Capping some holes near Eldon Quarry - DCA Project
- Thread starter Pete K
- Start date
pwhole
Well-known member
What a wonderful smooth finish - I was worried I'd left you in the lurch for today but it looks like there were plenty of staff in the end! Had Saturday's cast gone off by the time you got back? It hammered it down for ten mins here in the evening and I was worried it might be full of small craters by the morning!
Pete K
Well-known member
Friday's concrete had gone off fine with a rustic textured feel to it. No cratering from rain and we were able to walk on it yesterday. Fingers crossed the tarp survived on the second hole long enough to keep the rain off. I'll pop back in a few days with the steel lids and we'll see.
Pete K
Well-known member
Do you recon just placing the 40kg steel plates over the holes is enough?
I worry if I drill them and place them on bolts in the concrete that the threads on the bolts will just get mashed up with the heavy lid banging against them each time it is lifted on and off. I'm thinking of drilling some holes to tie a couple of rope handles on and just plonking it on.
I suppose an alternative would be to get a bit of steel angle or square tube and bolt it into the concrete across the steel plate. Might stop it slowly walking off the shaft with cows standing on it. Hmmm.
Neither hole will see many visits so effort for lid construction is really not a priority.
I worry if I drill them and place them on bolts in the concrete that the threads on the bolts will just get mashed up with the heavy lid banging against them each time it is lifted on and off. I'm thinking of drilling some holes to tie a couple of rope handles on and just plonking it on.
I suppose an alternative would be to get a bit of steel angle or square tube and bolt it into the concrete across the steel plate. Might stop it slowly walking off the shaft with cows standing on it. Hmmm.
Neither hole will see many visits so effort for lid construction is really not a priority.
pwhole
Well-known member
I suspect that if the lid isn't fastened down, the cows will find a way to move it - they just can't help poking about. That shaft near Elton that swallowed a cow a few years back had a cover on, though it may have just been timber or wriggly tin - but it was all long gone (and the cow long dead) by the time we got there.
It would seem to make sense to put any bolts well away from the edges - maybe a couple of clamping bars are better? So the lid is unfastened, but registers in the hole so it won't slip sideways. If one end of each bar was hinged there would only be one bolt on each to fasten? If they were done with expansion sleeves the bolts could then be screwed downwards into the sleeve rather than them protruding upwards. Granted the holes would have to be kept very clean and cavers mustn't lose the bolts!
It would seem to make sense to put any bolts well away from the edges - maybe a couple of clamping bars are better? So the lid is unfastened, but registers in the hole so it won't slip sideways. If one end of each bar was hinged there would only be one bolt on each to fasten? If they were done with expansion sleeves the bolts could then be screwed downwards into the sleeve rather than them protruding upwards. Granted the holes would have to be kept very clean and cavers mustn't lose the bolts!
Pete K
Well-known member
I can get 3m of 6mm thick, 80mm wide flat bar for ?30 + postage.
https://www.themetalstore.co.uk/products/3-metre-lengths-6mm-flat-bar
Cut that in 2 and drill holes at either end to bolt down to concrete across the lids. That would clamp the sheet in place and stop cows disturbing it. I think I'll go down that route.
Anyone got anything similar kicking about before I order some?
Now I need to figure out handles. It's too heavy to lift without any. If I cut slots I recon someone is going to break their fingers on them. I could use some steel wire rope swaged through holes to create lifting/drag handles I suppose, or rope loops. Bolt through handles seem to be ?20 a piece and not cost effective.
https://www.themetalstore.co.uk/products/3-metre-lengths-6mm-flat-bar
Cut that in 2 and drill holes at either end to bolt down to concrete across the lids. That would clamp the sheet in place and stop cows disturbing it. I think I'll go down that route.
Anyone got anything similar kicking about before I order some?
Now I need to figure out handles. It's too heavy to lift without any. If I cut slots I recon someone is going to break their fingers on them. I could use some steel wire rope swaged through holes to create lifting/drag handles I suppose, or rope loops. Bolt through handles seem to be ?20 a piece and not cost effective.
Pete K
Well-known member
Ah, I have found a length of galv angle (70mmx50mmx5mm) in the garden left over from Vixen shaft. I could cut that into 10cm chunks and bolt down to concrete on 2 sides of the lid to engage with a little cut-out to prevent movement in any direction. Bonus of that is that I have it here and it won't cost any more money to do. Does not solve handle problem though.
pwhole
Well-known member
We're not wasting a gas strut on this 
If one side of the lid was hinged on captive bolts though, that would take a lot of the load, especially from beneath? The hinge would have to be pretty close to the hole though or the angle would remove the advantage. The issue then though, as we found elsewhere , is that you need something solid to stand on to push the damn thing up. Although I guess we do have 'solid' ginging in this one. Not worth pointing it all up though - there's far more important jobs to do. Is there a plan to put anchors in these shafts?
If one side of the lid was hinged on captive bolts though, that would take a lot of the load, especially from beneath? The hinge would have to be pretty close to the hole though or the angle would remove the advantage. The issue then though, as we found elsewhere , is that you need something solid to stand on to push the damn thing up. Although I guess we do have 'solid' ginging in this one. Not worth pointing it all up though - there's far more important jobs to do. Is there a plan to put anchors in these shafts?
Brains
Well-known member
Fix the lid in place with a scaff tube bolted down tight to "U" bolts either side in the concrete... Bolts with a bracket etc to act as a belay bar when open? Thinking like the big shaft at Snake Mine if you know that?
Attached (?) a picture by Renuka Russel showing the open lid with in situ gurning troglodyte. When closed the scaff tube holds the lid down firmly...
Attached (?) a picture by Renuka Russel showing the open lid with in situ gurning troglodyte. When closed the scaff tube holds the lid down firmly...
Attachments
Pete K
Well-known member
I might have another shaft for that! I've got 2 lids with bat holes and handles cobbled together now. They are both lift on and off jobs but these sites are not going to get a lot of traffic, so simple is fine. I am now turning my attention to a plan for the Slitherstones shafts themselves. Time to get rid of those concrete sleepers.
Tseralo
Active member
I think if you can find a way to have a captive scaff bar as we did at longcliff I think that would be way better than the sliding ones. They either a too loose and risk being knocked down the shaft (see oxlow) or too tight especially if they get mud in them (see eyam dale house cave)
