1992 - Page 9

Inflatable Balloon Borehole Liner

Ken Hartwell, Area Tunnelling Team Chargeman for Nottinghamshire Group invented an inflatable balloon borehole liner for use with inter-seam borehole drilled for ventilation. After the pilot hole has been drilled a large dia bit up to 5’ 0” (1.5m) to 8’ 0” (2.4m) dia is reamed back up the hole to the starting horizon.

On numerous occasions falls have occurred when strata has peeled away from the side of the hole and either blocked the hole or fallen to the bottom.

Great difficulty was previously experienced in filling the cavities and making the hole safe. Now the inflatable liner can be lowered to just below the cavity and once in position inflated to seal the hole. Grout is then pumped into the cavity. Once the grout is set the balloon liner is deflated and if necessary the procedure repeated at another cavity. A special protective shield above the liner protects it from falls above and a pipe through the liner ensures that ventilation is continued whilst operations are in progress.

Ken was awarded £750 from the Nottinghamshire Awards Panel who forwarded the idea to UKASS for nationwide recognition. I had great affiliation with Ken as it was necessary for him to be in constant touch with the Colliery Surveyor to report on progress of a project or to seek information on the job in hand. Particularly at Ollerton where we were the first to ream out a hole using a Robbins Raise drill so that a 1,000 tonne vertical bunker could be constructed and on various other mining projects such as solid drivages, junctions and special work etc. Ken would call in to see me quite frequently and would ring through to Welbeck to clock off as that was his base colliery for some years.

Job Shops

Job Shops set up by British Coal Enterprise in 1987 were helping to find work for many of our local miners thrown out of work by pit closures or manpower reductions.

Price Of Coal Specified

The UK power stations requested that British Coal produce coal for them at an operating cost of £1.30 per gigajoule or less. The contract for 1991-1992 was 70m tonnes.

The UDM Miner leaflet bulletin update Nov 1992 stated that the UDM was in the High Court again on 19th Nov 1992 presenting a case against British Coal but also against the Secretary of State for Trade and Industry. The UDMs lawyers Hopkin and Sons were seeking specific orders that Cotgrave, Silverhill and Trentham resume working and the men to get a mine workers average wage and not the guaranteed wage during the 90 days consultative period.

British Coal Told Not To Close Any Pits

British Coal had to give oral evidence to the Trade and Industry committee, regarding the collieries in question.

On 21st December 1992 in the Queens Bench Division of the High Court, British Coal was told not to close any of the 10 collieries. The decisions made on 13th October were unlawful but rendered ineffective on 19th October.

Boyds Appointed to Report on Pits

The President of the Board of Trade, Michael Heseltine appointed Boyds, (American) International Mining Consultants, on 23rd December 1992, to report on the 10 pits in accordance with the views expressed by Lord Justice Glidewell.

Pay Rates

Pay rates for Under-officials:

• Colliery Overmen per week £333.00
• Overmen £323.50
• Deputy Gr I £314.10
• Deputy Gr II £304.50.

Weekend bonus for:

• Overmen £12.00
• Deputies £11.30 per shift.

Mid week overtime for:

• Overmen - shift £11.00
• shift £22.00
• full shift £44.00
• Deputies - shift £10.35
• shift £20.75
• full shift £41.50

Service bonus at year end

• 2 to 4 years £20
• 5 to 14 years £30
• 15 to 24 years £50
• Over 25 years service £70

For part time Rescue Brigades men

• Retaining fee of £80 increased to £100
• Outside hours £6.00 increased to £12.00
• Attending an incident £1.50 increased to £3.50
• Hourly rate £2.50 increased to £6.00
• Minimum call out fee £6.75 increased to £15.50

Prevention Of Inrushes

The Health and Safety Executive (H and SE) issued an ACOP on the Prevention of Inrushes and Coal Mines (Owners Operating Rules) to ensure that the existing good practice in coal mining was maintained after privatisation.

British Coal issued a Code of Practice 1992, for the Detection, Monitoring, Handling and Disposal of Low Specific Activity Pipescale and Sludges Resulting from Underground Strata Dewatering Processes.