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Post by John on Aug 19, 2008 12:41:27 GMT -5
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Post by dazbt on Aug 19, 2008 12:57:38 GMT -5
and other areas as well, Scotland's Frances for one. |
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Post by John on Aug 19, 2008 13:07:13 GMT -5
and other areas as well, Scotland's Frances for one. I knew about the Fife coalfield, thats the only place apart from a couple of Welsh pits that I thought it was practiced. |
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Post by Balladeer on Mar 9, 2009 20:58:59 GMT -5
Hello there ........... .......new member here from down in The Forest of Dean.......... a well hidden little place that used to have some mighty impressive collieries all now sadly gone....the last big one closed in 1965 ....but there are still a few small 'Freemines' down here ..... ....Anyways...........I've have had a look in the glossary and have also had a bit of a troll through this very interesting site ..and I have a question... .I've just read a book about the demise of the Scottish Coal fields and there was much talk in there about the 'Horizon Method' of mining......Despite concentrating on how the author described it's operation.......I have to admit to still being completely baffled .... Now then....I understand the business of driving out to the boundaries.....I'm familiar with retreating or advancing longwalls and very familiar with pillars and stalls as I did actually once work in a very small freemine that used that old method ....but this 'horizon ' business has me in the dark (heheheh! Mines , Colllierys..in the dark!! hehheh!Ah well........) ............can one of you talk me through it  ?....Cheers ! |
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Post by shropshirebloke on Mar 10, 2009 3:43:30 GMT -5
I'm no expert but here's my understanding:
The term "horizon mining" doesn't refer to the actual method of coal extraction (long/short wall or bord & pillar) but rather to the layout of main driveages, especially haulage and belt roads.
Conventionally these would be driven "in seam" leading to difficult gradients where seams are steeply inclined or undulating.
With the horizon system main roads are driven horizontally through rock to intersect seams (actually with a slight dip towards the shaft to favour the load outbye).
Roads can be driven on more than one level, arriving at the winding shaft at insets or landings, or alternatively coal would be fed between them to the lowest level via staple shafts to simplify coal handling in the shaft.
Just my five pennorth, I'm sure there are plenty on here with practical experience of the system.
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Post by Balladeer on Mar 10, 2009 6:11:14 GMT -5
Many thanks for coming back.........
The book I have just read is "The Disappearing Scottish Colliery" by Robert S Halliday....
It gets a little bogged down in statictics and a 'professory' sort of manner of facts and figures and 'whyfores/ therefores' etc but overall I found it a good read.........
So....
......Having established what the basic plan of an 'Horizon ' system is........
Why would the system be 'not suited' to a particular mine as it apparently wasn't to the disasterous Rothes Colliery???
In the Forest of Dean the coal measures are (very simplistically put) a 'bowl' of coal with the bowl tilted slightly to wards the south west ......Consequently all the big collieries in the Dean worked coal that was usually 'pitched'.........and some of the pitches were / could be rreasonably steep...............I can imagine if the coal was in a 'level' state then horizon mining would be the way to go but with any kinda of pitch to the coal would there not be continual problems with water lying in the drivages from the 'main' roads towards the coal?
Sorry to ask further details !! just fascinated with coal and the getting of it and always have been !
Many thanks Bob
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Post by Balladeer on Mar 10, 2009 6:15:25 GMT -5
..and also if the coal pitched 'downwards' from the main road would there not be the need for any number of extra haulage underground to haul the tubs etc back up to a main road??? unless these kinda mines would always be working a conveyor system Cheers |
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Post by John on Mar 10, 2009 6:20:47 GMT -5
You've got it!
I was confused at first, but it was used by the old NCB/British Coal in new pits where they were going to work multiple seams too. But was started in steep seam pits like those in Fife where the seams were 1:1.5. and Lancashire where they also had a few steep seams.
As you say, the lower horizon was either slightly inclined to pit bottom or level for loco haulage.
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Post by John on Mar 10, 2009 6:31:13 GMT -5
..and also if the coal pitched 'downwards' from the main road would there not be the need for any number of extra haulage underground to haul the tubs etc back up to a main road??? unless these kinda mines would always be working a conveyor system Cheers I think a lot of the Fife pits where "horizon mining" was done used loco haulage. The coal was transported from the main gate to vertical in seam ore bins to the lower horizon where it was loaded into mine cars and hauled to pit bottom via locos. From what I have been told, loco haulage of mineral was common in the North East coalfields too, I was always used to conveyors to pit bottom or via drift to the main "run of the mine bin" on the surface. |
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inbye
Shotfirer.
Posts: 114
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Post by inbye on Mar 10, 2009 14:32:57 GMT -5
We used the "Horizon" system, in part of Park Mill Colliery, in West Yorks.
If you visualise the coal seams dipping from West to East, (in my neck of the woods, localised faulting exepted) & drive a level roadway in line with the dip, you can see you will intersect a number of different seams, with the road you are driving remaining perfectly level. From the Horizon Mine (at Park Mill) the bords to the different districts would follow the natural dip of the seam. Coal, extracted in the usual way, was then conveyed to storage bunkers at the level of the Horizon Mine & then conveyed by diesel loco & mine cars, to the far end of the Horizon, where it made it's way up to the screens, via a tippler station & drift belt.
This was my understanding of the term & I imagine it would work similar to this at other pits. Hope this helps...
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Post by shropshirebloke on Mar 10, 2009 18:19:11 GMT -5
Just a couple more thoughts:
The idea seems to be to let gravity help as much as possible, faces generally worked up from where they intersected the horizon, so mineral and drainage water would naturally be heading downhill aided by gravity.
This would allow the energy-intensive parts of the process (coal/dirt winding and pumping) to be concentrated at shaft bottom for maximum efficiency.
To show that there's nothing new under the sun, a similar system has been used in lead and tin mining for centuries, with "stopes" following ore veins upwards, the mined ore falling into horizontal roadways, then shot down vertical "ore passes" to the lowest level of the mine and then wound to the surface.
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Post by Balladeer on Mar 11, 2009 6:11:23 GMT -5
Thats a lot clearer now many thanks !
As suggested I guess it would make sense to work 'uphill' from the main road into each seam the main 'horizon' road had cut through.........presumably another horizon road would be driven off the shaft at a deeper level to enable the lower part of the seams to be got at and worked 'downwards' the in the same fashion.
At a small private colliery operating down here in The Dean the one seam the lads are working is pitched so steeply that the coal is loaded off the face which is about 30 yards in length (described as a 'short longwall' by one of the miners!) into a aluminium 'trough' where gravity causes the coal to simply slide down the length of the face to a lower haulage road where a fella is stationed who oversees the filling of the rail tubs......... these are then collected at a suitable place someways back along the road towards the drift in readiness of making up a 'rake' for hauling to the surface...same sorta principle I guess of using gravity to save on haulage .....
Many thanks to all for the explanation! Cheers Bob
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Post by Balladeer on Mar 11, 2009 6:21:05 GMT -5
Sorry to carry on but. .........I still don't understand why this system wouldn't be 'suitable' in some mines???......... .....Given that the colliery company has plenty of cash to spend on developing the mine before serious production is started.........as was the case at Rothes......... how and why might the Horizon system not be suitable ? And...precisely why would a company wish to use this system at all???how does the system perform 'better' than the seemingly very straightforward method of driving roads out to the boundary and retreating / working from there back to the shafts??? With the 'boundary road' method obviously you get to abandon the roads as the face retreats.....thus saving maintenance & pumping etc etc...... ....so why would you want to work an horizon system ?? Cheers |
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Post by John on Mar 11, 2009 7:04:48 GMT -5
I don't think it's to do with using gravity as much as being sensible.
The first pit I worked at, the main roads were all over the place, 1's trunk conveyor road had two drifts along it, the man rider road went down a steep drift from deep hard to piper seam. So the means of rail transport was rope haulage. Men and materials, making both a costly exercise and labour intensive.
Cotgrave my second pit was mostly diesel loco haulage as there weren't any steep inclines that I recall. Gate transport was via mono rail haulage strung from the roof due to a soft floor that a bad habit of lifting!
Another advantage of driving a "horizon" is being able to use "in seam" vertical bunkering systems.
But seeing photos of some of the Fife collieries faces, I think I'd prefer level longwall faces!! Crawling up a gradient of 1:1.5 several times a day for 250 yards doesn't do anything for me!
Plus the extra danger of the chocks sliding down the face, one accident that did happen at one pit in that coalfield.
And, can you imagine the shearer "getting away from you" on it's return trip to the M/G??? It would be traveling at a fair speed by the time it landed in the stable fast end!
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inbye
Shotfirer.
Posts: 114
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Post by inbye on Mar 11, 2009 14:05:14 GMT -5
Don't know about driving uphill from the horizon, all the districts at Park Mill were to the dip. If we'd gone up, we would have been mining spuds, not coal. You could hear the farmers tractor, when the pit was quiet.
The only reason I can think, as to the Horizon method not being suitable, would be if the ground was known to be prone to local faulting..........but I should add, I've no experience in surveying...
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Post by philipford734 on Jun 7, 2010 16:11:10 GMT -5
I worked at several pits in Lancashire that had horizon tunnels. Bold, Cronton, Sutton Manor and Parkside. The seams in West Lancashire dip to the west from 1 in 4 to 1 in 8. It was a successful method of intersecting the seams and transporting coal underground.
The only drawback was at Bold Colliery. When the horizons had been driven the manager was under pressure to get coal out. As soon as they reached the Wigan 4ft seam he opened out and worked coal close to the horizons. This looked good on his CV and he was promoted to another job. The next manager then had a problem with crush on the tunnels. The two tunnels then had re-rips and dinting going on all the time up to the pit closing over 25 years later.
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Post by John on Jun 7, 2010 18:33:28 GMT -5
I've done more reading in the last few years than I ever did during my training at pit.
Inbye, main reason for driving horizon roadways is for haulage, electric and diesel locos can be used from pit bottom to the furthest boundaries of the mine. I've been reading a lot of horizon style collieries use loco haulage of coal. I'll add more later.
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Post by garryo on Dec 22, 2011 10:12:22 GMT -5
Some of the North East pits did indeed use the Horizon mining system. Three reconstructions, Wearmouth and Westoe (both under the sea) and Hawthorn combined mine which linked Eppleton,Elemore and Murton collieries all used this system in conjunction with locomotives. However in all three cases trunk conveyors were later installed.
Hawthorn winding shaft was interesting from the fact it had four skips operating in the shaft. One set operating from the low level and the other set from an intermediate level.
The winders were not friction or tower mounted but both winders were next to each other in the same building.
Some of the older pits in the West of County Durham also used a type of horizon system where a cross measure drift (usually driven slightly to the rise) would be driven from the shaft botton to the farthest point . The dift was usually fitted with an endless rope system.Coal be either conveyed uo to or dropped down to main loading points along the drift.
One colliery I was at, the drift was just under 2miles long until it hit a major fault. Rising from the shaft at 1in 144 and served three main loading points. The endless was about 150hp and the drift was lit all the way along (as per regulations). Full time job lamping up, normally a Saturday job.
Conveyors ran either up or down from the drift to the various districts plus one short staple.
Typically just before closure the NCB removed the endless and put conveyors through to the shaft doing away with about twenty datal hands, then after completion the Area director came along and told the men that the mine had a "long life", six months later closed on economical grounds!
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?....Cheers !