Stull or Stemple

[bograt]

Unfortunately the purpose of this exploration was to investigate and restore water to the pumps supplying Cavendish Mill, so after exploration they blew the water gates and flooded the lot!!. There must be a really interesting perched water table in that area, John called it a 'saddle' between Wardlow Mires dip and Middleton Dale.
Apparently the water gates were incredibly well engineered stone dams blocking the water off partway down the shaft, blowing them allowed water into the lower workings where the pumps were located.

Not that there is a water "table" in limestone, presumably the workings are in rock with very little faulting, so there is nowhere for the water to escape, except spilling over the top.

Mike

I suspect that the water was perched above an impervious layer, such as Tuff or Lava, the bedding in that region is complicated.
But I bow to your obvious superior knowledge of Peak District geology  :bow: :bow:.

 

[Amy]

To throw in some American to the mix, i have never heard of stull but we use the term stemple when using a plank of wood to rig on; ex crack and crevice and can wedge say a 4x4 to rig / redirect, so can lift up directly out of the vertical crack, so this thread is interesting to learn new ways such terms are used!

 

[mikem]

The water probably is perched above an impervious layer, it would still be expected to spill out sideways through the surrounding limestone, alternatively it might be trapped in an impervious syncline, but that would need to be bowl shaped to contain the water, so I think it more likely that they mined into rock where any outflow is so immature that it can't compete with the flow that is now directed into the workings.

Water "tables" exist in permeable substrates, such as chalk or soil; in limestone it fills up the available space between the rock.

Mike

 

[Brains]

Found another term I am not familiar with from a mining context
"Pentice" This seems to be a section of covered level in a stope or shaft to protect the level from falling debris. The only image I have seen seems to show stemples/stulls boarded over and bunded with deads, but the wiktionary entry implies solid rock?

witionary: "(mining) An unexcavated portion of a shaftway, intended to afford protection from falling debris to workers at the bottom of the shaft during certain stages of mining."

https://www.facebook.com/TheVictorianHistoricalMineChasers/photos/a.882574091797194.1073741831.868378596550077/979833752071227/?type=3&theater

 

[royfellows]

I believe its "Penthouse", there is possibly a corruption of the word?

 

[Brains]

I can see how it may have been corrupted, but the meaning still seems a bit odd to me. Also seen the term pentice defined as a projecting roof portion to give shelter. There do seem to be a lot of odd words around the mining world!

pentice ?(plural pentices)

    An extension of a building's roof and the protected area beneath. An appentice.
    A covered walkway.
    (mining) An unexcavated portion of a shaftway, intended to afford protection from falling debris to workers at the bottom of the shaft during certain stages of mining.