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Post by colly0410 on Mar 18, 2015 18:06:52 GMT -5
At what depth (approximately) would it be more economic to sink a shaft than head a drift from the surface? Advantages & disadvantages of each.
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Post by John on Mar 19, 2015 5:56:07 GMT -5
At what depth (approximately) would it be more economic to sink a shaft than head a drift from the surface? Advantages & disadvantages of each. In coal I doubt depth would be any problem Steve, just look back at the collieries that had drifts in the UK, other than those on the "crop". Bestwood, driven by private enterprise, Selby, NCB. Even the sinking of a drift would be easier compared with a shaft, conveyor against kibble, plus you could sink a drift using a Dosco or similar machine and get greater advance rates.
Now in deeper minerals length would be the problem, take Boulby, it would have been a very long drift, but on the plus side, no bottlenecks like shafts, so continuous transport. Lots of pluses for drifts.
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Post by snowy on Apr 9, 2015 13:22:53 GMT -5
Surley it would be more cost effective to use Drifts the mineral can be got out quicker and cheaper
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Post by John on Apr 9, 2015 16:53:24 GMT -5
Surley it would be more cost effective to use Drifts the mineral can be got out quicker and cheaper I'm sure I posted a link to the Selby Complex on the main coaling drift transport system, if you do a search you should find it, but basically, Selby had a 7000HP DC variable speed Cable Belt, not sure if the paper gave it's cost, but was a few million. The gear box had to be designed especially for the drift due to the length. I doubt private enterprise would have driven the two drifts due to initial cost and long term payback costs.
Drifts are the ideal medium for maximum production, the only limitation is size and speed of the conveyor, I doubt on long steep runs standard belts would work, hence Selby using a Cable Belt, I may be wrong, I'm not a fitter.
But also in very deep mines like some of the Lancashire Collieries were, over 880 yards, work out the length at say 30 degree incline, you'd be out of your boundary at the bottom. The only deep colliery I recall having a drift was Bestwood just north of Nottingham, it was fairly steep, but I'm fairly sure it only went to the Top Hard seam. Just thought, Bentinck near Mansfield had a drift, not sure of it's depth or length, I'll see if I have any info on it.
But Boulby or even the proposed potash mine near Whitby, being a few thousand feet below the surface, those drifts would be several miles long. I'm not even sure if you could use a CM to drive a drift at the angles required.
When I was at Angus Place, we had a crew using our old Lee Norse to drive the driveage and start the bottom of the new drift for the new high speed belts. It didn't get too far up before it had to be chained to stop it sliding back down the stub heading. The drift was abandoned for a while as the budget ran out. The drifts at Angus Place were about 35 degree inclines, depth from surface to pit bottom was around 700 feet, I don't recall the length of the two drifts off hand, but walking up them sure made the heart beat heavy!!
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Post by bulwellbrian on Apr 10, 2015 4:51:05 GMT -5
The Lancaster Drift at Bestwood only went to the High Main seam. The NCB put in drifts at Bentinck and Kirkby. I don't think there was a drift at Mansfield but I could be wrong.
I am fairly sure that High Moor, Oxcroft and Arkwright were drift mines.
I also think that a drift was put in at Silverdale in North Staffordshire. All this is from memory Point of Ayr in North Wales may also have had a drift.
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Post by John on Apr 10, 2015 5:19:47 GMT -5
The Lancaster Drift at Bestwood only went to the High Main seam. The NCB put in drifts at Bentinck and Kirkby. I don't think there was a drift at Mansfield but I could be wrong. I am fairly sure that High Moor, Oxcroft and Arkwright were drift mines. I also think that a drift was put in at Silverdale in North Staffordshire. All this is from memory Point of Ayr in North Wales may also have had a drift.
Any idea of lengths and depths Brian??
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Post by bulwellbrian on Apr 10, 2015 12:38:32 GMT -5
Sorry John, I have no idea. The Bentinck drift went to the Blackshale and was sunk at the time of concentrating Brookhill output to Bentinck. Later Annesley output was concentrated there as well.
Kirkby drift was sunk at about the same time but to shallower seams and took over the output of Langton. I was working at the Lab at the time about 45 years ago but all this is from memory.
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Post by John on Apr 13, 2015 10:18:42 GMT -5
Here's some info regarding the Selby Cable Belt drift conveyor. 14.923Km long. Total lift from seam to surface 990M. 1830tph capacity. speed 7.62 m/s also remembering the conveyor speed was adjustable from zero to that top speed. Belt was 1050mm wide. Total installed power 8750Kw. Power at full speed was 8173Kw.
Again, not sure how much of the 14.923Km was actual drift and/or continuous along the seam to the outbye bunker, but another set of figures I found state two drifts were driven 12.2Km, which would indicate the Cable Belt was installed on the flat for over 2.7Km .
Remember this belt was carrying 10 million tonnes per year when it was in operation, from several mines and I think 10 faces plus developments.
No idea of the cost of driving the two drifts, but would hazard a guess that most of the shafts at each of the pits in the complex were far cheaper to sink and install.
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Post by dazbt on Apr 13, 2015 11:56:51 GMT -5
Here's some info regarding the Selby Cable Belt drift conveyor. 14.923Km long. Total lift from seam to surface 990M. 1830tph capacity. speed 7.62 m/s also remembering the conveyor speed was adjustable from zero to that top speed. Belt was 1050mm wide. Total installed power 8750Kw. Power at full speed was 8173Kw.
Again, not sure how much of the 14.923Km was actual drift and/or continuous along the seam to the outbye bunker, but another set of figures I found state two drifts were driven 12.2Km, which would indicate the Cable Belt was installed on the flat for over 2.7Km .
Remember this belt was carrying 10 million tonnes per year when it was in operation, from several mines and I think 10 faces plus developments.
No idea of the cost of driving the two drifts, but would hazard a guess that most of the shafts at each of the pits in the complex were far cheaper to sink and install.
Don't forget that there was a faster, wider more efficient conveyor in the adjacent drift at Selby the Anderson Strathclyde steelcord belt
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Post by John on Apr 13, 2015 12:50:56 GMT -5
I wasn't aware what the south drift was installed with Daz, I assumed it would have been another Cable Belt. I did a search and found the same company had listed the Anderson's Engineers paper on the south drift belt.www.saimh.co.za/beltcon/beltcon2/paper212.html
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Post by Wheldale on Apr 15, 2015 6:57:57 GMT -5
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Post by colly0410 on Jan 12, 2016 9:13:38 GMT -5
Moorgreen had a drift from surface to the Waterloo seam in 1968/69. Coal came up by a cable belt & materiel down by direct rope haulage. Manriding was via the piper seam shaft inset/landing (about 3/4 way down upcast shaft) then a manriding belt up a drift to the Waterloo seam..
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Post by smshogun on Mar 8, 2018 22:06:05 GMT -5
Moorgreen and Pye Hill had drifts driven to coaling levels retrospectively.
Advantages:
Another means of egress and a walkable one requiring no emergency winder activation in any power outage. Much quicker movement of coal and it could go straight into any prep plant without any other mechanical handling or loading. Increased airflow to older mines with multiple seams worked, or working where older shafts could not cope with airflow demand, or future demand due to much longer distances from the shafts to workings. Cheaper that driving shafts, or enlarging existing shafts.
Disadvantages:
Ingress of people such as children and/or vermin or other unwanted animals. Not as secure as shafts as many were not adequately fenced off. Freezing up at higher/shallower levels from natural ground water ingress forming stalagmites and stalactites, and freezing floors leading to accidents.
Depends on your view?
Men riding out of the mine on them.
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Post by John on Mar 9, 2018 13:38:47 GMT -5
Moorgreen and Pye Hill had drifts driven to coaling levels retrospectively.
Advantages:
Another means of egress and a walkable one requiring no emergency winder activation in any power outage. Much quicker movement of coal and it could go straight into any prep plant without any other mechanical handling or loading. Increased airflow to older mines with multiple seams worked, or working where older shafts could not cope with airflow demand, or future demand due to much longer distances from the shafts to workings. Cheaper that driving shafts, or enlarging existing shafts.
Disadvantages:
Ingress of people such as children and/or vermin or other unwanted animals. Not as secure as shafts as many were not adequately fenced off. Freezing up at higher/shallower levels from natural ground water ingress forming stalagmites and stalactites, and freezing floors leading to accidents.
Depends on your view?
Men riding out of the mine on them. BG's Marblaegis Mine had the icing problem at the top of the drift in winter. I got a call to a breakdown one night shift on the surface plant, we only operated on nights with one elec, one fitter and one diesel fitter. I borrowed the Mine Foremans Landrover, arrived at drift bottome changed into 4wd low range as per the Mangers transport rules, and started up the drift, I was almost at the top when I hit ice, lost traction and got hooked onto the drift belt. I left it there and repaired the breakdown, then managed to frr the Landrover from the belt. Checked it hadn't put the belt out of alignment, then made my way back inbye. Mine Foreman went out and spread salt on the iced drift. Was common in winter.
I recall one real bad winter at Boulby Mine, No2 shaft, the manriding/supplies shaft was closed for normal manriding due to dangerous ice build up in the shaft. Shaft men had been working on it, but had a lot to get free, so it was designated an emergency egress only until it was cleared. Well, it cleared itself one backshift, huge chunk broke off, wiped out the steel work at shaft bottom. It was decided to recap the rope on the cage that was at pit bottom at the time, just as a safety measure. Mean time it was a 25 man limit until the repair work was completed.
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