In the early 80's I was Unit Mech Eng at Annesley (I have worked at many of the Nottinghamshire collieries). Annesley held a special appeal for me as it was the pit where I learnt my trade, and also where I can trace my family history back to when it was sunk in 1863.
At some stage it was ventilated by furnaces (cupola's), then by steam driven fans (early 1900's ) and later by electrically driven fans. The shafts were deepened late 1920's/ early thirties to the deep soft level from ?? level, but, unfortunately, the shafts were left with a slight "dogleg" in them. This resulted in the occasional scraping of the brick linings of the shafts. Over time, the method adopted to overcome this problem was:-
- to restrain the guide ropes in pit bottom with brass shoes so that the cages "trajectory" was such that it passed through the dogleg area 'centrally'
- to nibble away at the brick lining to give more clearance. This was still the case when I was doing my shaftwork training in the early 70's, When I was later to return as UME I quickly tired of this continual problem which was by now also aggravated by the ingress of water through leakey cast iron tubbing joints, and decided to strip out the brickwork to expose the offending leakey joints and progressively work my way through the dogleg area.
My job moved me on before I could complete the task. I am now long since retired.
The reason I write this to you is this, what was the purpose of the brick lining? Is it just another example of oh, we have always done it that way, add infinitum. I am increasingly convinced it would have been used to give protection to the tubbing from the sulphur fumes from the furnaces used for ventilating the mine.
However, the mine was no longer being ventilated by furnaces, so I now ask myself, "was the brickwork necessary at all"??? Should I have removed all the brickwork lining throughout the shaft and thus, incidentally increased the clearances and ventilation at the mine.
Another thing that still puzzles me, if this theory is correct, is why the downcast shaft was similarly brick lined, and no fumes passed through it. The removal of the brickwork would have added 2 feet to the diameter of each shaft. Would you, or anyone on your site, have views on this? Purely academic as the pit shut 10 years or so ago and the shafts are filled and capped.
The pit was sunk in 1863 -1865 with both shafts at 13 feet (4m) dia and cast iron tubbing was installed through 131 yards (120m) of the water-bearing Bunter sandstone. A furnace was built at the base of the Upcast shaft at Top Hard horizon. The shafts were deepened in 1914 from 500m to 625m and 485m to 615m to Deep Soft. During the 1921 strike the furnace was extinguished.
Unfortunately due to the cooling down in the shaft the tubbing began to leak and the pit bottom was flooded to 6 feet (1.8m) deep completely wrecking the square work roadways so much so that after pumping out the water and plugging the leaks in the shaft all the roadways affected had to be re-ripped and arches set. It was then decided to put a layer of bricks in the shafts to stop any further leaking but of course narrowed same. A steam driven fan at the surface of the Upcast shaft was installed whilst the pit was stood for some weeks.
The bottom deepening was at 17 feet (5.2m) dia. In later years it was decide to widen the shaft in the 13 feet (4m) length above to create better ventilation, a slow and difficult process as the shaft down time was restricted. However near the Top Hard pit bottom gas was found to be escaping into the shaft from an unknown source. This was excavated in 1989 to reveal some old workings that were not plotted on the Working Plan. With permission from the HMI it was sealed after attempts to explore were thwarted.
As you rightly point out there appeared to be a kink in the shaft from the top part dia to the deeper one. But were the guide ropes etc pulled across to accommodate the changes re the bricking and in doing so caused the problem of scraping at speed through the shaft? Only a suggestion but could explain some of the problem.
A connection was made through to Bentinck and the coal was conveyed then by various conveyors and exited via the Bentinck 1in4 surface drift into the Washery/Coal prep plant and the bunker for rail-borne transport. Coal turning then ceased at Annesley.
Trusting this information will explain some of your queries.