Given that the E-G incline seems to have been completed in October 1937, I'd hazard a guess that it was the start of the war that restricted the connection of the Oakeley 'Z' chambers to the 'Cwmorthin' 'Z' chambers.

The bit that slightly confuses me is that although chamber Z47 seems to sit immediately below the BVI, it does not appear to have been roofed up to connect to the lwm. Assuming G floor sloped down to Chamber 1 West at that point, driving the roofing shaft up to meet the incline would remove the need to have two pumps.

Of course... if you happened to be working in Z47, then having the BVI draining down into the top of the chamber might not be considered the best of ideas, so perhaps the connection would only have been made once the chamber had been worked completely?

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Given that the E-G incline seems to have been completed in October 1937, I'd hazard a guess that it was the start of the war that restricted the connection of the Oakeley 'Z' chambers to the 'Cwmorthin' 'Z' chambers.

The bit that slightly confuses me is that although chamber Z47 seems to sit immediately below the BVI, it does not appear to have been roofed up to connect to the lwm. Assuming G floor sloped down to Chamber 1 West at that point, driving the roofing shaft up to meet the incline would remove the need to have two pumps.

Of course... if you happened to be working in Z47, then having the BVI draining down into the top of the chamber might not be considered the best of ideas, so perhaps the connection would only have been made once the chamber had been worked completely?

Not sure on the numbering without a map but the furthest worked Z chamber does not get as far as under the BVI, it falls short by a few hundred feet I reckon 🙂

Not sure on the numbering without a map but the furthest worked Z chamber does not get as far as under the BVI, it falls short by a few hundred feet I reckon 🙂

Tsk tsk tsk!

There are three / four chambers on G floor accesssed from the E-G incline in Chamber 1 West: these are Z46 to Z49, with the incline coming down in Z48.

Z47 is underneath the BVI and Z46 is (mostly) under Chamber 1 East - there is then the gap to Z44, the last of the Oakeley G floor chambers, which is roofed up to Chamber 4 East (this is where the water drains down to). This is Z44, looking upwards:

🔗Cwmorthin-Slate-Mine-19-02-2006-Image-013[linkphoto]Cwmorthin-Slate-Mine-19-02-2006-Image-013[/linkphoto][/link]

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ahhh, it's those flooded ones you're on about, now I understand...

Might have to pump them out and go for a look at some point. Could probably do it as a siphon when the water is down to Oakeley H, but would need a fair length of pipe!

ahhh, it's those flooded ones you're on about, now I understand...

Might have to pump them out and go for a look at some point. Could probably do it as a siphon when the water is down to Oakeley H, but would need a fair length of pipe!

You do have some interesting ideas!

If I get bored sometime, I might try and work out the volume of water we're talking about and compare that to the capacity of a reasonable pump to see quite how mad such an idea is...

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Siphon mate. far easier.

Wouldn't take long to pump, hopefully the chambers might still have air space, fissure/crack depending :D

The problem with a convential pump is the 90' lift, you'd need a big'un for that. We could hire some big diesel thing and leave it going for a couple of days but the problem then is terrible fumes and getting it down the BVI in the first place.

Regarding the incline, I did say (in the earlier quote) "It was intended to sink in chamber 1 west, work east and west, and roof up to the original Back Vein incline from below." The original back Vein Incline could then have been extended down to G, removing the need for the auxilary incline. As it was chambers on G were never fully developed and the roofing back up not carried out.

A similar process had been carried out on several occasions at the eastern end of Oakeley when it had become necessary to extend the main K inclines (K2 and K3) to deeper floors. this method enable the main incline to be kept in use without being congested by the sinking process. Only when the roofing up breakthrough ocurred would traffic be affected.

I did do an approximate calculation once for the pumping capacity necessary at the eastern end to lower the water level throughout the mine. Does anyone know/has heard what pumping plant McAlpines are actually using to lower the level to H on occasions ? Given the inflow of water during most of the year, I guess it is only effective in summer. I imaging they do it to get access to the reserves in the walls at the eastern end - the best slate is/was there which is why the previous company concentrated their efforts there as well.

Graham

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I understand the pumps are very substantial. There are three of them at different heights, and combined they fill a lorry...

I'm hoping they might drain to K floor one day...

I've been trying to work out the positions of some of the 1980s pictures: presumably the work in the pit at Oakeley is the reason the pumping has continued.

The 80s pictures show workings around the 'Arches Inclines' descending down below G floor and presumably now the work is continuing somewhere on or around H. Can anyone shed any light on the approximate width of the face that's being worked compared to the location of the original chambers?

I'd assume that as the working face would be chasing the vein downwards, then there must come a point when the cost of removing the overburden starts to outweigh the value of slate that's won.

This is one of Grahami's pictures, which shows Chamber A1 on the left and the remains of the archway on G to the right.

🔗Oakeley-in-the-1980s-Image-024[linkphoto]Oakeley-in-the-1980s-Image-024[/linkphoto][/link]

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Hmm, I suspect H will have to wait. depending on the water level when you were there, I'm assuming until you tell me otherwise that it's now well on it's way back up again. At ch34 it was probably about 10' below H, and several chamber east (where the rustic steps drop into the water) it was about 3' down. So I guess all the way over to the far end the level will be probably mostly submerged, maybe not entirely, but my the time we mobilise ourselves down there it will be...

I think the water when they're pumping is usually about 10' below H? I wonder what level that translates to in the pit?

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Hi

You can get an idea from the relative floor heights at Chamber 38 in the west and Chamber A5 in the east as follows (I've rounded the figures):
Floor Ch.38 Ch.A5
DE 832ft. 801ft.
F 793ft. 769ft.
G 754ft. 726ft.
H 703ft. 670ft.
I 619ft.

As you can see most of the floors rise about 30ft from east to west.

Graham

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