staff of officials and craftsmen to cover the concrete pumping operations. All person going underground had to do so using the emergency check system at Whitemoor Mine. All operations were controlled by the Senior Rescue Officer at Whitemoor Mine Surface Rescue Control.
After checking and donning our S.E.F.A. breathing apparatus in the rescue room we gathered all our equipment which included, a mine plan, Whirling hygrometer, Sked stretcher, Microvent resuscitator, Drager gas sampling tubes and pump and Status Mentor gas analyser and the team went underground. We were transported by rope haulage from Whitemoor Mine pit bottom as far as possible in the West Conveyor Road towards the Whitemoor Bunker area. We then continued on foot to H439s Fresh Air Base which was approximately 3500m from the pit bottom. When we arrived at the F.A.B. we were told to relax and wait on standby. After an hour we were called and given a brief. I was told that the carbon monoxide levels were rising and to check the CO levels regularly and hydrogen cyanide, a toxic gas produced when plastic mesh burned. Our first task was to start installing an air sweetening system from the Fresh Air Base.We then had a 2 hour spell in breathing apparatus, building and pumping concrete at the tail gate stopping site. The team then went back on standby, as a safety team for 2 hours until the next relief team arrived. .
When the relief team arrived, we were released from the fresh air base and were told to return to the surface. Once on the surface we had a debrief then cleaned, recharged and serviced our SEFA breathing apparatus so they could be re-used. We completed all the necessary training records and Captains Report for the incident.
Operational experience report for H439s.
I returned to Riccall Mine to attend a meeting regarding the situation on H439s. By the time I arrived home I had been awake 26 hours and ready for some sleep.
On completion and simultaneous sealing of the maingate and tailgate explosion proof stoppings all men were immediately evacuated from the mine and nitrogen was pumped into district from the surface pumping rig supplied by NOWSCO. The mine gases behind the stopping were checked using tube bundle monitoring. The sealing process proved successful with no methane ignition recorded on the mine environmental monitoring system.
Note; The reason nitrogen, an inert gas, was pumped into the district with an heating was to lower the oxygen level below a point where combustion can take place. When a district is sealed, methane gas levels can quickly enter the explosive range of 5% to 15%. If the oxygen levels are reduced below 13% before the methane levels reach explosive range no ignition can occurs. The company who provided the nitrogen pumping service was called NOWSCO, an oil well service company, who specialise in pressurising blocked pipelines.
This video snippet shows the filling of North Selby mine shaft in October 2000 after the mine had ceased production. It shows the No1 winder house, No2 Winder house and Fan house.
Gascoigne Wood Mine and Selby Mines Rescue station.
This video snippet shows the Gascoigne Wood Drift control room, conveyor drive house with the drive systems visible and drift man riding haulage. It also shows the Mines Rescue station S.E.F.A. breathing apparatus and training galleries.
Stillingfleet Mine.
This video snippet shows the lamproom, No1 winder in operation and cage detaching gear, No2 Koepe 6 rope friction winder in operation and the Fan house.
Videos were filmed by IA Recordings who kindly gave me permission to embed the snippets.
The South West Trunk road was driven by Thyssens using a Dosco Mk3 roadheader. The roadway was driven from the West Conveyor at H472s cross slit to the south of the mine to connect with Whitemoor Mine. It was driven in two sections. The heading started in Aug 1989.
The South West Trunk.
The first part of the South West trunk headed south and created junctions for H478s maingate and H479s face. H480s junctions were started at slightly later date. They then continued onwards to create a major junction for the South West Lateral, known as Angina Hill. The heading then continued towards the demarcation with Whitemoor Mine to join with the Whitemoor West Conveyor roadway to create an intake roadway. When the heading got to the South West Lateral junction the coal, due to a downthrow fault, dipped so a small shallow drift was made. The heading then continued to the Whitemoor connection creating 2 further face junctions for H437s on the westside and H439s face on the eastside of the heading. The original plan for this area of the mine was to continue 1000m with the South West Trunk heading a and create a further junction. At this point a lateral roadway was to be driven to develop faces at the West and East. This development never happened.
Dosco Mk3 Roadheader
The furthest face to be worked from the West Return of the mine was H477s. This face was on the boundary with Wistow Mine. The face finished in September 1995 and was made ready to be transferred to the first face on the South West Trunk which was H478s. This face was planned to start in early 1996. This face used the West Conveyor Road as the tailgate for the face so only the maingate had to be driven.
The H477s pantech of electrical equipment and transformers were sent out of the mine for overhaul leaving only a pump and tank for the transfer. The stageloader, face supports and AFC were tranferred from the maingate through the cross slit between the Return and Conveyor road straight onto the new face. A refurbished electrical pantechnicon including pumps and tanks was installed from the surface via the new H478s maingate. As the face retreated it had to passed through every junction from H477s to H472s which was quite a task due to the height of the return roadway.
The face had retreated 200m when an urgent modification was needed to both of the transformer Wallacetown B80 LT end supplies. They needed replacing urgently due to a technical problem with some internal contacts. We spent two very long weekend shifts getting the new switchgear onto site, removing the faulty switches, fitting new items and getting the defective unit out of the pit. The face progressed well and was completed in September 1996.
The face equipment from H478s was transferred to H471s.
The next face to be developed from the South West Trunk Road was H437s. This face was developed at the inbye end of the trunk road near to the junction with the South West Lateral.
This face was installed in late 1996 using Longwall International equipment with an Anderson Strathclyde AM500 DERDS. The next expected face developments to the south were never started and when H437s face had retreated a short distance a seismic survey was carried out from the main gate testing the seam to the south of the mine. This survey apparently showed that the coal had faulting and due to the low risk mining strategy undertaken by RJB Mining, a huge area of coal was abandoned to the south of Riccall Mine. H437s proved to be a good face with no geological issues. Wistow Mine subsequently worked 3 longwall faces, H93s, H94s and H95s adjacent to H437s. The area of the coal abandoned was equivalent to the coal worked at Riccall Mine during it’s production life.
The next face to be worked from the South West Trunk was H479s. The 1500m face developments were started in January 1998 using Lee Norse LN 800 Continuous miners. The 150m face line was situated on the Wistow Mine boundary at the side of H46s and was worked from West to East. The face was equipped with a Joy 4LS shearer and face equipment. The electrical equipment and pumps were ex H437s. The face started production on 10th August 1999 and completed production in 6 months on 28th February 2000.
The last face to be worked from the South West Trunk was H480s. This face started development in November 1999 and started production on 24th August 2000. The face headings were 1250m long with a face length of 230m. This face was installed with Joy equipment, Joy 4LS Shearer and a 3.3kv Baldwin and Francis CHL Load centre (ex Kellingley Colliery) to control the electrical equipment. The face produced extremely well and was completed in 8 months.
Plan showing all the faces worked at the West and South West of Riccall Mine
Plan showing the South West development from the South Intake roadway.
The South West Conveyor lateral roadway was started in November 1991 by mining contractor AMCO using a Dosco LH1300 roadheader.
When the Dosco LH1300 arrived at Riccall Mine it was painted a strange pale blue colour. I later became aware that machines in this colour were owned by the contractors AMCO.
Dosco LH1300 Roadheader.
The heading was driven on an uphill incline from the South Intake junction heading towards the junction with the South West Trunk being driven by Thyssens and was nicknamed Angina Hill. At the same time a cross slit and conveyor was developed from the South Intake towards the South Conveyor to transport coal from the faces planned in the South West area. When the connection was made with the South West Trunk this roadway became the supply road for the trunk roadway. A manriding conveyor was installed when the connection was made.
The first face to be developed was H430s which was driven 800m using LN800 continuous miners and started production in September 1992. The face equipment and A.F.C. were Dowty Meco equipment similar to H444s but with a new rail mounted pantechnicon, electrical equipment, transformers and pumps. The shearer was an Anderson Strathclyde AM500 DERDS. The face retreated from north to south and progressed well completing production in May 1993. The face equipment was salvaged and transferred to H432s face.
The South West faces ( H437s, H438s and H439s not shown)
As the South West heading progressed, junctions were made for four faces, H430s to H433s, to be worked to the north. A roadway was later developed in 1995, heading South from the lateral to develop H438s and H439s faces.
H432s, which had gates of 1200m, started production on 26 July 1993 and completed in Jan 1994 for the equipment to be transferred to H433s face which was 1000m. This face started production in March 1994 and completed in late September 1994. The equipment was transferred to 1000m, H431s, which started production in November 1994. All the faces in this block of coal were developed using Lee Norse LN800 continuous miners and created european drivage records during these developments.
Lee Norse LN800 continuous miner.
The faces were successful and helped Riccall to achieve record production figures during this period. All the faces were equipped with Dowty face equipment and Anderson Strathclyde AM 500 DERDS shearers with identical rail mounted electrical systems and were all supplied using Clayton BoBo locomotives. The last face on the north side of the South West, H431s, completed production in mid 1995. The next face H438s, was taken from the south side of the South West roadway. A slit was driven going south and a short face was developed with the headings driving West towards the South West Trunk. This face was installed using H431s equipment and started production in Sept 1995 and finished in Mar 1996
The slit gate from the South West roadway continued for 300m and a further face H439 was developed. The face development roadways went all the way to the South West Trunk. The face was installed in the slit gate from the South West roadway. This face used the equipment from H438s.
H439s had a huge slip fault, what we knew as a white wall, 70m from the main gate. This caused huge problems with the shearer and chocks due to the steep angle of the fault. The problems with bad ground around the fault stopped production for periods of time to enable grouting in the faulted area. Eventually the face conditions became too unsafe and the face was abandoned at the half way mark. Attempts were made to salvage the face supports but due to coal being left in the waste area at the back of the face from the faulted area an heating developed, known as a gob fire and the face had to be sealed off. Explosion proof seals were immediately instigated at the face gate ends off the South West Trunk roadway. When they were completed, nitrogen was pumped from the surface, via an existing pipe range, by a rig supplied by NOWSCO to control the heating but the face and all the equipment was lost.
In early 1990 the third phase of the development of Riccall Mine started. A roadway was driven from the first junction 500m from the pit bottom in the North Return. The roadway was driven at 45° to the junction and was the start of the East Side of the mine. The cross slit was completed in Sept 1990 with three headings planned to be taken from this roadway, the East Conveyor, East Return and 2nd Return to the pit bottom. This roadway was the East Booster Fan Return.
Plan of East Development cross slit.
The start of the East Conveyor roadway was from the North Return driving East and was started in January 1990. The heading was completed to the east developments cross slit in May 1990 and the conveyor was installed for the lateral headings. The conveyor loaded onto a newly installed conveyor in the North Return which loaded into the Riccall bunker area.
Thyssens were given the contract to drive the East developments. The East Conveyor and East Return were driven at a 1 in 17 downhill incline using Dosco LH1300 roadheaders and were started in Oct 1990.
Dosco LH1300 Roadheader.
As the east lateral headings were developed, junctions were created at H500s and H501s. The cross slit was created for H501s main gate and the face headings for H501s face were started from the East Return. The face retreated from South to North. The Lee Norse LN800 machines were tracked on power from the west of the mine to be used for the H501s face headings.
Lee Norse LN800 Continuous Miner.
The East Side from H501 to H505s.
East Side from H499s to H503s.
In April 1991 when the heading team were starting the face roadway for H501s, the 2nd East Return was started. This Thyssen’s heading was driven using a Dosco LH1300 and headed south, back towards the No2 upcast shaft, parallel with the North Return. At the No2 shaft end a new inset was constructed 20m below the manriding level, which was completed in Dec 1991. A booster fan was installed to improve the air flow to the east headings and faces. It was completed before H501s face commenced production.
A little side note to this fan installation; After a couple of years of running, the fan started to show a slight increase in vibration on the MINOS monitoring system. The vibration increased over a few days and a few people were getting very concerned. Gary, my mate who was a whizz on the Vibration Spectrum Analyser, loaded the fans installation data into the machine and did some tests on the fan. He found the vibration to be one particular fan impeller with dusty debris build up. A planned stoppage was organised and the problem was sorted.
2nd East Return showing booster fan.
The H501s tailgate heading was started in Mar 1991 and completed in Sept 1991. The machine turned east to cut the faceline which was completed in Nov 1991. The LN 800 then turned north to start the main gate heading back to meet with the main gate LN800 which started cutting in Nov 1991. The headings connected in Feb 1992 and both machines were driven off the main gate together to start the H502s face developments which commenced in March 1992. The face commenced production in May 1992. The face was 240m long and the gates were 1300m in length at a depth of 825m.
The face equipment on H501s was ex south side Dowty face supports and A.F.C. which had been overhauled and redesigned to be compatible with the new 390kw Joy 4LS shearer. The electrical equipment, pumps and two, 1 MVA transformers were rail mounted with a Wallacetown M82 face isolator situated outbye and 100m of type 6.6kv type 631 pliable wire armoured cable to allow for the face retreating. At the inbye end of the main gate, an Hausherr dinting machine operated where the stageloader loaded onto the conveyor. 30m of flexible, double back to back Bretby was used to protect all the face cables and hoses where they went from the pantechnicon into the stageloader cable protection troughs and to allow for the face retreating. The 150kw stageloader had a 150 kw crusher/ sizer and the face panzer had two, 150 / 300 kw 2 speed motors.
Due to the 825m depth of the workings, roadway conditions were slightly concerning with floor blow becoming apparent. The maingate was started with a remedial system of cable bolting carried out by a new team set up at the pit. 28 foot cables with concrete grout were used for these secondary supports. The bolts were crossed and tensioned to create what looked like an heavy duty basket weave across the roadway. This system of support became the standard practice on all developments at the east of the mine.
H501s performed very well. Floor blow in the tailgate was a concern so extra concrete support chocks with steel wire reinforcing called Fibcrete Blocks were installed near to the tailgate face entry but extreme floor heave still caused problems causing very confined working, especially for the methane borers at the back of the face.
H501s finished production in Jan 1993 and H502s started production in Feb 1993.
Due to the problems with extreme floor blow on H501s the cable bolting support system was introduced whilst the headings were being developed on H502s. Before the face started production a three man dinting team was set up to pre dint the main gate outbye of the pantechnicon. The dinting team lifted the rails and conveyor in sections and cut 1m of floor muck. The equipment was then restored. The three man team used a Dosco Dintheader with a MC3 Scorpion tail loader.
Dosco Dintheader
Mavor and Coulson MC3 Scorpion.
The dintheader cut the floor which loaded onto a monorail mounted bridge belt and onto the front of the MC3 loader. The muck was then loaded via the swivelling scorpion tail onto the maingate conveyor. The MC3 was designed in the 1950s and was a machine from a bygone era but proved to be a very versatile machine.
As the East lateral roadways progressed a further machine was introduced by Thyssens. The Voest Alpine AM75 was a low profile machine and weighed 58 tonnes. It had a transverse cutting head arrangement with a 200kw cutter and a total power of 350kw. The machine performed very well. The other machines used were a Dosco LH1300 in the lateral roadway and a Lee Norse LN800 continuous miner to develop the face roadways. As the East side of the mine developed the temperatures became extremely hot due to the depths and distances. The headings were over 40c and heat exhaustion became a problem.
The face development roadways at the East of the mine were gradually getting longer. The coal clearance conveyors were getting too long for a single conveyor drive to handle the production from the face so booster belt drives were installed on maingate coal clearance conveyors. The booster conveyors were installed 150m inbye of the main double 150kw drive gearheads . The booster belt was the same rating of 300kw but ran inside the existing conveyor. Due to the weight of the coal on the top conveyor the belt pushed down onto the lower booster conveyor which assisted with the load due to friction between the conveyors. Booster conveyors were used on all the east side coal faces from H503s to H506s due to the coal face production conveyors being in excess of 2000m.
The first time I heard about this type of conveyor drive was when my dad was part of the mechanical team who installed a booster drive on the Royston Drift Mine, main drift conveyor.
At the end of 1993 the installation of a new Steel Cord Conveyor was started. The conveyor was a double, 6.6kv, 750kw drive with an option to add a third 750 kw drive. The drives had scoop starters with huge, double disc braking anti roll back system. If all 3 drives had been used it would have been the most powerful conveyor drive ever installed underground in a coal mine at the time of installation. Only 2 X 750 kw drives were ever used. The substation, 6.6kv NEI Peebles HF2VG switchgear and control equipment were sited between the end of the East Return and the North Return roadway on a large suspended Purdy platform set back to allow the huge drivehead sections and 16 tonne rolls of steel cord conveyor to pass through. A large clamping and vulcanising station ( cooking facilities) was built at the end of the drivehead for the conveyor belt jointing.
The conveyor delivered onto the Riccall Steel Cord Conveyor via a short 1 in 3.4 Drift at the outbye end of the East Conveyor. This short Drift was completed in April 1994.
The conveyor was installed when H502s finished production. The return end was inbye of H504s maingate and became a manrider when the installation was completed.
When the H503s gate developments were completed a face line was driven from the maingate to the tailgate. As the faceline was being cut, the conditions in the heading became very problematic with floor blow and heavy weighting happening as the roadway was developing. It became apparent that the roadway was becoming unusable as a faceline. The heading was completed and the Lee Norse LN 800 machine was tracked out of the tailgate 100m and a junction was created for the new faceline. This was cut from the tailgate to the maingate. The original faceline was used as a sacrificial heading to take the weight off the new development and was allowed to close up. This caused a problem for production due to the delay in developing a new faceline heading so a decision was made to build the entire pantechnicon in the maingate between the new faceline junction and the sacrificial heading. This allowed the faceline to be completed and the removal of the heading machines by tracking out to the new H504s face developments. The face A.F.C. gearhead, stageloader and crusher, pumps and electrical equipment were installed in the disused inbye roadway. The equipment was then pulled into position when the faceline was completed and the heading machine were removed from the maingate roadway. This was the hottest place I have ever worked in a mine with temperatures of 50c due to roadway air flow in the severely restricted faceline roadway.
During the conveyor installation, the face installation on H503s face was completed using the equipment from H502s. During this period there were no manriding conveyors so a lot of long walks were involved with some very long shifts in extreme heat as the face gates were 2000m in length and an overall walk of well over 4000m from the pit bottom to the face and back at the shift end up the 1 in 17 East Conveyor Road.
H503s proved to be a very good production unit due to good face conditions and main gate roadway dinting taking place to relieve extreme floor heave. The face completed production in December 1994.
The next face to be worked at the East of the mine was H504s. To say that this face was a disaster is an understatement. The face headings were developed using LN800 Continuous miners with supplementary cable bolts as supports. H503s face equipment was transferred and installed. Production started in early 1995. The face started ok but within 200m of retreat the face conditions became very heavy with severe cavities and faulting. Many remedial systems of face repairs were tried including different types of concrete pumping, grouting and cable bolting.
A pumped, two part resin glue brought from Germany was tried with some success. Unlike standard roof bolting, using resin capsules, this polyurethane two part resin is injected through the hollow bolts called IRMA’s, under pressure, after the bolt is inserted. The polyester fills the surrounding strata around the bolt including any cracks in the surrounding rock and ensures complete encapsulation when working in bad ground.
(Above information kindly provided by Denis Allchurch, Deputy and Mine Manager at Riccall Mine)
The face conditions were so bad that production ceased for weeks on end. As the face was being cut it was collapsing with the chocks eventually unable to move due to severe weighting. The A.F.C. became unusable due to the amount of stone and weeks were spent clearing the panzer. As the face retreated the cycle of roof collapses continued and equipment became unusable. The decision to abandon production on H504s was made and the face finished on 17th April 1997, 200m short of the planned finish mark.
The next face was H505s face which was developed and installed during the production run of H504s. The face gates were over 2000m long. A brand new set of Joy equipment was installed on this face. It was the first time an LC33 electrical Load Centre was used at Riccall Mine. The Joy 4LS shearer, A.F.C. and crusher/ stageloader were all 3.3kv.
The panzer and crusher / stageloader were fully automated using a Davis outstation to control the face coal clearance which was another first at Riccall Mine. Production started in 1996 and completed in 1997. The face was a total success, with very good production figures, very unlike the H504s nightmare face.
During early 1996 a junction was created in the East Conveyor roadway opposite H505s Main Gate. This heading was called the North East Development. The heading was driven to the north of the mine by Thyssens contractors using a Dosco LH 1300 Roadheader. When the heading had progressed 200m it turned 45° and started driving on a North Easterly direction. A 6.6kv supply and electrical substation was created for the North East faces at this junction. The lateral roadways were to develop up to twelve longwall faces starting with H514s but were never developed as the mining contractors were withdrawn. This area was abandoned in August 1996.
The next face to be worked at the east of the mine was H500s. This face was a shorter face at 150m and was installed in early 1998. The face was totally automated using LC1100 and LC33 load centres with a Davis Outstations controlling the face coal clearance and face support pumps. It was a very high tech face and produced very well. The face was completed in four months starting production in June and finishing in October 1998.
Throughout the history of mining, methane, which is a highly explosive gas with an explosive range of 5% to 15% in air has always been a major problem to the people working underground. Ventilation is the primary requirement for keeping the methane levels below the safe level of 1.25%. Thousands of explosions have occurred due to badly planned or insufficient ventilation in coal mines. When planning a mine, the fresh air drawn through the pit has to be of sufficient pressure and flow to remove the gases produced underground and keep them within set safe limits. There are many parts of a mine ventilation system used to achieve this including, the main fan, auxiliary fans, booster fans, air doors, regulators and air crossings to name a few.
When a coal face is mining, billions of cubic litres of methane are produced which has to be safely managed. The main way of achieving this is to supply vast quantities of fresh air at sufficient pressure and flow to deliver the quantity to dilute the methane passing through the face. The Selby Coalfield main fans were very powerful at 2,100kw and could draw upto 360 cubic metres of air per second around the mine to achieve the quantities needed.
A further control measure is to stop the methane getting into the air flow in the first place by drawing the gas from the strata above and below the working coal faces and sending it to the surface in pipes. This process is called Methane Drainage. The Barnsley seam worked in the Selby Coalfield is famously very gassy so Methane Drainage was planned during the design of the complex.
Riccall Mine used the same system of Methane Drainage during the life of the pit. The tailgate of every face had a system of boreholes drilled into the gob at a minimum distance of 10m at the back of the face line. This distance allowed for the strata in the gob to fracture and settle. If the holes were drilled too close to the faceline the standpipes were prone to being sheared when the gob settled. The system described below was used on all faces at Riccall Mine with the exception of East side of the pit.
Methane borers drilling top holes with mini Hydrac Drill Rig.
The top drainage holes were drilled at 60 degrees towards the gob every 15m in the tailgate roadway. The holes were bored using 18 x 2 feet 6 inch drill rods. The 18 x 2 feet 6 inch drainage standpipes were then installed into the hole with denso tape on each joint to seal the pipe into the hole. A stuffing box was then installed on the last pipe. The next stage was to drill a 50mm hole up through the standpipe with a further 42 x 2 feet 6 inch drill rods added onto the length of the hole giving an overall drilled length of 150 feet. This was called the production length and passed through the next 2 seams above the Barnsley seam called the Dull and Kents seams. The standpipe end was then connected to the methane drainage pipe range using a flexible 2 inch rubber hose. A hole was manually drilled into the methane range for a threaded connector piece for the pipe connection.
The methane borers had to work at the back of the faceline so ventilation was very important. The tail gate end of the face had steel reinforce supports called Fibcrete chocks installed as the face retreated. An anti static sheet, was fixed to the Fibcrete chocks, which regulated and directed the ventilation into the area at the back of the faceline where the borers were working.
The bottom holes were drilled at 60 degrees downwards towards the face every 40m in the tailgate roadway. The hole was drilled as above but only 8 x 2 feet 6 inch standpipes were installed with a stuffing box on the last pipe. The pipes on the down holes were sealed with oil well cement to ensure there was no water ingress from the lower strata. The 50mm diameter, production length was then drilled to an overall length of 150 feet passing through the Dunsil and Swallow Wood seams. The same process as above was used to connect to the pipe range. The methane drainage pipes were called pipe “A” and “B” and were 8 inch in diameter. Pipe range “A” was the ex compressed air range used for the heading development. Pipe “B” installed by the methane borers just before the face started production. Both pipes were laid in the rib side as the face retreated.
Hydrac Drill Rig and Power Pack.
The machine used to drill the drainage holes was called an E.D.E.C.O. Hydrac Drill Rig. Hydrac rigs were designed to have a drill stroke of 2 feet 6 inch to accept the drill rods of that size. A mini Hydrac rig was designed to have a drill stroke of 1 foot 3 inch for very confined spaces and heavily weighted roadways. The rig was supplied by hydraulic hoses from a pump which was situated slightly outbye of the faceline.
The transition from arch girders as primary supports to full roof bolting made a huge difference to working conditions for borers. The tail gate area became very confined and difficult for the lads doing the boring especially when working in the east of the pit due to the depth of the seam.
H472s tailgate using arch supports.
H475s tailgate with roofbolt supports.
Due to the difficulty and confined work and having to man handle the hydraulic rig, a specially designed hydraulic portable rig was designed for use in the Stanley Main seam in 2002. It was obviously called “The Moon Buggy”.
E.D.E.C.O. portable Hydrac rig (Bigbird’s Moonbuggy) used on SM 501s.
The 2×10 inch pipes with the trouser leg adaptor pipe at H504s Tail Gate end.
Due to the huge amount of methane produced at the east side of Riccall Mine the system was upgraded by using larger, 3 inch diameter standpipes, 65mm diameter borehole production length and 2 x 10 inch diameter methane ranges. The 14 inch pipe used in the return roadway was also upgraded to a GRP pipe.
At the outbye end of the tailgate, the two methane pipes were connected to the main methane range via a connector called a trouser leg. This pipe was 14 inch in diameter with methane monitoring sample tubes, pressure gauge, and manometer for testing purposes. The 14 inch methane range was installed in the return roadway and delivered the gas to the surface methane plant via No2 upcast shaft.
The surface methane plant contained four, Nash Vacuum pumps. The pumps operated automatically due to demand and were initially designed to vent the methane gas into the atmosphere.
In the early 1990s, the methane was used to generate electricity. The gas was sent to a separate filtration unit and gas turbine generator, manufactured by Dale Engineering.
Information kindly provided by my mate, Glenn Bryan ( Big Bird ) who worked as a Methane Borer on every face at Riccall Mine.
From production starting in January 1988, Riccall Mine was a great producer of coal. It had it periods where individual faces were problematic but due to working multiple faces the production remained high throughout it’s working life. It was the first mine in the complex to produce more than 2 million tonnes in less than a year on 14th March 1992 finishing the year producing 2,200,000 tonnes.The following year year production was up again to 2,579,000 tonnes and in the year of privatisation, Riccall produced 3,060,000 tonnes, the first pit in Europe ever to produce over 3,000,000 tonnes of coal in a year.
In its short life of 16 years Riccall worked 43 longwall coalfaces with exceptional production figures over the life of the pit. It was also the only mine in the Selby Coalfield to work two seams, the Barnsley and Stanley Main seams. The Stanley Main seam faces were designated SM and were worked over the east side coal faces.
When I started at Riccall Mine in 1986 the mine had a system of maintenance which was relatively new in the industry called the Routine Condition Monitoring or R.C.M. The team consisted of mechanical staff initially who carried out weekly monitoring of all equipment throughout the mine. Fans, machine gearboxes, motors, compressors, conveyor gear heads and rollers were all monitored. The system was based on testing an item of equipment, when brand new to set a baseline for the vibration profile for the item. The equipment was then analysed for vibration on a regular basis using a machine called a shock pulse monitor or S.P.M. Any irregular vibrations were picked up, investigated and monitored to ensure catastrophic failure didn’t occur during production. S.P.M. was the electronic device used in the development of this type of maintenance and it worked well in the early years of this technologies. The other major part of the system was gearbox oil debris analysis. Oil samples were taken on a regular basis from all gearcases. The oil was mixed with a solvent solution to remove the oil. The sample was then passed through a filter to gather any debris. The solvent was evaporated leaving a debris sample. This was analysed for types of metal particles or dirt. All the gathered information was inputted into the data monitoring system so that deterioration of internal bearings, rotating parts and oil deterioration due to ingress of dirt were picked up at an early stage.
As the system progressed extremely advanced, intrinsically safe, electronic equipment became available.This machine was called a Vibration Spectrum Analyser. At this point an electrical section of the R.C.M. department was created due to the extra workload.
All machinery had a list of specifications when manufactured. These included number and bearing types within the machine. All the specifications were inputted into the Spectrum Analyser software and all new machines such as fans, motors and gearboxes were tested for vibration oscillations and harmonics when brand new. This data was used as the baseline for future monitoring. Any faults in a machine were quickly found and investigated. This sophisticated system, along with oil debris analysis ensured almost no catastrophic failures of equipment and loss of production.
As automation progressed widely in the industry, all ventilation fans, compressors and conveyors were monitored constantly as part of the control and operating system, MINOS, to ensure safe operations.
Selby Superpit 