Transcript Slide 1

AN INVESTIGATION INTO
FALLS OVER OR FROM THE SIDE OF ESCALATORS
By
David Cooper
BSc(Hons), MSc, CEng, FRSA, FIET, FCIBSE
• Between 2000 and 2005 I took an MSc at the
University of Northampton, UK
• My dissertation subject was an investigation into
accidents on escalators involving shopping
trolleys and luggage carts
• During that research it became apparent that
there was a problem with passengers falling
over or from the side of escalators
• Data was collected into incidents where people
had fallen from or over the sides of escalators.
• The data collection date was cut off on 7th
November 2007 in order that analysis could be
undertaken.
• Since that date I am aware of a number of
further incidents.
4th April 2008 – Liverpool, UK
EIGHT KEY QUESTIONS
1. How many incidents are actually occurring?
2. Is there a trend for the number of incidents
occurring?
3. How many incidents involve fatal accidents?
4. Is there a trend for the number of fatal
incidents occurring?
5. How do the incidents occur?
6. What is the age distribution of the victims
7. What is the gender distribution?
8. Where are the incidents occurring?
OBSTRUCTIONS TO RESEARCH
• There is no single authoritative body that collects accident data
worldwide
• Escalator owners are reluctant to admit to incidents
• Escalator manufacturers are similarly reluctant
QUESTION (1)
HOW MANY INCIDENTS ARE ACTUALLY OCCURRING?
• 330 Incidents of falls over the side or from
the side of escalators have been located
over a period of 20 years between 1987
and 2007.
• An additional 31 incidents have been
located that occurred pre 1987 or are of an
unknown vintage.
QUESTION (2)
IS THERE A TREND FOR THE NUMBER OF INCIDENTS
OCCURRING?
• Plotting the number of accidents per
annum shows an upward trend in the
number of incidents occurring
QUESTION (2)
POSSIBLE REASONS FOR THE INCREASING TREND OF
INCIDENTS OCCURRING
• Possibly accidents per unit are actually increasing?
• Possibly due to an increase in number of escalators
installed worldwide
• Possibly due to an increase in the number of escalators
suspended in atria or open sided environments
• Possibly due to improved access to information via
internet
QUESTION (3)
HOW MANY INCIDENTS INVOLVE FATALITIES?
• Looking at the period 1987 to 2007 inclusive:
• 96 of the 330 incidents located involved fatal
accidents.
• This means that 29% of incidents identified
result in a fatality.
• This is considered to be worryingly high.
QUESTION (4)
IS THERE A TREND WITH THE NUMBER OF INCIDENTS
INVOLVING FATALITIES?
• Plotting the number of accidents per
annum shows an upward trend in the
number of fatal incidents occurring
QUESTION (5)
HOW DO THE INCIDENTS OCCUR?
• 14 standard accident types of how these
incidents occur have been identified
• Incidents of “falling over” occur
differently to “falling from”
• Incidents can differ between an up running
and a down running escalator
QUESTION (5)
HOW DO THE INCIDENTS OCCUR?
1.
Falling over the side owing to sitting on or sliding down the
handrail.
2.
Falling from the side owing to walking up or down the outer deck
using the handrail to secure oneself
3.
Falling from the side owing to holding onto the handrail and being
taken
4.
Falling after being taken by the handrail as a result of friction by
clothing.
5.
Falling after jumping between escalators or over the side of
escalators for entertainment purposes!
QUESTION (5)
HOW DO THE INCIDENTS OCCUR?
6.
Falling on the escalator with the subsequent ultimate event being
a fall over the side of the escalator.
7.
Falling over the side owing to leaning over the handrail
8.
Falling over the side owing to being carried by an elder who has
lost balance.
9.
Falling owing to parents/guardians sitting child on handrail and
then losing control of the child.
10.
Suicide
QUESTION (5)
HOW DO THE INCIDENTS OCCUR?
11.
Child being carried on parents shoulders on an escalator!
12.
Balustrade defect/collapse
13.
Jumping over the side to avoid an obstruction
14.
Unknown causation
TYPE (1) INCIDENT
FALLING DUE TO SITTING ON THE HANDRAIL
TYPE (2) INCIDENT
OUTER DECK ENCROACHMENT
TYPE (3) INCIDENT
FALLING AFTER HOLDING ONTO THE HANDRAIL
TYPE (3) or (4) INCIDENT
HOLDING ONTO THE HANDRAIL
POSSIBLY INITIALLY DUE TO CLOTHING FRICTION
• Being taken by the
handrail as a
result of friction or
holding on
TYPE (5) INCIDENT
WHEN ENTERTAINMENT GOES WRONG
TYPE (6) INCIDENT
FALLING ON THEN FALLING OVER
• Falling on the
escalator with the
subsequent ultimate
event being a fall over
the side
TYPE (13) INCIDENT
FALLING ON THEN FALLING OVER
• Jumping over the
handrail to avoid an
obstruction
ANOTHER DISCOVERY!
• It has been discovered that some incidents involve more than one
person falling over the balustrade during the same incident
• These tend to be situations where there has been a fight or the
balustrade has collapsed
QUESTION (6)
WHAT IS THE AGE DISTRIBUTION OF VICTIMS?
• Of the 330 incidents 146 involve children aged under 10
• This is the highest group in the analysis but accidents
occur right across the age bands but they tail off with
age
• This represents 44% of the incidents.
• This could be as high as 60% if some of the unknown
age incidents are included.
• The previous slide demonstrates that most
incidents involve children aged 10 and under
• These incidents tend to fall into two types;
gaining access to the outer deck and being
taken by the handrail
• The following slide demonstrates that the fatality
age distribution pattern is generally spread in the
younger age groups
• Based on the 20 year data, if we as an industry,
deal with the incidents involving under 10’s the
rate of incidence could reduce by about 44%
• I would suggest that the under 10’s are not
aware of the consequences of their actions and
therefore it is for us, as an industry, to resolve
• We could also reduce the number of fatalities by
25%
QUESTION (7)
WHAT IS THE GENDER DISTRIBUTION OF VICTIMS?
• It has become apparent that a disproportionate number of
incidents involve male victims
• 234 of the 330 incidents involved male victims
• This equates to 71%
• There are only 21 incidents where the gender is not known
so at worse the percentage could be 77%
• Fatalities have been found to involve 77% male incidents
QUESTION (8)
WHERE ARE THE INCIDENTS OCCURRING?
• The data suggest that incidents are occurring worldwide
• Incidents have been found in 35 countries
• This appears to eliminate cultural issues as being a
contributory factor to causation
• The majority of incidents occur in Europe and the USA
which is to be expected given these are the primary sales
markets
CAUSATION
• THE RESEARCH HAS ESTABLISHED THAT THREE FACTORS
HAVE TO BE PRESENT FOR AN INCIDENT OF THIS TYPE TO
OCCUR:
• A VOID IN WHICH TO FALL HAS TO BE PRESENT
• AN UNATTENDED CHILD HAS TO BE PRESENT
• THE INCIDENT WILL ALWAYS START AT THE BOARDING END
ESCALATOR DESIGN
CONSIDERATIONS
FRICTIONAL QUALITIES OF HANDRAILS
• THE EN115 STANDARD DOES NOT STATE ANY FRICTIONAL
QUALITIES FOR HANDRAILS.
• WITNESS STATEMENTS HAVE BEEN LOCATED STATING THAT
CHILDREN HAVE BEEN PICKED UP BY THE HANDRAIL AS A
RESULT OF CLOTHING CONTACT
HANDRAIL HEIGHTS
• THE EN115 STANDARD ALLOWS HANDRAIL HEIGHTS OF 900
TO 1100 MM FROM THE STEP SURFACE.
• THIS CONFLICTS WITH THE BUILDING REGULATIONS
REQUIREMENTS FOR GUARD RAILS WHEN AN ESCALATOR IS
INSTALLED IN AN OPEN ATRIUM AS STATIC GUARDS NEED
TO BE 1200 MM
• IN ADDITION ON A DOWN RUNNING 35° ESCALATOR THE
HANDRAIL WILL FALL AWAY BY 266 MM OVER THE LENGTH
OF A STEP DEPTH (380 MM)
• THIS WILL INCREASE THE LIKELIHOOD OF AN OVER THE SIDE
INCIDENT AS THE TURNING MOMENT IS BELOW MOST
HUMAN HIP HEIGHTS
• IT IS KNOWN THAT IN THE USA 35° ESCALATORS ARE NOT
PERMITTED
HANDRAIL DIMENSIONS
• THE EN115 STANDARDS
CALLS FOR HANDRAIL
WIDTHS TO BE BETWEEN
70 MM AND 100 MM.
• THIS CONFLICTS WITH
RESEARCH PUBLISHED BY
THE BUILDING RESEARCH
ESTABLISHMENT.
• THE ADDITIONAL WIDTH
ALSO INCREASES THE
SURFACE AREA WITH
RESPECT TO FRICTIONAL
INCIDENTS WITH CLOTHING
BALUSTRADE DESIGN
•
EN115 STANDARD STATES
THAT THE BALUSTRADE SHALL
HAVE NO PARTS ON WHICH A
PERSON WOULD NORMALLY
STAND.
•
MOST DESIGNS HAVE
HORIZONTAL DECKS
ASSISTING OUTER DECK
ENCROACHMENT
OUTER DECK ENCROACHMENT DETECTION
• THERE IS NO OUTER DECK ENCROACHMENT DETECTION
DEVICE
• SUCH A DEVICE COULD STOP AN ESCALATOR PRIOR TO A
CHILD BEING FORCED INTO THE SOFFIT AND FALLING
OUTER DECK ENCROACHMENT GUARD DESIGN
• OUTER DECK ENCROACHMENT GUARDS ARE NOT
DIMENSIONALLY SPECIFIED AND ARE INCONSISTENT FROM
MANUFACTURER TO MANUFACTURER
• THE NEW EN115 STANDARD HAS MOVED TOWARDS
DIMENSIONING ENCROACHMENT GUARDS WHICH IS A
POSITIVE MOVE
• IT IS ALSO KNOWN THAT CHILDREN HAVE BEEN KNOWN TO
HAVE BEEN PULLED OVER OR ROUND THE OLD STYLE
GUARDS BY HANGING ONTO THE HANDRAIL
POLICY CONSIDERATIONS
• I AM NOT SUGGESTING THAT ESCALATOR DESIGN NEEDS TO
CHANGE SIGNIFICANTLY.
• I AM SUGGESTING THAT POLICY DECISIONS AND CORRECT
SPECIFICATION WILL REDUCE THE NUMBER OF ACCIDENTS
OF THIS TYPE
• DO NOT USE 35 DEGREE MACHINES WITH VOIDS
• ALWAYS USE 1100 MM HANDRAIL HEIGHTS WITH VOIDS
• ENCOURAGE DESIGNERS NOT TO CREATE MULTI FLOOR
FALL POSSIBILITIES
• USE 70 MM HANDRAILS WHERE VOIDS EXIST
THE RESEARCH CONTINUES………………….
• If you would like a copy of the final research report or the MSc
research report into accidents involving trolleys and carts on
escalators please contact me at [email protected]