Materials for dig support

Speleokitty1

New member
Hi Guys

We are about to restart shaft sinking at Bonsall Moor Swallet upper sink and I'm trying to decide on the best king of support for behind our scaffolding cage.  We were hoping to get a machine on site and put a pipe in before backfilling but the land owner isn't up for that so it looks like we are back doing things the hard w.ay I'd really like some feedback from other peoples experience.  My initial thoughts are:
.
Scaffolding boards - Easy to use and strong but they don't seem to last very long especially near the surface. On the plus size they can often be got very cheaply if you know a site that is being cleared.

Tanalised Board - Easy to use and lasts longer than scaffolding boards but can be of variable quality. Good quality board seems expensive.

Half round fence posts - Easy to use and seem stronger than sawn board. The pointy end is easy to drive down. Can be expensive for good quality posts.

Corrugated Steel - Stuff from the 40's and 50's seemed good but almost impossible to get hold of now. New stuff seems so thin that it won't hold any weight.

Used Domestic radiators - I have no experience of these but they seem quite strong and will probably last longer than timber. Probably more difficult to use than other options but a 9" grinder will sort most things. Steel scrap prices are currently low.

Any thoughts very welcome.

Thanks

Julie

 

manrabbit

Member
Crash barriers are idea if you can get hold of them, they are galvanized so will last pretty well underground. Worth trying some of the road building companies such as Costain as they like to be seen to have a social responsibility and do donate to local projects. They're building a 3G football pitch at Brynmawr school to compensate for the disruption caused by dueling of the Heads of the Valleys road.
 

tamarmole

Active member
Speleokitty1 said:
Hi Guys

We are about to restart shaft sinking at Bonsall Moor Swallet upper sink and I'm trying to decide on the best king of support for behind our scaffolding cage.  We were hoping to get a machine on site and put a pipe in before backfilling but the land owner isn't up for that so it looks like we are back doing things the hard w.ay I'd really like some feedback from other peoples experience.  My initial thoughts are:
.
Scaffolding boards - Easy to use and strong but they don't seem to last very long especially near the surface. On the plus size they can often be got very cheaply if you know a site that is being cleared.

Tanalised Board - Easy to use and lasts longer than scaffolding boards but can be of variable quality. Good quality board seems expensive.

Half round fence posts - Easy to use and seem stronger than sawn board. The pointy end is easy to drive down. Can be expensive for good quality posts.

Corrugated Steel - Stuff from the 40's and 50's seemed good but almost impossible to get hold of now. New stuff seems so thin that it won't hold any weight.

Used Domestic radiators - I have no experience of these but they seem quite strong and will probably last longer than timber. Probably more difficult to use than other options but a 9" grinder will sort most things. Steel scrap prices are currently low.

Any thoughts very welcome.

Thanks

Julie

Can you get hold of any Armco (the stuff they make motorway crash barriers out of)? 

Failing that if you can get some decent scaff planks give them a good dowsing in creosote (the modern substitute stuff isn't too bad these days).
 

The Old Ruminator

Well-known member
Sometimes its about aesthetics. Our shaft is 7m of concrete pipe and we have used some scaffolding. We dig with two teams. One likes the scaffolding approach and one likes to build cemented walling. If you have been into Reservoir Hole you will see that Willie Stanton was a purist and nearly everything is dry stone walling with no artificial aids. Willie et al were craftsmen in that respect. We have learned from Reservoir that you will inherit a long term responsibility for your actions. If your dig becomes a trade route folk will look to you to keep it safe for years. Therefore its better to have a plan that will last the test of time.

Scaffolding set on 10mm pins in the wall then cemented over.



Cemented wall with electricity supply to drill.



Large diameter concrete shaft now fitted with fixed ladders.



Cemented keystone and scaffolding in Reservoir Hole.



Below the Acro prop. Rotproof farm ballast bags ( sausages ) which when muddy dont look too bad.



Dry stone walling in Topless Aven Dig Reservoir.



Planked walling in The Silo, Reservoir. Might last ten years but then what ?



Cemented wall building  in Reservoir. Long term the best.



Dry stone walling in Reservoir. To my mind the best way as its permanent and looks the best. You do need a good supply of regularly shaped boulders. You can use plug and feathers to some shaping. Also you can infill behind the wall.



Every site has its own problems and answers. Think long term re materials ( ten years plus ) and try to keep things sympathetic to the environment in the cave. To my mind motorway galvanised fencing would look horrible.
 

The Old Ruminator

Well-known member
Stanton dug UPWARDS for maybe a total of 100ft without any artificial aids at all. Its all dry stone walling.

Part of the long climb up to Golgotha all dry stone walls.


 

Badlad

Administrator
Staff member
I'd suggest 6x1 tanalised which costs is about 90p per metre and should last about 30 years.  It is best used if you drive the boards down as you dig with scaffold rings about every 800mm.
 

alastairgott

Well-known member
Interesting spot for a dig.

Do you know why the landowner is uncomfortable? Is the landowner comfortable with you digging the hole?

Could be just a case of talking through their concerns and putting them at ease.

Anyway there are many more options if you can get gear onto site.

We have manhandled sections of approx 1.5 or 2m Diameter pipe into a hole and are backfilling with an alternating mix of concrete and rocks. the pipe we used is similar to this http://www.alibaba.com/product-detail/2014-best-selling-hdpe-culvert-pipe_60128270333.html?spm=a2700.7724838.30.57.sxsJm1

could find out exactly what we ordered if you need.

I have seen other digs which have used road furniture like this http://www.parker-direct.com/product/1030045295/Technotrak-Safetycross-Walkway-Board-1080-X-1080mm supplier or method of obtaining up to you.
but they were used to hold back spoil from above rather than to the side.

concrete is also an option, we're using a concrete mixing board http://www.toolstation.com/shop/p43112?utm_source=googleshopping&utm_medium=feed&utm_campaign=googleshoppingfeed&mkwid=sXMBw15Gg_dc&pcrid=68756281583&pkw=&pmt=&gclid=Cj0KEQjwqZKxBRDBkNmLt9DejNgBEiQA it is slow and very hard work, but the best option if generators and concrete mixers are not an option.

Depending on what you're trying to achieve you might also be able to use conveyor belting? If you could place it horizontally round the outside of the scaffolding, it might do a reasonable(?) job of holding back some spoil, though I have doubts... lots of options http://www.ebay.co.uk/bhp/conveyor-belt

notts 2 entrance is made of concrete breeze blocks.
 

alastairgott

Well-known member
I would presume you're short of space, but in case you aren't then gabion baskets could be an option, or at least the metal cages (if the dig is relatively clean) http://www.devoran-metals.co.uk/gabions-steel.html

I guess if you don't want the gabions in the fully formed square shape, then you could disasemble and get 5 or 6 square sections for 25-50 quid. http://www.devoran-garden-gabions.co.uk/products.php

This would allow you to use conveyor belting behind if you needed to hold back spoil. (Although these are only thoughts... I don't think anyones actually tried it)
 

Brains

Well-known member
Some of the repairs in Oxlow at the bottom of pitch 1, where a new pitch is growing, have been done with armco that was obtained from the M6 (legally, after repairs were made). There maybe some more left over somewhere, or perhaps the orignal source has some more...
 
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