Climbing Protection - Choosing the Right Equipment
Choosing and placing protection is a key skill that must be mastered if you are considering leading trad (traditional) routes.
Protection is a generic term for the equipment that a climber places in the rock to act as a temporary anchor point in the event of a fall. There are three main types of protection:
- Slings
- Passive Protection - wallnuts, wires, nuts + hexes.
- Active Protection - camming devices.
1. Climbing Slings
These are normally commercially manufactured from high strength tape that is sewn into an open loop sling with multiple bar tacks binding the two ends together. The slings are used by climbers in two ways - used as a direct anchor by being threaded through or around rock features or being used as a connector to extend a safety system.
The most common slings carried by climbers today are generically referred to as "dyneema" slings. Dyneema is the registered trademark name of an Ultra High Molecular Weight Polyethylene (UHMWPE) fibre that is manufactured and licensed by the company DSM. There are other producers making very similar UHMWPE fibers with different trade names - Honeywell's Spectra being a key example.
Slings that use UHMWPE fibres in their construction have gained in popularity because of their low weight and bulk combined with high tensile strength. UHMWPE slings used in climbing always have a second component - normally nylon - that is used to add durability to the finished product. Dyneema fibres are very hard to dye and so the vast majority of dyneema thread is white in colour. Thus when you look at a dyneema sling the coloured fibres are nylon (very occasionally polyester) and the whites fibres are dyneema.
The other main material used for making climbing slings is nylon.
Each material has advantages and disadvantages.
Climbing slings sold within the EU countries have to be able to hold a force of 22kN as defined in EN566:2007. Nylon tape can not hit this minimum value consistently unless it is 15 -16mm wide, whereas dyneema slings can meet this value at widths as low as 6 - 8mm; thus dyneema slings can be dramatically narrower, lighter and more compact than a nylon sling with equivalent strength. A narrow sling allows the climber to thread it through narrower constrictions / gaps and this is a considerable advantage.
Durability of any sling will depend on the exact composition of its fibres and how those fibres are woven together, however it is fair to say that nylon slings are generally more durable than dyneema slings - resisting abrasion better and being more resistant to fluffing/pulled threads. Always look for a nice tight weave on skinny slings.
The other disadvantages with dyneema / spectra slings are mainly related to their physical properties that makes them less tolerant of user error / poor practice.
These properties are the relatively low melting point of UHMWPE fibres (144 - 152 degrees Celsius), low friction (similar in value to Teflon) and an innate inelasticity.
Low melting point is often cited as a disadvantage of dyneema, however you would need to be fairly dumb to get a failure caused by melting. Key things to avoid would be using dyneema slings as prusics ( they wont work very well either) and avoid larks footing skinny dyneema slings and then bouncing on them directly or indirectly via a top rope system.
The low friction of UHMWPE fibres leads to poor knot-holding ability so don't ever think about constructing your own dyneema sling - even with a super-duper-ultra safe knot. It will unravel when you least want it to.
The innate inelasticity of dyneema means that it does not take well to being shock loaded - i.e. avoid building direct belays using dyneema slings and especially don't 'shorten' them with an overhand knot or two.
The most common lengths of slings carried by climbers are:
1. 60cm (4ft) - These slings have a linear length of 60cm and a circumference of (about) 4 feet and you will often hear them being referred to by both names. This length of sling is great for extending runners on long pitches and for connecting yourself quickly into anchors before setting up the main rope belay. Very skinny versions of this sling are brilliant for using as extendable quickdraws.
2. 120cm (8ft) - Probably the most popular and overall most useful length. Great for rigging belays, slinging over spikes and generally linking items together.
3. 240cm (16ft) - Really useful for setting up belays, but generally too long to haul up routes.
2. Passive Climbing Protection
These are normally aluminium or soft metal wedges attached to a loop of steel wire/tape/cord that are placed in narrowing cracks or restrictions in the rock face. Nuts are manufactured in many different varieties.
They are often referred toas wires and nuts.
There are 3 general groups:
- Micros - RP's, DMM IMP's and BD Swedges
- Standard - DMM Wallnuts, DMM Offsets, WC Rocks and Metolius Curve Nuts.
- Large - Hexcentrics (Hexes), WC Rockcentrics and DMM Torques
a. Micros: These are the smallest nuts in a climbers arsenal, they are generally weaker than larger nuts because they can only be threaded/connected to thinner and, hence, weaker wire. They are invaluable in protecting harder climbs because they fit where nothing else will go.
Micros are either manufactured by silver soldering a 'brass' nut onto a stainless steel wire or swaging an aluminium alloy nut onto a steel wire. There is a lot of nonsense bounced around about silver soldered nuts being a lot stronger than swaged nuts - most of which is either exaggerated or based on falsehoods. The ultimate strength of a nut in a laboratory environment will depend on the thickness of the wire used - the thicker the wire the stronger the nut. On any given size of nut there is maximum size of wire that can be inserted into it - no matter whether soldered of swaged.
Add to this the fact that standard steel wire as used on swaged nuts has a higher tensile strength than the stainless steel wire that must be used on soldered nuts.
Thus an examination of rated strengths shows an equivalence between soldered and swaged nuts. The RP nuts generally are rated higher than other brands, but based on a knowledge of stainless steel wire strengths it may be that these strengths are based on mean rather than 3 sigma strengths. The RP 2 however is a clear winner - the ability to put a 2.0mm wire in a nut head of this size make the nut very strong compared to everything else.
Model |
wire diameter (mm) |
width of nut (mm) |
depth of nut (mm) |
kN - marked rating |
DMM Peenut 5 |
2.50 |
13.9 |
9.6 |
8.0 |
BD Swedge 6 |
2.90 |
10.5 |
8.9 |
8.0 |
DMM Peenut 4 |
2.50 |
13.4 |
8.8 |
8.0 |
RP 5 |
2.50 |
11.4 |
8.7 |
8.2 |
DMM Wallnut 2 |
3.45 |
15.6 |
8.2 |
9.0 |
RP 4 |
2.50 |
9.3 |
8.0 |
8.2 |
BD Swedge 5 |
2.50 |
9.6 |
7.5 |
6.0 |
DMM Peenut 3 |
2.00 |
12.8 |
7.4 |
5.0 |
DMM Wallnut 1 |
2.50 |
14.0 |
6.6 |
7.0 + 4.0 |
DMM Peenut 2 |
2.00 |
11.8 |
6.4 |
5.0 |
RP 3 |
2.00 |
8.0 |
6.2 |
5.5 |
DMM MW 0.75 |
2.50 |
12.8 |
6.0 |
6.0 |
BD Swedge 4 |
2.50 |
8.6 |
6.0 |
6.0 |
DMM Peenut 1 |
2.00 |
11.6 |
5.7 |
4.0 |
BD Swedge 3 |
2.00 |
7.5 |
5.2 |
5.0 |
DMM MW 0.5 |
2.00 |
11.6 |
5.2 |
4.0 |
BD Mini 2 |
1.65 |
10.7 |
4.8 |
2.0 |
DMM MW 0 |
1.50 |
10.7 |
4.6 |
2.0 |
BD Swedge 2 |
1.75 |
6.6 |
4.4 |
3.0 |
RP 2 |
2.00 |
6.6 |
4.4 |
5.5 |
BD Mini 1 |
1.65 |
9.0 |
4.1 |
2.0 |
DMM MW 00 |
1.50 |
9.6 |
4.0 |
2.0 |
RP 1 |
1.00 |
5.3 |
3.6 |
3.6 |
BD Swedge 1 |
1.30 |
5.0 |
3.2 |
2.0 |
The best micros currently available are RPs - small brass nuts with a slight, fairly regular taper that are silver soldered onto stainless steel wire. RP's were the designed by Roland Pauligk in Australia and every brass nut is still meticulously crafted by Roland in Australia. They don't have a CE certificate and so can't be sold in Europe, but sizes 2 + 3 are invaluable to any extreme leader.
BD Swedges are OK, but their high hardness (90 Rockwell) means they just don't bite into marginal placements as well as RP's (70 Rockwell), plus their wire is too stiff and can lead to them being dislodged more easily.
DMM will have a couple of ranges of silver soldered micros available in 2009 and these look good - I have been using these DMM IMPs for the last 3 months and they are every bit as good as RP's.
The swaged micro nuts (i.e. DMM Micro Wallnuts) offer greater, surface contact which is an important consideration as a common mechanism for failure in real life is the nut pulling through the placement. Once again the devil is in the detail - using a stronger 7075 aluminium alloy nut as on the DMM Micro Wallnuts gives extra holding power compared to a softer 6000 series alloy.
Micros in the greater scheme of things are relatively weak (2kN to 8kN), so always try to place them in clusters, tell your belayer to give a soft, dynamic belay in the event of a fall and use a nylon ripstop/screamer to slow down/limit the load applied to the nuts. ( Dyneema ripstops are pretty useless - they can't absorb enough energy - use nylon ripstops, but be aware that even they have a limit to the amount of energy they can absorb)
These are the mainstay of any climbers arsenal so choose wisely because although the may look similar there are significant differences in how they perform.
In general these nuts are manufactured by swaging alloy nuts onto steel wire. The shape of the nut head, the thickness of the nut walls, the alloy material used and the thickness and construction of the wire will together dictate the overall performance and characteristics of the nut.
In general the basic, slightly tapered wedges should be avoided - they just don't sit well in a lot of placement.
In my opinion the best nuts on the market at the moment are:
i. DMM Wallnuts - Great shape that allows really versatile placements, but also makes them harder to clean...but then that's the seconds problem and stopping a fall is the main priority. They are also light.
ii. WC Rocks - The other main nut used in the UK - good all round shape. The 'Classic' rocks should be avoided - horrible, heavy copies of the real thing.
iii. DMM Offsets - The biggest surprise in existing equipment for me in the last 10 years - a totally brilliant shape that works so, so well - based on the HB design and a good reminder of the genius of Hugh Banner. It is just a pity that there are only 5 sizes.
iv. Metolius Superlight Curve Nuts - great nuts that work really well.
The Zero G and BD nuts are pretty average - basic shapes that really limit placement options and with bendy wire that makes over-head placements difficult on the larger sizes.
UK climbers usually choose Wallnuts or Rocks as their first set, but the key thing with these mid-size nuts is maximising placement options so always try to bring variety into your rack of passive protection. Thus if your first set of nuts is Wallnuts then, perhaps, choose Rocks as your second set and then supplement these with DMM Alloy Offsets or Metolius Curve Nuts.
The best large nuts are currently Wild Country Rockcentrics on dyneema and a small collection is really useful, especially when you are starting out and have a limited selection of medium or large cams.
The new DMM Torque will be good when they are released in Mid 2009 as they lock /cam into placements better, cover a wider size range per unit and can be fully extended using an integral double sling.
Large hexcentric nuts on wire are not as good as those on dyneema because they tend to lift out of placements more easily.
The old style, classic Camp Hexcentrics work well, but are a bit heavy and need to be self-slung on accessory cord.
There is more on large hexcentric nuts and how to use them effectively on the Learn to Lead Climb in Spain page
