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Bolting has grown up in a rather informal environment. Often climbers wish to bolt or open a route and then proceed to ask their friends how. Knowledge on bolting is dependant on users preferences, budgets and individual skills and savvy. As a result many bolted routes today have bad bolts, some homemade, many very rusted and often badly positioned too.
Alan Jarvis and Joffrey Hyman set about to do some proper testing of different bolt types in different rock types. Many of the previously used bolts were also tested to try and acertain how safe they really are.
Test Results for Soft Sandstone
The first test results are out. We set out to test bolts, especially U-bolts (staples) in soft sandstone as is found in the Freestate and areas in Kwazulu/Natal. There is a concern about the integrity of the anchors due to the soft/friable nature of the rock. Alan Jarvis & Joffrey Hyman did the testing at Swinburne, south of Harrismith. The rock here is very similar to Mount Everest Crag, Harrismith. To date, routes at Swinburne have been bolted using mainly glued-in Ubolts from various sources. Mnt Everest has both expansion bolts and a few types of U-bolts.
A hydraulic testing machine from UPat was used which was calibrated before the testing. It is equipped with a hydraulic piston and pressure gauge. A testing rig was also manufactured in order to test the bolts in tension, as well as in shear.
The testing was done over two days with most of the drilling and glueing done on the first day. Both the Epidermix 372 and Hilti HY-150 glue which were used were given 24 hours to cure. 44 bolts were placed of the following types:
(1) Davies 7mm U-bolt
(2) Long 8mm U-bolt
(3) Wide 8mm U-bolt
(4) Short 10mm U-bolt
(5) Medium 12mm U-bolt
(6) Short 12mm U-bolt
(7) Hilti mechanical expansion bolt
(8) M10 glue-in stud (two different glues)
(9) M8 glue-in stud
At least three tests on each variety of bolt in both tension and shear mode were attemped but due to time, battery, and glue restraints a few instances were not tested. The results do however allow analysis of both the existing bolts and potential others.
Full Report – including Images of Test Rig & Bolts used/ pulled
Summary of Testing
Test Results
Recommendations
Test Results for Hard Sandstone
To be added.
Bad Bolts
Examples of some bad bolts found at Fernkloof in Magaliesberg. Most of these have already been replaced.
Web Resources
ASCA, American Safe Climbing Association, excellent recomendations on bolting, replacements etc.
Fish Products, Information and supply of bolts etc.
Fixe, Hangers, & other anchors
Hilti, manufacturer of drills, glues and bolts.
Metolius Hangers, hangers including a special rap-hanger.
Petzl, supplier of bolts including eye-bolts.
Pika Mountaineering, Suppliers of a wide range of bolts and drilling equipment.
UPat, manufacturer of bolts and glues.