Pumps

Peter Burgess

New member
There is a dig going on in Sussex at the moment. It is a shaft into a limestone mine, that as far as we can tell was not drained artificially. However, there is now a serious water problem. We need to think of a way to pump the water out. Last weekend, baling with buckets did not reduce the water level significantly. The last chance to see what is down there relies on getting the water out. The water is effectively liquid mud. The shaft depth is something like 40 ft. Does anyone have any experience of pumping filthy water from the bottom of a shaft, the base of which is full of grit, stones, clay, and bits of old wood? Any good ideas I will pass on to the group.

For the background to the dig and some pictures, see http://www.kurg.org.uk/ under the 'work in progress' link.



 
H

hoehlenforscher

Guest
Not really tried with real dirty water. We were digging a 40m shaft in souther germany and the bottom 3-4 feet or so would always fill with water between digs (generally an annual week long blitzkrieg affair). We tried running large bore push pumps to raise the water out of the shaft via collapseable firemans hoses but failed miserably to move the water, even using staging pumps eavery 10 metres. In desparation we tried a ickle 12v garden pond pump on the surface with a garden hose lowered into the bottom of the shaft and it worked wonderfully. Took a day of so to empty the shaft but hey, its better than working waist deep in water to dig on eht shaft floor! :cry:
 

Brains

Well-known member
For anything other than clean water a semi trash pump would be needed - this will do gravel quite nicely, a full on trash pump will do bricks, but also cavers, wellies, crowbars...
My mate got one for our swallet dig and it will happily do upto about 50mm lumps. Runs on petrol so there are issues there. Require additional suction hose and delivery hose. I will ask him the specs, pricing etc...
 

Peter Burgess

New member
Thanks. I think KURG are rich. They are well clued up on this sort of stuff, but I reckon you can't beat advice from someone who has been there before.

 

Brains

Well-known member
The pump we have is a petrol Clarke one from Machine Mart and was about £330 inc VAT. It will do upto 700L per min and will lift a head of 23m. Published specs say 20mm lumps, but I am sure I have seen bigger come out of it!
Suction hose can be pricey as well, butfind who hires it out to contractors, they WILL have pallets of damaged hose (driven over by plant) going very cheap. DO NOT buy "O" rings as official spares, they are the same as the old hoover drive belts and cost pennies not pounds. delivery hose can be lay flat, what ever is cheapest. It will just adios all manner of cac!
 

Brains

Well-known member
http://www.machinemart.co.uk/product.asp?p=051011090&r=2159&g=122

This looks very like the beasty, although specs seem a bit better than our one!
 

AndyF

New member
Rather than buy a petrol pump, you are better off buying a seperate generator and pump. You can use the geny for other things then....

Buy a dirty water 110 volt pump. MUST be dirty water rated or it WILL break. (Cast metal impeller rather than plastic)

Make sure you get one with sufficient lift, you probaly need a two-stage for 40ft. Remember it pumps slower the higher the lift, and you have to allow for the depth to the bottom of the water not the surface

like this one (although this isn't dirty water rated)

http://www.machinemart.co.uk/product.asp?p=051011065

We've got one but only 7m lift, used it lots in Waterways. Very effective.

Draper brand are good. The Clarkes are good but more expensive for two-stage




 
D

Deeply Mendippy

Guest
I know nothing about pumps but I do live fairly close to Burwash so if you need an extra body next time to help with some of the menial work then let me know.
 

Peter Burgess

New member
I drive past a pub called "The Piltdown Man" in Piltdown, on the way to the dig, with a picture of said missing link on the pub sign. And when I first saw it I thought it was there to encourage cavers in, by illustrating the type of client they wanted. ;)

Anyway, back to the pumps......


 

AndyF

New member
You have to use a pump at the bottom, you can't use one at the surface as you can't suck water up more than 32 feet.

Is this mine in Archer Wood?  Should be impressive if you can get in, though you may have a lot of pumping to do!


 

Peter Burgess

New member
Archer Wood dig was abandoned many years ago - similar problem, but there the mine was originally drained with a waterwheel-powered pump, so the chance of getting into anything was pretty low. This latest site was almost certainly a much smaller affair. Compare the wooden shaft lining the guys were using at Archer Wood with the steel scaffold frame stuff being used now, and you can see the team have moved on, certainly into the 20thC if not the 21st. (Sorry guys, no offence! - it's all very impressive really.)
 

AndyF

New member
Nice pics, I hope you haven't hit groundwater, or you'll have a big pumping operation on your hands.

A submersable should give you a chance, they shift a fierce amount of water.....
 

Peter Burgess

New member
My hunch is that we have following scenario:

The dig has reached the roof level of some chambers or galleries.

Originally the miners dug out the limestone, and coped with a small influx of groundwater by baling, maybe each morning ? When the workings were finished, the workings gradually filled up with water. Or there may have been a storm that flooded the mine, and they didn't have the means to get the water out quickly.

We can only find out what there is by pumping out this water, obviously. If my hunch is correct, the true influx of water is low, and what we are seeing is the static water in the flooded chambers/ galleries topping up the level in the shaft. It's a bit like pumping out a swimming pool with a small spring feeding it. Sub Brit had a similar challenge a year or so back when they pumped out a totally flooded cold-war bunker, long enough to photograph and record it.

In order to get the most water out, we need to dig the floor of the shaft down as deep as possible to maximise the amount by which we can lower the water level. Not a pleasant task. :yucky:

My guess is we are now at or slightly below river level, but the influx of water may be slow and manageable.
 

Peter Burgess

New member
All comments passed on and acknowledged. The group will try to use a petrol-driven pump they already have, with a special 40 ft long exhaust chimney. Let's see if it copes with all the mud. :(
 

SamT

Moderator
Just had a thought - if anyone ever needs to pump in stages and therefore need header staging tanks. Try using a "ton bag" i.e. those things that builders deliver a ton of sand in.

the four corner loops can be strung up and the bag even suspended in needs be, given sufficient anchors.
Lined with a poly sheet.
Can be rolled up - dead light - should easily take the weight - will mould to the passage walls if need be.

Viola - the perfect underground water tank.
 

paul

Moderator
SamT said:
Viola - the perfect underground water tank.

Hmm - I don't see how a wooden musical instrument would be ideal as a water tank...  ;)

You're right abou tthe "ton bag" - plus I saw one in White Scar laid on its side with the top two corners suspended from above, being used as some sort of shelter in a dig.
 
Top