fall arrest systems: Dynamic tests as a basis for monitoring and training

Dynamic, biomechanical tests and
videos made in Switzerland in 2009

www.isfp.com / June 16th 2010 Baltimoore / bernhard.vonmuehlenen@suva.ch

Content

The aim of this presentation is to show:

 Sample videos and illustrations of physical impacts
to the human body when arrested in a non-upright
position by a fall-protection system

 How to support training facilities

 Starting with a "Opensource"-Project for
fallprotection training

www.isfp.com / June 16, 2010 Baltimore / bernhard.vonmuehlenen@suva.ch

The situation in Switzerland (1)
.. not just watches, chocolate, banks in trouble & fine cheese

 We are a small country (population: 7.8 millions)
- 230 times smaller in area and 40 x fewer inhabitants than the USA

 excellent accident-prevention regulations and laws
- No scope for any misunderstandings in global but lack of details

 Suva (Swiss National Accident Insurance Fund)
- is responsible for all companies operating in high-risk areas

… more than just a insurance fund:

 prevention, monitoring, insurance & rehabilitation
under the same roof


.. not just watches, chocolate, banks in trouble & fine cheese

 Very Multi-Multilingual culture

- 4 official languages (Swiss-German, French, Italian & Rumantsch)
and real strong local dialects

- About 60% of employees on construction sites having a migrational
background (Portuguese, Spanish, Italian, Serbo-Croatian,
Albanian, Turkish etc.) = lack of knowledge of the local dialect


mandatory by law:

 Guardrails / edge-protection-systems, Scaffolding and
safety nets are compulsory when working at heights
greater than ~ 9 feet (3.0 meters) above the ground

 PPE / personal fall protection is only permitted when the
use of scaffolding, safety nets, mobile elevating work
platforms, etc. is technically impossible or too dangerous
to attempt

 That’s why the use of PPE when working at a height is
called:
“the worst of all less than optimum solutions”

Nets for road / railwaytrack protection



But:

 ~ 1/3 of accident fatalities or disabilities are caused by
people falling from a height!!

 … and there is still an enormous number of real small
companies (< 5 workers) that are unaware of
fall protection


Construction site was closed down
immediatly:

9

some of them even try hard….

10

"… I never thought about..."

2010 - Fallprotection for engineers - Haan / Germany / bernhard.vonmuehlenen@suva.ch

He knew, that there is a certain risk

2010 - Fallprotection for engineers - Haan / Germany / bernhard.vonmuehlenen@suva.ch

August 19th, 2009 44 feet / 13.50 meters  
5 hours later, another roofer was preparing to climb the roof to repair it
– and he had left his PPE in his car!!

13.50m

Why carry out tests with instrumented
crash-test dummies?

 We had no video sequences showing common
construction-site situations with falls from a height

 We had no idea of the forces and accelerations
involved when a fall from a non-upright position is
arrested by PPE

 We needed a way to make direct comparisons
between the different types of fall-protection
equipment and systems


Our instrumented crash-test dummy (1)
Crash-test dummy
 HIII 95% ATD (anthropomorphic test device) • Modified HIII 95% male ATD with a
pedestrian pelvis, mass of 100kg ( 220lbs)

Head & neck module
• Triaxial accelerometer (x, y, z)
• Triaxial gyroscope (x, y, z)
• 6-channel upper-neck load cell
(Fx, Fy, Fz, Mx, My, Mz)

Chest & lumbar spine cell
• Chest deformation sx
• Lumbar spine Fx, Fz, My

Pelvis cell
• Pedestrian pelvis of a HIII 50% ATD
• Triaxial accelerometer (x, y, z)

04.08.2009

Our instrumented crash-test dummy (2)

 HIII 95% ATD (anthropomorphic test device)
M = BUS (Messring Systembau GmbH D-Munich)
• Recording frequency: 20 kHz
• Duration of recordings: max. 17 seconds
• The data is stored by loggers directly from the sensor
•The ADT can be operated by wireless  no cable impact on event kinematics
•Connection between the individual loggers can be interrupted during the tests without any loss of data

M = BUS communications unit with a Dummy system of coordinates
rechargeable battery

04.08.2009

“The man” - white rope is the backup rope

17

Pendulum fall against a scaffolding pole
 more than just a headache

 Regulations/limits
- WRAIR
- ECE-R94 (Link)
- Directive 2003/102/EC
- FAR-25.642
- WTD 91-440e

18

One more crushed helmet


Conclusion of ADT tests in 2009

 While most of the results did not represent a dummy
“fatality”, even the film sequences looked shocking

 The experiments were not reproducible
a fall is always a unique movement
 Results are not a exact science

 It is important to make people understand that the
proper use of PPE may prevent fatalities caused by
falls to the ground, but the danger of injury remains
 Promoting the use of restraining systems in
training

Benefits & Risks

Benefits
 Videos help to visualize the forces behind physical

impacts on a human being, specially in a
multilingual country like Switzerland
 Slow-motion video makes it more comprehensible

 You can even watch it on your cellphone

 It is often too time-consuming and too dangerous for

live, on-site demonstrations - videos help

Risks
 Videos can be quite frightening – can they alienate?


How can we make the risk of high shock
loads and accelerations understandable?

 By using more shocking videos?

 By using shocking images?

 With self-experiments? (each one jumps himself)
 Difficult to understand but easy to feel?

 = Confucius (450 B.C) freely interpreted
– Tell me, and I will forget.
Show me, and I may remember.
Involve me, and I will understand. (Confucius, 450)
– Let me feel it and I will never forget! (Bernhard 2010)


Possible self experiments

1. Jump up 2 inches and land on your heels with
stiff knees (no energy absorbed)

2. Pendulum fall against a plank (both can feel it!)

3. Shockload with and without shockabsorber


He really thought that it's all right


Everydays nightmare


Suva fallprotection training concept
(introduced in spring 2010 -duration 1 day at least)
Theory
included in
practical part

Training- Tools &
Posters for training-
training-centers proposals

background- Short Video-
information sequences


Opensource website
for fall-protection training
www.absturzrisiko.ch www.fallprotection.ch
www.antichute.ch www.anticaduta.ch

 Learning / training units (booklets & posters)
 Tools for training-administration
 Vector graphics (*.svg) for your own posters
 Videos (30-60 seconds each on a specific subject)
 Products (new & unknown ones)
 Services like training site safety, colaboration etc.
 FAQ's & eLearning

 Still growing & being translated

A microsite for its own
www.absturzrisiko.ch / www.fallprotection.ch / www.antichute.ch / www.anticaduta.ch


Further videos on YouTube

29
..like worksafe BC (Canada) is doing it excellently

Networking & live demonstrations


 Any questions?

 E-mail: bernhard.vonmuehlenen@suva.ch


fall arrest systems: Dynamic tests as a basis for monitoring and training

Recommended

Recommended

More Related Content

More from Senn AG

More from Senn AG (6)

fall arrest systems: Dynamic tests as a basis for monitoring and training