The Evolutionof

Climbing EquipmentStandards

finch images from Charles Darwin’s Voyage of the Beagle

Dave Custer

American Alpine Club/Alpine Club of Canada Delegate to theUIAA Safety Commission

CWA Engineering Standards Committee MemberMIT Lecturer

April 13, 2007 CWA Summit, Climbing Standards Evolution

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are standards for the birds?

• climbers

• equipment manufacturers

• gym owners & operators

• safety folks

• regulation folks

• me

April 13, 2007 CWA Summit, Climbing Standards Evolution

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a history of climbing equipment standards

the physics behind climbing standards

examples of radiative adaptation in climbing

a peek at where gym climbing standards might go

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• accidents• marketing• demographics• climbing developments• developments in related sports• research• assorted climbing organizations• government regulation

causes of equipment &/or standards evolution

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deep history

• not many climbers• not much standardization• no money to be made• it was a stupid sport anyhow

very similar to the aid climbingscene today.

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more climbers, accidents, & $$$, lead to more attention to standards

research and standards effectively reduce “equipment failure” to zero.

• mid 60s, rope testing• early 70s, UIAA safety commission• 70s and 80s, research & standards• 90s CEN, ASTM, etc.

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research

busted gear images from DAV Sicherheitskreis Taetigkeitsbericht 1980-1983

with research, inadequate equipmentbecomes extinct quickly.

0 1 2 3-1

time, s

0 1 2 3-1 0 1 2 3-1

time, s

-5

10152025

3035

-40 -30 -20 -10 0 10 20 30 40Placement Angle, Degrees

Failu

re L

oad,

kN

WI-S WI-FAI-S AI-FHarmston LuebbenDAV/OAV WI-S Long

(b)

best practices become apparent.

April 13, 2007 CWA Summit, Climbing Standards Evolution

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standards organizations

UIAACEN PPE directive (CE)ASTM/ANSI/ISOCWA(REI)

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equipment standards(individual components of the safety system)

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systems theorymakes pin the blame onthe victimmore difficult

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image from American Alpine Club Journal, 1950

physics basis for standardsclimbers can tolerate ~10 G deceleration(18 G permitted on US Navy pilots duringparachute deployment)

the Earth’s gravitational field is 1 G (9.8 m/s2)

safe fall arrest distance lies between1/10 of fall distance (physics) and 1/5 fall distance (UIAA/CE dynamic rope standard)

( )mgMFmgT

kymgymgh

211

221

++=

=+

April 13, 2007 CWA Summit, Climbing Standards Evolution

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where the energy goes during fall arrest

April 13, 2007 CWA Summit, Climbing Standards Evolution

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Maegdefrau Datasqrt fall factor vs.

anchor load

0

2

4

6

8

0.00 0.50 1.00

sqrt fall factor

anch

or lo

ad (k

N)

Single Rope

Rope Pair

data from Helmut Maegdefrau’s PhD thesis

theory, experiment, and standards match well

95% of falls put less than 7 kN on the topanchor (minimum permitted open gate carabiner strength).

20 kN forces onanchors requireinappropriate useor a very, very badkarma (20 kN is the minimum closed gate carabiner strength).

April 13, 2007 CWA Summit, Climbing Standards Evolution

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equipment still fails

Carabiner failure images from 2005

UIAA SafeCom meeting minutes

misusefatigueoveruseabusemodificationchemical abuse

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ice ax standards

current ice ax standardsare based on the demandsof mountaineering

B and T blades?shaft strength?

the remedy will be slow,probably by intended use.

image from Grivel web site.

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via ferrata

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via ferratastandards

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lessons from standards history

Standards evolve.Standards are based on research & “physics”.Standards prevent equipment failure accidents.The evolution is slower than the evolution of the sport.

Expect:Standards development to follow new climbing developments.Increased standardization of safety systems.Increased standardization of best practices for safety systems.

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wild prediction: belaying will become a sport

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best practice examples