North Wales Limestone Bolt Wear - A Solutionby Chris Parkin Jul/2007
This news story has been read 2,470 times
See a photo of the problem : here
Many of the DMM Eco bolts used as lower-offs at the top of routes on Lower and Upper Pen Trwyn, Llandudno, North Wales are starting to show signs of wear due to the practice of lowering off and top roping with ropes threaded directly through the bolt eye. See bad practice and a solution : here
Some of this wear is serious and well beyond the DMM recommended limit.
Most of the bolts are still soundly fixed in the rock but if the wear is to continue replacement will be required. An awkward, difficult and expensive task that costs at least £14 per double lower-off plus all the effort and associated risks to the volunteers who will have the task to drill and install.
To address the problem the BMC and The NWBF (North Wales Bolt Fund) have recently purchased 300 marine grade stainless steel maillons and 300 marine grade stainless steel certified welded rings - this is sufficient for 150 lower-offs and should be sufficient to sort most of the popular routes on upper and Lower Pen Trwyn.
The rings are certified to 4,750 kg so even big George Smith and big John Dunne can be sure they will take the strain
Installation has started with a maillon and ring on each of the two lower-off bolts - this is been done by trained volunteers who are also testing the bolts at the same time.
Severely worn bolts all be replaced.
Now you know what is been done and why please use the rings to thread your rope. Do not thread the maillons. Do not thread the bolt eyes.
For the scrap-men and magpies out there, please leave the shiny new kit in place it cost £9.05 per lower-off station!
If you use a lower-off without rings then lower off your own draws except the last person. If you plan to top rope then get some screw-gates on until your done.
Big thanks to all involved.
The NWBF is currently in debt by over £500 and is in need of financial assistance, please send donations to:
Any one interested in helping out with the re-bolting of routes on the Ormes should check out thenorthwaleslimestone.wetpaint.com
In related news, Dan Middleton (BMC Technical Officer) reports that on 18th July The North Wales Bolt Fund held a bolting workshop at Bus Stop Quarry, Llanberis. Despite the best sunny weather for over a week, more than 20 local climbers attended. Participants learnt how to use the petrol and battery drills, and how to place expansion bolts. Pull out tests of the expansion bolts used on the slate gave good results considering the nature of the rock. All except one (which managed to find a dubious bit of rock) held at least 9 kN.
Some of the issues affecting resin bolts were covered, and some of the resin systems were looked at. Some very encouraging pullout tests were made on some DMM Eco-bolts and Fixe eyebolts. Using a range of different epoxy acrylate resin systems, all held in excess of 15kN.
Full report at thebmc.co.uk