Mine exploration, photographs and mining history for mine explorers, industrial archaeologists, researchers and historians Mine explorer and mining history videos on YouTube Connect with other mine explorers on Facebook
Tip: do not include 'mine' or 'quarry', search by name e.g. 'cwmorthin', use 'Sounds like search' if unsure of spelling

Advanced Search
'Sounds like search'
Quick a b c d e f g h i j k l m n o p q r s t u v w x y z
Tip: narrow down your search by typing more than one word and selecting 'Search for all words' or 'Exact search'

Search for any word
Search for all words
Exact search
Tip: narrow down your search by typing more than one word and selecting 'Search for all words' or 'Exact search'

Search for any word
Search for all words
Exact search

Mine Exploration Forum

Jump to page << < 1 2 3 > >>
Author Bolts and bolting
davel

Avatar of davel

Joined: 24/07/2007
Location: Gwynedd

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 03/12/2011 15:46:00
Reply |  Quote
Most of the in-situ bolts I've come across in recent years are 10 mm. However, in topic http://www.aditnow.co.uk/community/viewtopic.aspx?t=6292&pid=1 Simon wrote:

simonrl wrote:

My bolts are all 12mm

Having spent some of the afternoon finishing off some home-made hangers with 12 mm holes to fit Simon's bolts, it's occurred to me to wonder what size bolts people usually install.

Whist I'm dubious about 6 mm bolts (or rather 6 mm bolts in Petzl Spits - see my posting in topic http://www.aditnow.co.uk/community/viewtopic.aspx?t=6158topic about this) I'm generally quite happy hanging off 10 mm expansion bolts (providing of course that there's at least two of them and they are well spaced).

On the subject of bolting - how many people carry a hammer to tap the rock to see if it sounds sound before drilling?

Dave

IP: 195.137.87.110
stuey

Avatar of stuey

Joined: 15/08/2007

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 03/12/2011 16:07:42
Reply |  Quote
Always carry a load of 10mm plates and bolts. Down here it's all 10mm in situ, or holes for M10 rawlbolts (16mm holes)

Mineral hammer is a good whacker.

Your mention of home made hangers is going to get the hysterics going.

"Would you use a home made rope?"
IP: 46.208.75.57 Edited: 03/12/2011 16:10:08 by stuey
sinker

Avatar of sinker

Joined: 13/12/2010
Location: North Wales.

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 03/12/2011 16:37:58
Reply |  Quote
stuey wrote:



Your mention of home made hangers is going to get the hysterics going.


Laugh Nothing wrong with home made hangers or anything else, as long as it's they're made properly. I trust my own "quality control" more than I would a lot of manufacturers' Wink

--

O'r graig, egni.
IP: 86.169.159.88
droid

Joined: 31/10/2010
Location: Tamworth

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 03/12/2011 17:30:31
Reply |  Quote
Dave, i think you're being unneccessarily disparaging regarding 6mm spits. I've done dozens on pitches on these. Never had a problem. Thing to remember is that they were always meant as a rather temporary solution to the problem of belaying a pitch.

Also, if you're Old Skool you put 'em in with a hammer.
That tests the rock pretty adequately.... Laugh
IP: 81.108.217.215
davel

Avatar of davel

Joined: 24/07/2007
Location: Gwynedd

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 03/12/2011 17:49:34
Reply |  Quote
stuey wrote:

... home made hangers ... "Would you use a home made rope?"

They are from 6 mm stainless angle and a bit on the heavy side but I'm happy with them. Obviously, that's a personal choice and I wouldn't expect anyone else to use them if they didn't like the look of them.



droid wrote:

... 6mm spits. I've done dozens on pitches on these. Never had a problem. Thing to remember is that they were always meant as a rather temporary solution ...

I've done many pitches on them as well and likewise never had a problem - until one failed on me on a deviation recently. The other problem is that their temporary nature led to a rash of them at the head of many pitches in Yorkshire pots - which is why people started installing a more permanent solution in the form of resin-fixed P-hangers.

Dave
IP: 195.137.87.110 Edited: 03/12/2011 17:51:24 by davel
stuey

Avatar of stuey

Joined: 15/08/2007

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 03/12/2011 18:29:54
Reply |  Quote
I was looking at having a load of hangers made by my metal-cutting-and-folding mate as principle prevents me paying over the odds for what is effectively a deluxe washer.

...and then a mate with loads of kit who was retiring sold me his collection of pukka ones for cheap. Jolly good!

However, I would have no trouble with using bits of metal with holes in them which were made in a shed if my 10mm ones didn't fit.

I was reading the old SRT book by that Aussie Bloke from back in the day and the anchor methods which were originally also used would make a lot of modern rescue-conscious folks wet their beds in horror. Chock stones, buried stemples, etc. :D
IP: 46.208.75.57
sinker

Avatar of sinker

Joined: 13/12/2010
Location: North Wales.

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 03/12/2011 19:03:11
Reply |  Quote
stuey wrote:

I was looking at having a load of hangers made by my metal-cutting-and-folding mate.....


Just an observation, but I would prefer to start with pre-formed angle bar, cut to the required shape, rather than starting with flat bar and puting the bend in myself. Thumb Up

--

O'r graig, egni.
IP: 86.169.159.88
davel

Avatar of davel

Joined: 24/07/2007
Location: Gwynedd

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 03/12/2011 19:37:50
Reply |  Quote
sinker wrote:

... I would prefer to start with pre-formed angle bar, cut to the required shape, rather than starting with flat bar and puting the bend in myself.

Likewise. If I was using sheet I would want to be very sure what grade of steel or alloy I was using, have some sort of press tooling to get consistent bends without nicks and have facilities for heat-treating it to remove residual stress after bending. (I think this is a "don't try this at home" - I certainly don't have facilities for that sort of work at Gweithdy Davel.)

That said, the 6 mm angle I've used is almost certainly overkill for the application.

In my opinion the thing to avoid with home-made hangers is using short pieces of angle with the holes opposite one another. When loaded, such hangers tend to put all the stress on the bend and also convert the downwards load to an axial pull on the anchor as the angle acts as the fulcrum of a bell-crank. (Even worse of course is when such hangers are made from a rusty bit of bed-angle! Thumb Down )

[As an aside, if anyone wants to see how it's done professionally I would recommend going on one of the DMM open-day tours at their factory at Llanberis.]

Dave
IP: 195.137.87.110
pat

Joined: 22/11/2007

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 03/12/2011 19:49:57
Reply |  Quote
I am a big fan of wire hangers myself,small loops of wire which can synch around the shaft of a stud even if the thread is knackered . Can be a bit marginal but will do if someone has been nicking hangers and will fit around all but the biggest studs so need for different size hangers , nuts and spanner.of course a bit of common sense may be required. IP: 213.130.122.195
KH....

Joined: 27/10/2010

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 03/12/2011 23:09:05
Reply |  Quote
Don't get me started about people Stealing hangers! Many have been stolen in Cornwall, they where left in place for a very good reason, paid for out our own pockets.
Possibly for your benefit one day.

Rant over, could you put them back please! If not for your sake but they could help others when they need it most.
Edited.
IP: 95.147.59.90 Edited: 05/12/2011 18:12:39 by KH....
Roy Morton

Avatar of Roy Morton

Joined: 09/10/2007
Location: Redruth Cornwall

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 04/12/2011 01:42:37
Reply |  Quote
Many years ago, I came to the foot of an inclined pitch which someone had shot fired blocks of 3x2 to get up the raise.
It was certainly a novel approach to climbing. we gave one a good whack with a 1kg lump hammer and it took a dozen almighty whacks just to loosen it.
I prefer bolts and good hangers whether they be shop bought or home brew. If you've any sense of engineering in you, then it's easy to spot a goodun from a badun.
The stainless angle ones are excellent and generally over-engineered to hell Thumbs Up

--

'Bid me discourse, I will enchant thine ear'
IP: 86.150.102.234
pwhole

Avatar of pwhole

Joined: 22/02/2011
Location: Sheffield and the Peak District

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 04/12/2011 19:40:53
Reply |  Quote
We generally use cheaper short-sleeve 8mm anchor bolts for climbing pitches for the first time, and then two 8mm Rawlbolts or similar for any subsequent Y-hang up to about 10 metres. Higher than that and the 10mms come out, but they've not been necessary on the small stuff. Many of the pithes we've recently rigged have been quite tight and also often hading, so there's less chance of a straight drop as you're pretty much jammed in a body-sized gap with plenty of friction. IP: 81.174.241.13
Mr Mike

Avatar of Mr Mike

Joined: 09/06/2007
Location: Bury - In The Laboratory

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 05/12/2011 08:15:21
Reply |  Quote
Always tend to use M10 100mm SS through bolts, and M8 for deviations.

--

Mr Mike www.mineexplorer.org.uk
IP: 79.70.74.3
royfellows

Avatar of royfellows

Joined: 13/06/2007
Location: Great Wyrley near Walsall

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 05/12/2011 10:53:04
Reply |  Quote
Caving Supplies have 10mm stainless off the shelf for £2.50, so to me its not worth messing.
I use these with 10mm through bolts put in with a 24V DeWalt (latest DC223)which came off eBay for £93 with charger and spare battery.
Methinks a bargain.

--

''Clearing this would take a major engineering job ''-Prof David James, Henfwlch Mine, 2011
IP: 78.151.47.252 Edited: 05/12/2011 10:53:34 by royfellows
davel

Avatar of davel

Joined: 24/07/2007
Location: Gwynedd

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 05/12/2011 19:16:35
Reply |  Quote
royfellows wrote:

Caving Supplies have 10mm stainless off the shelf for £2.50, so to me its not worth messing.

I would totally agree with Roy on this. The CS ones are significantly lighter and smaller and as well as the cost of the angle there's the cost of the cutting disks to think about as well.

The only reason I made some myself was that I had some stainless angle 'in stock' and wanted the hangers sooner than I could have got them from CS. (As it happened they weren't needed after all! Sad )

Dave
IP: 195.137.87.110
Alasdair Neill

Joined: 10/12/2008

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 06/12/2011 09:39:40
Reply |  Quote
The use of 10mm bolts is slightly concerning - 8mm has been the standard in caving for many years, what everyone uses, & it's really annoying to find "non standard" anchors. Some sites in west Cornwall have suffered fronm an excess of "bolt rash" with all sorts of people putting there own bolts in when there are already perfectly adequate anchors there already. Some of these have been placed in totally ridiculous places, indicating the installer has no real knowledger of SRT, eg a traverse where hangers have been left but no rope.
Re leaving hangers in situ, it has always been normal practice to remove the hangers unless there is a really good reason otherwise, normally only because ropes are being left in situ as well. Any piece of equipment left underground will deteriorate, particularly in West Cornwall with often either acidic conditions or the effects of salt spray. If you are not aware of the history of a bolt you wish to use you need to inspect the rock round the bolt head carfeully, you can't do that if there is already a hanger there.
I would suggest anyone wanting to carry out rebolting in Devon & Cornwall should at least liase with the regional council (DCUC); hopefully there will be progress soon in making p-hangers available.

IP: 46.60.252.97
royfellows

Avatar of royfellows

Joined: 13/06/2007
Location: Great Wyrley near Walsall

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 06/12/2011 10:42:12
Reply |  Quote
Indeed 8mm have been the standard, and also the subject of many recorded failures.
I struggle very badly to appreciate any attraction in an age where high efficiency self contained drills such as the DeWalt or whatever are now freely available. I have just checked the length of my 10mm through bolts at about 3.5 inches or 85mm. With this depth of penetration, assuming that the rock was suitable for bolting in the first place, I cannot see anything like the same risk being presented as by the use of the old 8mm spits.

I agree comments about hangers left in situ, but see this as only being relevant to the 8mm spit, here there is a 'no win' situation. If the hanger is removed the threads can corrode, fortunately the more recent ones are stainless. If the hanger is left in situ, as Ally says there is no way of knowing the condition of the bolt or surrounding rock, which is probably the reason for all the rebolting.
The logical answer to this must be a properly placed stainless 10mm through bolt where anything has to be left in situ.

My practice generally is the use of the through bolts but removing the hangers after use while leaving the nut for re use. At £2.50 a hanger, there is good enough reason for removing them anyway.

I am aware of the 10mm self drilling variety but cannot see the point in them.

--

''Clearing this would take a major engineering job ''-Prof David James, Henfwlch Mine, 2011
IP: 78.151.47.252
Alasdair Neill

Joined: 10/12/2008

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 06/12/2011 11:00:05
Reply |  Quote
Of course this subject has been the cause of endless debate in the caving world. There have been problems with 8mm bolts, BUT with proper rigging these are perfectly safe. As soon as people use 10mm without leaving the anchors it causes big problems for most other people going there who will probably only use 8mm. Of course many people argue they are only putting the bolts in for their own use, but I think that is really just selfish, you should always consider that other people may want to follow you on your explorations. I stronly recommend the only options to be followed should be: 8mm spits or studs (stainless ideally) with hangers removed when not in use
or P hangers installed under the BCA scheme
or rawlbots if the latter are not yet available where rock/enviroment precludes the use of anything else.
I really think the above is the norm for cave/mine exploration in the UK & elsewhere in Europe for many years, & going away from the norm just adds unnecesary complications. As everything included above (perhaps bar the use of rawlbolts which is only really a last resort) has had exrensive scrutiny from the BCA equipment committee etc & similar bodies abroad, I really can see no point in trying to reinvent the wheel.
IP: 46.60.252.97
stuey

Avatar of stuey

Joined: 15/08/2007

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 06/12/2011 11:54:59
Reply |  Quote
I see a fair amount of resined in hangers, alongside M10 and M12 whack ins, some spit sockets and the usual Rawlbolt holes (16mm).

I'd say that down here, 16mm holes and spits are the things I cross the most. Whack ins left in situ are becoming more common as there are a bunch of people running around with them, who weren't beforehand.
IP: 92.29.174.12
royfellows

Avatar of royfellows

Joined: 13/06/2007
Location: Great Wyrley near Walsall

View Profile
View Posts
View Personal Album
View Personal Files
View all Photos
Send Private Message
Bolts and bolting
Posted: 06/12/2011 12:58:51
Reply |  Quote
First and formost I am not a caver but a mine explorer, and as such I travel around quite a lot, my specialist area being mid Wales.

I am doubtful that my bolting techniques will cause a problem simply because I dont do any outside of my own turf where mine are the only bolts being placed. I regularly get asked for info re 'my' mines and always advise about rigging requirements.

From what I see elsewhere permanent brackets made from angle and fixed using 10mm throughbolts or rawlbolts are very common up north, Nenthead and the Lakes.
Although I still visit the West Country two or three times a year, nowdays I do very little there underground.

I rather fancy any disagreement will remain accademic.
Big Grin

--

''Clearing this would take a major engineering job ''-Prof David James, Henfwlch Mine, 2011
IP: 78.151.47.252
Jump to page << < 1 2 3 > >>
Moore Books: Specialist Books I.A. Recordings: Mining and Industrial History DVDs Starless River - Caving Store Explore a Disused Welsh Slate Mine
Disclaimer: Mine exploring can be quite dangerous, but then again it can be alright, it all depends on the weather. Please read the proper disclaimer.
© 2005 to 2015 AditNow.co.uk
Top of Page