Author Topic: Climber's "how to" bolt  (Read 633 times)

Offline mikem

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Climber's "how to" bolt
« on: November 09, 2020, 12:07:30 am »
https://www.andy-kirkpatrick.com/blog/view/hand-bolting

He's also just written a whole book on abseiling.

UK Caving

Climber's "how to" bolt
« on: November 09, 2020, 12:07:30 am »
Warmbac

Offline mikem

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Re: Climber's "how to" bolt
« Reply #1 on: November 09, 2020, 09:41:23 pm »

Offline Stuart France

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Re: Climber's "how to" bolt
« Reply #2 on: November 09, 2020, 11:10:28 pm »
The BMC's document is from the noughties.  A lot has learned by everyone since then and I don't think any cavers would be using spits to place new bolts nowadays though it was normal practice 20 years ago and documented as such.

I'm looking at the French version of "Alpine Caving Techniques" by Marbach et al, I have the 2000 edition in French, and I think the English version appeared in 2002.  First up are spits, then sleeve bolts, then resin bolts, and finally pitons!  Seriously.

Climbers have had trouble with bolts (screws really) intended for building sites fitted with impact drivers, and there have been problems with A4 bolts and chloride stress corrosion fracturing on sea cliffs with bolted routes done in A2/A4 material (and swimming pool roofs falling down too) so you live and learn.

https://www.thebmc.co.uk/bolt-corrosion-warning-from-the-uiaa

BCA has settled on resin bolts, with mixed results and conversations it has to be said, but 10mm OD by 85mm long A4 stainless sleeve bolts with no-nonsense A4 anchor plates take some beating.  That's what we used for the Daren chain ladders put on the Busmans route.

Aluminium anchor plates held in passivated old-school spits with ordinary steel machine screws (and so forth) with a chloride or acidic environment is utterly bonkers.  People should know that without having to see pictures of the results in books.

The same applies to galv maillons.  You should see the 20 years old ones recovered from Daren in a nice little display box in the Whitewalls library that once held the 60ft ladders.  Once the galv layer wears away they are not long for this world in a damp enviroment.

What's needed is excellence.  The best materials coupled to engineering overkill.


« Last Edit: November 09, 2020, 11:40:47 pm by Stuart France »

Offline mikem

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Re: Climber's "how to" bolt
« Reply #3 on: November 10, 2020, 12:54:08 am »
Yep, I was only putting it up for comparison, hence the inverted commas.

 

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