ARF

ARF - Anchor Replacement Fund

The recent bolt failures in the Western Cape have resulted in many of us questioning the integrity of the anchors that ensure our safety. Its quite obvious that some of our seaside crags have rusty old bolts that need to be replaced. So in order to get the ball rolling ARF has been launched. Is it a UFO? No it’s the Anchor Replacement Fund. It has been limited to the Cape for now in order to keep the project manageable.

Phase 1 of the project will aim to rebolt the following crags:
• “The Mine”
• “The Hole”
• The Silvermine Crags

This will be achieved by:
• Raising approximately R35,000
• Purchasing 800 glue in eye bolts and 200 lower off rings.
• Training approximately 10 volunteers to install the bolts
• Installation at the above crags

The MCSA will manage the finances and has accordingly created a separate ARF fund. The strategy for fundraising is currently as follows:

• Corporate sponsors will be asked to donate cash in exchange for some free advertising on various websites and notice boards. Corporate sponsors will be ranked according to the amount of money they donate. Please support these guys.

• Individual climbers will be asked to donate R200 to support this project. R200? Lets see that's 4 visits to a climbing gym or 4 pizzas – not a bad investment considering its your life. Of course if you are rolling in cash please feel free to donate a lot more.

Here is some background info

The first bolt failed in Montagu at the Alley. This is a dry low chloride environment (this is evident by the state of the mild steel bolts in this area). No one was hurt during this failure as it was one of two lower off anchors. The second bolt failed at Silvermine Crag in Cape Town which is a relatively high corrosion area, but there are worse areas, like The Hole, The Mine and Peers Cave. Nobody was hurt in this failure as they were top-roping and hung on the bolt. It’s pretty scary that both these bolts failed only with body weight!

The failed bolts were sent to a materials analysis company who concluded the following:
• Both bolts were Stainless Steel 304
• Both bolts were machined on a lathe (turned vs rolled)
• Both bolts failed due to Stress Corrosion Cracking (SCC)

For SCC to occur it requires 3 conditions:
1. Susceptible material (Stainless steel 304 is susceptible)
2. Tensile (pulling) force, this is due to the permanent tension on the bolt as a result of a climber’s overtorqueing bolts to prevent hanger spin. Climbers falling or hanging on a bolt will have negligible effect on SCC as it is for such a short time.
3. Chloride environment - The salt laden NW and SE winds in Cape Town paste Chlorides over the bolts and the chloride concentration will build up unless the bolt is washed by pure rain water. Therefore bolts in overhangs that do not get washed by rain water are in fact more susceptible to SCC.

Two other factors will exacerbate SCC:
1. Higher temperatures will accelerate SCC but this isn't really applicable here
2. Machining a bolt on a lathe (turning) will create tiny circumferential scratches on the surface which act as stress concentrations in a the most penalising plane and they also act as microscopic areas where Chlorides collect.

In order to remove these phenomena from our bolts we can do the following:
Use bolts that have been rolled instead of turned. The two reputable bolt suppliers (Hilti and Fischer) only supply rolled bolts now.

Use better materials. Stainless Steel 316 is far better than Stainless Steel 304 and is used in marine applications. Some materials engineers would prefer other more exotic materials, but these can cost as much as R60.00 per bolt.

Reduce the tensile forces. This can be done by using glue-ins. For the currently used express anchors one can use a spring washer to ensure minimum tensile stress whilst preventing hanger spin.

Therefore the following bolts are recommended for use:
Hilti / Fischer 10mm Stainless Steel 316 express anchor

From Fischer the stock ref is:
146-1007 FBN 10 x 89 A4 (316)

Trained Volunteers:
Stainless Steel 10mm glue in eye-bolt (Although this is the best option, the risk of installation error by untrained climbers is greater than the risk of SCC)
Training on how to place anchors will be provided.

Disclaimer * this feedback has been compiled by concerned climbers and not as a professional engineer / person or company.

A Raumer bolt that will be used to replace the old bolts/anchors

One of the bolts that failed

Interesting links:

Snap Hooks & Quick Links - How many Kn does it take to break?
Bolting info from SACIN
Re-bolting in Thailand (with titanium bolts)

How to donate?

You can make cash or cheque deposits at the MCSA or make an electronic transfer to:

Bank: Standard Bank
Branch: Cape Town
Branch Code: 020009
Account No: 071556060

Send us an email to info@climbing.co.za and also please state on your deposit details: “ARF Initials Surname” (eg ARF I.R.Scared) so we can identify it as a ARF deposit, give you a tag and put your name up in lights!

We are also looking for technically minded volunteers with some bolting experience to place the bolts. Please contact Ross McBride at skysite@mweb.co.za if you are keen.

ARF Meet reports:

Peers Cave ARF meet (June 2008)

ARF at Fawlty Towers - poor turnout (April 2008)

Lions Head sandstone abseil anchors (December 2007)

ARF at Peers Cave (March 2007)
ARF at Peers Cave (January 2007)

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