Dirt Tipping - Page 1
- In the beginning the small amount of overburden above the seam of coal at the surface was just scattered to the side as the coal was extracted.
- Irrespective of how the output was raised in the early days none or very little waste material would be extracted usually only sinking strata.
- With the bell pit system once a shaft was abandoned the waste material excavated was cast down the previous shaft and so on therefore most if not all of the discard was thrown back down the pit again.
- As mine shafts became deeper the amount of sinking dirt increased and a pit hill as it was called was created close by and the material tipped in a haphazard fashion but in the same area. Dirt sent out of the mine after coal production had started would only be ripping dirt and other dirt sent out in tubs by colliers who would forfeit wages if their tub was tipped over and found to contain dirt. It is known that constant deliberation of sending dirt and unsaleable coal out of the pit would result in the miner getting sacked.
- Because of the limited amount of dirt being sent out of the mine the dirt tip would remain relatively small and of no general danger. An example of a pit that last over a hundred years is Brinsley where the pit tip now covered in self-set trees and grass and is accepted as being a hillock on which a copse of trees has grown and as in many parts of the country blended into the general lie of the land.
- Pits that were sunk over 150 or before or up to 100 years ago as stated had small tips, however as mines grew in size much bye work would have to be carried out such as dinting or cheeking or back ripping and probably front ripping of dirt to create a larger roadway down that would allow the passage of the coal in wagons or tubs hauled by donkeys or ponies. Prior to this action boys pulling and pushing sledges, boxes and eventually wheeled vehicles had to do so in roadways only at the height of the seam or less following floor lift etc.
- Tips were then made on Greenfield sites as the expansion of the mines increased and no regard was made as to the nature of the underlying strata near the surface such as clay etc or a stream or rise of a spring. All grades of waste were tipped together ranging from large lumps of rock or shale, soft clunch and small coal discard.
- Various methods were adopted as pit heaps grew larger and consideration was given as to efficiency, not efficiency of the way of tipping but efficiency of tipping using as few men as possible and tipping in an area close to the pit top.
- Conical heaps began to appear on the landscape in mining areas as a method of tipping known as McLane was used whereby a container was constantly pulled up a set of rails that were raised periodically and the dirt just tipped over the top creating a heap not unlike a pyramid. In fact the dirt tips at Kirkby Summit in the 1950s were referred to as the 3 pyramids (as per Egypt). Here an early form of restoration was tried.
- Many tips either built by the McLane method or otherwise became prone to spontaneous combustion and steam or acrid smoke was seen issuing from crevices in the tips. The mining companies were not particularly concerned by this, in fact some welcomed the fires as eventually as the fires died out or crept along the tip it was possible to extract red shale the baked hard remnants of the grey shale originally tipped. This had a commercial value and was sold as foundation material for roads etc.
- Unfortunately many accidents occurred due to these heatings and over the years some men have been affected by the acrid smoke and possible inhalation of gas from some of the incomplete combustion of the small coal that had started the fire and propagated it.
- There has been examples of men falling through the surface of the tip where a fire has burnt away material leaving a void under a thin crust on the surface that would collapse when a body weight was put on it. A tragic example I learned about was a child playing (illegally) on the smouldering dirt tip at Ollerton in 1938 fell through the crust into an inferno and was so severely burned that although her father was quick to pull her out suffered in agony from her injuries and died after a few days.
- Other methods of tipping were conveying the waste up the tip by conveyor then bulldozing it over the edge of the tip whilst extending it. The dirt would then cascade down the side of the tip just built creating a very unstable base for future tipping. An example I remember at Teversal where the tip was slowly moving forward over a meadow grass field and rippling the ground in front. It was later found that a bed of clay just below the surface was acting as a slide. This tip eventually collapsed and a slurry pond built on the tip cascaded down and into a small stream leading down to the River in Hardwick Park. Men were brought out of the pit to dig out the stream casting the dirt to each side. However damage to wildlife and flora was done but there had been no risk of danger to animals or people so that episode was closed. A further collapse of a tip allowing another slurry pond to cascade and flood the internal railway line between Teversal and Silverhill collieries occurred and again there was no loss of life or even much damage and the railway line was soon in operation again although it took some weeks before the material had dried out sufficiently to allow one to walk that way without sinking into the slurry.
- Coal production by modern cutter/loading machines such as trepanners and shearers cut into the floor dirt and also the inseam dirt bands added to the problem as all the produce from the coal face had to be sent out of the mine and sorted and washed in the coal preparation plant thus adding to the faster expansion of the dirt tip as previously with hand filling methods much of the dirt was packed into the waste or gobbing behind the coal face and thus remained underground and not sent out of the mine.
- A major disaster happened at Aberfan in South Wales in October 1966. A waste tip built haphazardly by the method of just tipping over the end of a conveyor or otherwise onto the side of the mountain suddenly slipped following a period of heavy rain and cascaded like an avalanche down the steep sided valley smashing a way through several houses and finally almost engulfing a school with thick sludge and other debris and 114 school children plus 14 adults perished. Miners were brought out of the nearby pit and hundreds of them and others toiled with shovels etc whilst some just using their bare hands tried to shift the waste material, but to no avail. A generation and a community had been erased.
- Following this disaster, methods of tipping future refuse were gradually brought in and eventually the Tips Act 1969 and Tipping Rules issued whereby all colliery tips in future had to be deposited in thin layers and compacted either by Euclid load-haul scrapers or load-haul dump trucks delivering dirt to areas where scrapers hauled by bulldozer were used to compact the material. Methods such as using Jubilee side tipping wagons as at Ollerton were dispensed and all the old aerial bucket type tipping removed and as at most pits then dirt bunkers were built enabling dirt from the washery and coal preparation plant to be available at all times for transportation onto the tip sites by the various machines mentioned. These trucks and Euclid machines and their drivers were hired on a contract from firms such as Wimpey or Sheppard Hill to build the tips to proper specifications etc under the watchful eye of the Civil Engineers assisted by the Colliery Surveyor who would survey and plot and update the Tip Plan at least once per year. The Chief Engineer and and his engineers plus the Surface Superintendent.
- All old conical tips had to be lowered and adjusted for area etc and compacted. All other types of tips were re-graded and compacted where possible down to original deposition levels or solid bases.
- All tip banks where slurry ponds were built had boreholes drilled at the sides by George Wimpey for example, and tubes installed and piezometers were issued and Colliery Surveyors and Area Civil Engineers monitored and recorded values periodically where a water table was discovered to note any variation and in particular on over-tipped sites of lagoons. This was as a precaution against possible slurry lagoon bank failures in the future.
- All tips were examined by Civil Engineers and Surveyors for movement etc and various reference lines were established on tips that were being undermined to see what effect subsidence had on the stability of the tip. For example Teversal and Mansfield. A tip had collapsed at Creswell and a road was blocked permanently as it was easier to create and build a new road round it.
- All Surveyors, Surface Superintendents and Civil Engineers on tips were required to attend a Tipping course at Lound Hall where all aspects known at the time for making new tips and ensuring that old tips were made safe were to be enacted.
- All tips that were old, for example at Teversal about 100 years, old plans showing the growth of the tip from various bits of information and proportion of refuse from saleable output where known and the best guesstimated position of a tip at those periods and a series of plans and overlays created. Of course the later years from about 1970 when the Tip Act 1969 came into force yearly positions were plotted from Surveyor’s measurements and from about 1980 the tip plans and volumes were obtained from photos taken by dedicated aeroplane firms on specified flight paths, yearly, to note any specific change. Things to look for were springs or streams that had been over-tipped in the past. Boggy land and marsh or clay pits etc were searched for on old plans of the area before tipping commenced, providing of course these plans were available.
- Many tips were restored as part of the return to Greenfield sites and soil and grass set and trees were planted on a regular basis. Some tips were re-soiled and returned to farmers and crops of barley were set and harvested one year later. Cows and sheep were able to graze on other restored tips. North Notts Area of the NCB was the first to begin restoration of this nature as part of the legislation being developed from information supplied at Teversal Colliery in the late 1960s. The Inspectors of Mines & Quarries and Civil Engineers and Surveyors made Teversal their base to instigate the new rules and regulations and numerous trials and subsidence lines etc were set out. Being Senior Assistant Surveyor at that time a fair amount of the work was done by me whilst my boss the Surveyor attended the meetings and discussions. Occasionally I attended also.
- Mulched grass was more or less blasted onto the sides of the semi-flattened tip sides at Kirkby Summit but the experiment failed as the grass refused to grow on bare shale. It was then realised that some sub-soil would be needed to allow this to happen and the tips hav been grassed by this method successfully. Trees have also been planted and have flourished but again in thee early days thousands of young sapling trees were just pushed into the tip waste without any preparation and they just withered away. Trees planted later in properly constructed holes with a base of loam or soil etc enabling water to reach the roots flourished and the results are there to be seen.
- Many tips have since been excavated and all the small coal that was discarded in the past has been recovered, cleaned and sold to prospective buyers, some of course being the Power Generators. The tips then have been restored and grassed and thousands of trees planted and many have been sold to the County Council for a peppercorn fee of £1 and country parks and walks etc have been created. When these trees have matured they will create lovely woodland areas as secure havens for wildlife and for future generations of our families to enjoy. Some tips have been adapted for golf courses thereby assisting further in the activity side of life. Most tips in our region are now well established in their new role and blend well into the existing landscape. Future generations will accept the views assuming that they are natural hills and forests and unless told otherwise will have no idea that they were once dirty grey colliery spoil heaps that were a blot on the landscape. This was an unfortunate by-product of our once great mining industry. Our country developed the mines as the Industrial Revolution gathered pace and surely as the mines have completely gone in the UK so will the eyesores. Opencast mining has taken the place of the deep mining of coal and some of these sites have been on past dirt tip areas and once the coal has been excavated and the different overburden strata replaced restoration is completed and once again two problems have been solved, possible instability of a tipping area and future regeneration of the land.
- Once again though a problem had occurred in South Yorkshire where a dirt tip at privately owned Hatfield colliery had slumped and undershot the adjacent railway lifting and twisting the lines into contorted shapes. The line had to closed and coal traffic and passenger services stopped. Passengers had to transported then by bus. The problem was resolved but the compensation for the closure of the line and the cost to the company for the transportation of passengers plus the tip removal and then its stability was probably very substantial, possibly to the breaking point of the colliery closing.
Hatfield Tip Slide
- Thoresby colliery at Edwinstowe in Nottinghamshire had a great problem with the ratio of coal to dirt. The vend as it is known has been in favour of dirt so the present dirt tipping area grew much quicker than was planned and tipping room was at a premium. An application to the Town & Country Planning department for the area was made regarding the possibility of tipping on the already restored area facing the A6075 road that passes by the colliery. I would suggest that that was a very awkward situation to be in and took some time to answer as all aspects had to be taken into consideration. Lagoon space was also critical as slurry discard from the washery plant needed to be placed somewhere to dry out as it cannot be spread whilst wet. Tipping in an area towards the village housing in was not feasible. I felt that UK Coal mining side of the company higher management would have been waiting in trepidation on the outcome. A large fissure at the surface caused by subsidence from a retreat panel in Deep Soft seam at Thoresby Colliery resulted in the A614 main trunk road to be closed for several weeks whilst the fissure was filled and the road repaired. Again I think that compensation claims would have arrived at the UK Coal office over this as long detours of about 11 miles had to be made by all traffic particularly heavy goods vehicles wishing to use that route during that period. UK Coal could claim insolvency as it has been muted that they had a cash flow problem and the workforce attempting to make sure that their pay and pensions were secure. This series of circumstances was probably the last straw on the camel’s back as two further panels were planned to undermine the road but the mine closed in July 2015. This was the last working mine in Nottinghamshire, a county that has produced coal for over a thousand years.