Nuts & Bolts 1: Bad Bolts and What to Do

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Read Time - 10+ Minutes

July 2020

You’re boxed out your mind, lungs heaving, it’s cold but you’re sweaty, is that fear sweat or exertion? Hard to tell, probably both.

You look up and see something glinting on a lofty slab, a few more delicate steps and stiff pull guard it. Clipping it provides a moment of relief and the chance to reconsider your life choices. Done that; still like sleeping in your car in some dark car park behind a ski lift? Check; time to carry on climbing, tomorrow might be a rest day though.

Whether sport climbing, big walling, or in the alpine, bolts are a feature of the climbing landscape. But not all bolts are created equal. This article from our ‘Nuts & Bolts’ series, aims to run you through what to look for when clipping bolts, how to spot a bad one and what to do if you encounter bad bolts.

This article will cover:

• Different types of bolts and how to identify them

• Common problems

• Potential fixes and solutions

Types of Bolts

Mechanical Bolts

Globally, mechanical bolts are probably the most common bolt rock climbers will encounter. Such bolts are also common on single pitch traditional routes, as well as alpine and multi-pitches with ‘trade route’ status.

Mechanical bolts are available in a varying lengths and alloys, with a diameter of either 10mm or 12mm. Not all mechanical bolts are manufactured specifically for climbing, and encountering one on a route does not guarantee the manufacturer ever intended for it to be used there.

All mechanical bolts function by the sheath expanding and gripping the rock within the drilled hole when loaded. The idea being that the gripping force exerted when loaded is less than the compressive strength of the rock in which it is placed, and so the bolt holds the fall. Unfortunately this is not always the case, especially in softer rock types, where the compressive strength of the rock is low. This results in bolts pulling out. As such on softer rock types, chemical bolts are preferred.

Chemically Bonded Bolts

Originally designed for the construction industry, chemically bonded bolts quickly gained popularity for offering a more secure bolting solution, exerting force over the full length of the bolt with no moving parts when loaded and reducing total stress exerted on the rock. Chemically bonded bolts also have a far longer lifespan than mechanical bolts, with well placed bolts projected to last up to, and in excess of 100 years.

Early designs are weaker than modern counterparts, which seek to add some mechanical advantage to the bonding chemical by an external structure/notching on the shaft which keys into the adhesive.

There are found main types of chemically bonded bolts:

• Bent Rod Bolts

• Forged Eye Bolts

• Welded Eye Bolts

• U-Bolts/Staples

Bent Rod, Forged and Welded eye bolts will be near indistinguishable to most contented bolt clippers. However, U-Bolts/Staples are easily identified and present some of the most interesting fodder for discussion.

U-Bolts/Staples

U-Bolts/Staples are near ubiquitous on many softer Sandstones, and common in marine environments.

Virtually all the staples you clip will be home made, and are formed from a bent steel bar of differing thicknesses 8mm-12mm. FIXE did produce U-Bolts for a number of years, however have now ceased production of their product. Titan Climbing still manufacture titanium staples, however your chance of spotting one in the wild is rare.

Home made staples vary not just in the alloy used and the degree it is bent through, but also in the amount of notching on the two shafts. Early designs, were left un-notched and this lead to bolts pulling out at unsuitably low forces.

U-Bolts do require a greater degree of consideration when selecting where to drill, since two holes lying relatively close to each other need to be drilled. It is also possible for carabiners to un-clip themselves if the staple’s geometry is wrong. More on both of these problems later.

Self-Drilling Bolts/Spits

Thankfully becoming a historical curiosity, self-drilling bolts were once the bolts of choice for anyone putting up routes in the alpine, or hard wall ascents, being light and relatively quick to drill by hand.

There is some variation between manufacturers, but generally these bolt are 8mm-10mm in diameter sunk to 20mm in the rock. Placements are weak, with pull out forces ranging as low as 3kN, and in poor rock where full expansion may not be possible will be even lower. Self-drilled bolts are often very corrosion prone, due to the combination of different alloys used in the system. This isn’t helped by the fact that they are then usually placed in harsher environment than the average bolt on a sunny sport route. The all too common result is heavily corroded hardware, sheared off hangers and/or completely disintegrated bolts. Scary stuff, especially since you often won’t know the full extend of the corrosion beneath the surface.

Problems

Bad Drilling

Some areas, such as Tonsai in Thailand, now benefit from near professional development efforts which ensure a baseline standard in competency and quality of equippers. However, many do not and although developers are generally drawn from a small cohort of competent individuals, there’s no guarantee this is this case.

If you can identify a route which is potentially poorly bolted before you jump on it, it may just save your life.

Potential clues to identify bad drilling:

• Weird Lines - Does the bolt line resemble an Etch-A-Sketch up a straight obvious line of climbing?

  Not necessarily a damning sign, but potentially indicative of an inexperienced equipper. Would you trust your life saving operation to the work of a messy surgeon or a tidy surgeon?

• Runouts - Are there sudden uncharacteristic run-outs on an otherwise safe route?

  Dangerous in their own right, runouts are potentially indicative of an equipper who’s not got their eye on the ball or doesn’t know what they’re doing. This is not always the case though, some routes are runout by design, consider Rock Warrior on Red Rock’s Black Velvet Wall.

• Poorly Placed Bolts - Are the bolts placed in suspect location, right next to small surface cracks, hollow and loose rock, or a staple placed over a pocket?

  Bolts are reliant upon the compressive strength of the rock they are placed in. Competent developers will always seek out stronger not weaker rock.

  For specific advice on bad rock, see below.

• Bolts placed close to lips - Are bolts placed close to the lip of roofs or near the edge of prominent flakes and cracks?

  The compressive strength of the rock is typically weaker close to these features. Look for a uniform rock surface, which lacks surface cracks and ensure a hand’s width (>200mm) or greater from any flakes, arêtes or lips.

  Such bolts, can also incur the second problem of being ‘carabiner breakers’, if they are placed such that the spine of the carabiner lies over the edge. When loaded the spine of the carabiner will be subject to abnormal load, and can break. Generally speaking, experienced developers don’t drill ‘carabiner breakers’.

• Protruding Bolts - Do the bolts appear fully sunk and do the hangers sit flush against the wall?

• Non-Standard Bolts - Do you recognise the type of bolt used? Is it consistent with the choice of hardware in the rest of the area? Responsible developers will use recognisable branded hardware, that appears congruous with the rest of the area. On mechanical bolts, ensure all parts are made from same alloy by the same manufacturer.

  DIY skills are great, but your ability to fix a bookshelf doesn’t gamble on the lives of strangers. Approach non-standard hardware with extreme caution. More often than not they’re ticking time bombs, some having life spans of less than 10 years.

In addition to these visual clues, a good local guidebook should alert readers to any questionable routes.

Bad Rock

Even a well placed corrosion free modern mechanical or chemical bolt is only as good as the rock it is placed in.

Commercial bolts from manufacturer such as FIXE or Petzl are tested in concrete which is both stronger and more uniform in quality than rock. The compressive strength of rock varies between rock types as follows:

• Granite: 1,800kg - 18,000kg

• Sandstone (excl. very soft sandstones): 450kg - 9,000kg

• Limestone: 450kg - 5,000kg

If the bolting in an area is good, generally the bolts were placed in sound rock. However, crags are active places. Beneath its patina, the rock is usually softer. Drilling a bolt can create micro-fractures in the rock which lie hidden beneath the surface. Look for ‘spider web’ cracking around bolts and crumbling. Once sound placements, can change and fail.

This is true even more so in alpine areas or places with more extreme weather events. In such environments, processes of weathering can and will break apart the rock rendering once sound rock poor.

If you find a bolt to placed on what appears to be a block, test the block. Is there movement vertically or laterally? Does it make a hollow sound when struck? Blocks may be ‘keyed in’, but always clip with hesitation. If the block is loose or hollow sounding, do not clip it. You wouldn’t pack cams in behind a suspect loose block would you?

If the bolts are sound, but there is much surrounding loose rock, consider using extended quickdraws so the rope runs away from loose rock. It may also be prudent to refrain from clipping certain bolts if it would keep the rope away from areas of particularly chossy rock. Have your belayer seek a sheltered position out of the fall-line of any loose rock, and consider carefully if it’s really worth/necessary to climb a loose pitch. If you come to this realisation mid-pitch and decide you want out, see our Fixes section below.

Corrosion

With the exception of some antiquated homemade aluminium hangers (beware, these are very prone to exfoliation corrosion), most bolt components are fashioned from steel.

Carbon manganese and alloy steels are cheap, and corrode uniformly. Such steels may be zinc-plated/galvanised to increase their lifespan. Stainless steels are preferable, with grades 304 and 316 being the two standard choices for bolting hardware. 316 series steel is the most appropriate for marine environments.

Galvanic corrosion occurs when differing alloys are used resulting in one component corroding in favour of another. Such that, the corrosion rate of the less resistant metal increases whilst that of the more resistant metal decreases.

The extent to which this is a problem has been questioned by some. Anecdotal evidence has suggested it to be more of a problem for bolts placed in environments with a high presence of sulphur compounds. For example, sea cliffs or certain valleys in the European Alps with bad air quality. But there is also anecdotal evidence to the contrary. Generally ‘mixing metals’ is bad. Look for consistent hardware from the same manufacturers on a bolt, and view a shiny hanger with a corroded nut with caution.

Atmospheric and freshwater corrosion also affect bolt quality. Atmospheric corrosion occurs due to the presence of air (oxygen) and moisture. The process is exacerbated by atmospheric contaminants. Freshwater can be rendered more acidic by pollutants and acidic soils above and on the rock face, or become more alkaline if seeping through a limestone.

Some corrosion need not be a cause for concern. However, unfortunately the true extent to which a bolt is affected by these types of corrosion is hard to tell, since the bolt hole is the most damp place the bolt is in contact with.

Uniform corrosion is the easiest to spot and occurs equally over the surface of an alloy component or galvanised component which has lost its zinc coating. It will continue until the alloy wears thin and fails.

Pitted corrosion occurs in stainless steel components and is more troubling. Pitted corrosion presents as a small area on the surface, often this will affect deeper and wider areas of the component under the surface. Developed pits or closely groups pits can form crevices which will further corrode and lead to bolt failure.

Stress Corrosion Cracking (SCC) is a phenomenon affecting stainless steel bolts in hot humid conditions in the presence of sea water. This has been the driving force behind the development of the Thaitanium project, to replace Tonsai’s dangerous old steel hardware, with titanium chemical bolts. There is little evidence to suggest it occurs below ~50C/122F, so for climbers in most parts of the world this is not a concern.

Steel glue in bolts are not necessarily less susceptible to corrosion than mechanical bolts. The shaft of an apparently sound glue in bolt can still be corroding inside the bolt hole if exposed to air.

Hanger Issues

Besides badly damaged hangers which are covered in the fixes section, the four main hanger problems are:

• Spinning Hanger

• Badly Oriented Hangers

• Carabiner Breakers

• Worn Bolts

If you encounter a spinning hanger, try to identify whether it is due to the entire bolt being loose in its drilled hole, or just the tightening nut which is loose. Providing it is the latter, tightening it with your fingers should be sufficient to get you safely to the top of your pitch. If it is a long term project, or you are likely to be taking repeated falls then it is worth tightening the nut with a wrench. Failure to do so, could result in the hanger rotating such that it is badly oriented, triggering the second problem.

Badly oriented mechanical bolt hangers which face directly down the pitch rather than perpendicular to it. Such hangers can allow the bolt-end carabiner to rotate with the action of the rope, and from here un-clip itself. To help prevent this, ensure your quickdraws are unopposed and clipped such that the gates face away from the direction of travel. See our full article on it here.

‘Carabiner breaker’ bolts are not technically a hanger problem, but are solved from the hanger end. To avoid a your carabiner’s spine lying in a vulnerable position, girth hitch/larks foot a short sling to the hanger and clip this. Ensure the new extension clears the edge in question.

Staple/U-Bolts which have an inappropriate bend angle can similarly un-clip if the rope action drags the bolt-end carabiner around through itself. If you suspect the staple has bad geometry, rotate the top carabiner through with your hands to test this. If it is able to rotate and un-clip, swap out the top carabiner for a locker, or double up and oppose quickdraws on that bolt.

Chemical bolts which are regularly lowered through, either at the top of a pitch, or before/after a cruxy sequence which climbers may choose to retreat from can become excessively worn. Bolts which are beginning to wear more than a third of their diameter should be treated with caution. In extreme cases it may be better not to clip them, use a clip stick to clip the bolt above if required and possible.

(And remember, never attempt to lower through an expansion bolt hanger like you can a chemically bonded bolt!)

Bolts that Move

Bolts which move on any plane (side/side, up/down, in/out) should be treated with extreme caution. It may be that this movement is minimal and little cause for concern, but it is not the best idea to test this theory with your life.

Movement can be the result of excessive corrosion, unset/deteriorating glue, or poor rock quality. For solutions, see the Fixes section below.

Fixes

We have already touched on a few quick fixes:

• Bolts placed near areas of significant loose rock: Use extended QDs.

• Spinning hanger: Finger tighten the nut.

• Worn chemical bolts: Do not clip and/or stick clip up to the next bolt.

However, more serious problems demand more complex fixes.

When encountering a suspect bolt, the first decision you need to make is whether to go up or down. In the case of single or multi-pitch sport climbing, the answer should be obvious. On traditional routes, you may feel comfortable supplementing bolts with leader placed protection. But if the route relies on bolted belays and bolt protected sections and you’re running up against bad bolts, then the answer should again be obvious; -get off, get down and get a pint.

Fixes become more complex and desperate in scenarios where it may not be possible to reach the ground, and topping out is the only option.

Retreating Mid Pitch

To retreat mid-pitch, your options are:

• Rappelling

• Being Lowered

• Belayed Downclimbing

If you are climbing on a single rope and out more than half a rope length, you will have to do a multi-staged descent.

Rappelling (providing you are competent and can rappel smoothly) will place less stress on the gear than lowering. Many single pitch sport climbers do not carry descending devices when climbing, but if you’re climbing routes with suspect bolts or little information, it is always worth carrying something. A CAMP Ovo or Kong GiGi, combined with a short length of 5mm cord girth hitched to your chalk bag strap provide light weight solutions.

If descending at a single suspect bolt with sound protection below, and provided you trust this bolt to hold body weight, you will want to either ‘back-up’ or ‘beef up’ the bolt for descent.

For those carrying traditional protection, ‘beefing up’ the bolt with one or two further pieces equalised on an anchor should allow you to descend and clean the gear below on your descent.

Those only climbing with a sport rack, have your belayer lower you, and keep the bolt below you clipped as a ‘back-up’. There is no need to leave quickdraws, use a maillon on the top bolt and a taped shut snap gate on the back-up bolt.

If you do not trust the bolt to hold body weight and cannot build a gear anchor, you will need to down climb on belay to your last good piece. Here, you can go into the piece direct, pull your rope, and descend from this sound protection by rappelling or lowering.

But I Need to Climb On…

Sometimes the fastest, or only way down is up.

But consider if this is really the case. Could a reasonable descent by standard methods be contrived? If the answer is yes and you’re looking at sustained climbing over a number of pitches of ‘mystery’ hardware which could kill you, then the difficult but safe option should be preferred.

The art of the upward bail is dicey at the best of times, and if you’re dealing with heavily corroded hardware, there is no guarantee any technique will save your skin, but there are certainly things you can do to stack the odds in your favour.

We’re assuming in such cases climbers will be carrying some traditional gear, and so reference is made to this throughout. The likelihood also is that climbers will be encountering a wide variety of mechanical and self-drilled bolts all of which have hangers so reference is made to these.

Corrosion Fixes

If the bolts are heavily corroded but there is not significant movement in the bolt hole, and the eye or hanger is intact, ‘beef up’ the piece with additional equalised protection to form a subsidiary anchor. Lots of bad/marginal pro, is better than no pro. Thread the corroded hanger with a girth hitched sling, rather than clipping it directly with a carabiner. If you have the luxury, clip it with an old style nylon Yates Screamer of comparable product such as a DMM Nylon RipStop.

It is also possible, that some hangers will not be intact, but there is not significant movement in the bolt hole. Shearing is common on many self-drilled bolts with aluminium hangers. Hangers may also not be fully intact due to corrosion. Sometimes hangers may have been hammered down to render them un-clippable.

In any one of these cases thread behind the hanger if possible with 6mm-8mm dyneema, it’s flat profile being preferable to cord, girth hitch it and turn the hanger to synch down on the dyneema. Alternatively you can use a small to medium nut cable behind the hanger and synch down on the bolt using the nut. Depending on the state of the hanger, the size of the nut and thicknesses of the cable needed will vary. Slim profile micro-nuts such as DMM Micro Wallnuts work particularly well. If possible, ‘beef’ this up with further pieces, equalise them to form a subsidiary anchor, clip it with a screamer or similar and climb on; gingerly.

Fixes for Bolts that Move

In the direst straits, it may be that there is significant movement ‘in/out’ of the bolt hole. Providing the bolt is well placed, it may be that in the event of loading, you would be loading the piece perpendicular to this ‘in/out’ movement. You can use this to your slight advantage. Although, when you’re rolling the dice this much, terming it a ‘slight advantage’ is a cruel euphemism.

Utilise the in/out movement to pass some 6mm-8mm dyneema behind the hanger, girth hitch it, then turn the hanger if possible to synch down on the sling. Alternatively you can use a small to medium nut cable behind the hanger and synch down on the bolt using the nut. Depending on the state of the hanger and bolt, the size of the nut and thicknesses of the cable needed will vary..

Clip an extender to the sling/cable, to reduce the effect of the action of the rope, then if you have the luxury clip a Screamer or similar. You are relying on the torque created by loading the bolt perpendicular to the drilled hole to hole, so it is worth clipping some gear or something to weight the sling/cable down in the correct direction. Ensure, this weights the bolt perpendicularly down, not out, as the latter would have the effect of pulling the bolt out!

But I Need to Descend on Bolts that Move

Adopt similar principles for rappelling on such bolts. ‘Beef up’ if at all possible, combined bad gear is better than no gear. And become comfortable with leaving gear behind, yes it might be £10/$10, but that’s probably the cheapest life saving purchase you’ll ever make.

Apply a consistent smooth load perpendicular to the drilled hole. If at all possible for rounded lips, ledges or bulges to take some of the load as you rappel over them let this happen, provided they are not ‘rope slicingly’ sharp.

Rappelling on such bolts is a last resort. If belayed down leading and belayed down following is possible on that terrain and with suitable protection opportunities, then climbers should select this strategy over rappelling.